ASA UDP Dns reply dropped

Hello,
According to the ASA logs, a lot of dns packets (from root dns servers) are dropped because they exceed the limit of 512 bytes (size limit fixed in dns inspection).
It seems corresponding to DNSSEC packet.
Which value should I use for the DNS packet size limit ?
Some say 1024, others 4096...
Thanks

Hello Armand,
It would be more secure to work with the 1024, you can give it a try to that one and check if you keep getting DNS packets denied.
Here is one of the fix released from Cisco regarding the DNSSEC packet size:
policy-map type inspect dns preset_dns_map
parameters
message-length maximum client auto
If EDNS is used, the above command will allow DNS replies up to the length specified in the OPT record.
Regards,
Julio

Similar Messages

DNS reply filtering

Hi,
Am trying to make DNS filtering work as URL filtering cannot permit https traffic.
Config is as per below. The thing is that it blocks every url at the moment instead of just test - gmail.com as per regex
It looks simple on the paper but cannot make it work (
regex test "gmail\.com"
access-list http-user-vlan414-acl extended permit object-group http-inspect-ports 10.4.14.0 255.255.255.0 any
class-map type regex match-any DomainBlockList
description blocked domains
match regex test
class-map http-user-vlan414-class
match access-list http-user-vlan414-acl
policy-map type inspect dns vlan414-policy
parameters
message-length maximum 512
match domain-name regex class DomainBlockList
drop-connection log
policy-map http-main-policy-vlan414
class http-user-vlan414-class
inspect dns vlan414-policy
service-policy http-main-policy-vlan414 interface vlan414

Hello Arunas,
So If u set:
class-map http-user-vlan414-class
match any -
policy-map http-main-policy-vlan414
class http-user-vlan414-class
inspect dns vlan414-policy
Okey but have you applied to a service-policy?
What do you mean traffic drops?
Check my blog at http:laguiadelnetworking.com for further information.
Cheers,
Julio Carvajal Segura

URGENT: ASA Standard DNS Configuration Option????

All,
I am trying to implement "standard dns" on an ASA. I have not been able to find out how this is configured as opposed to: split-dns or tunnel-all-dns? Any pointers would be great.
Thanks in advance!!
Scott Jackson
Systems Engineer

Hi Scott,
This should help you to configure DNS for from the box traffic.
http://www.cisco.com/c/en/us/td/docs/security/asa/asa82/configuration/guide/config/basic.html#wp1080248
Regards,
Dinesh Moudgil
P.S. Please rate helpful posts.

CISCO ASA Enable DNS Lookup Problem

I have Cisco ASA 5510 , from ASA CLI i can not resolved the hostname. ( cisco.com or google.com)
At many form say do this.
1. Whilst in enable mode > enter configure terminal mode, then enable DNS Lookups.
CiscoASA#conf t
CiscoASA(config)# dns domain-lookup Outside
2. Then specify the external DNS Servers (Change IP addresses appropriately).
CiscoASA(config)# dns server-group DefaultDNS
CiscoASA(config-dns-server-group)# name-server 122.122.122.199
CiscoASA(config-dns-server-group)# name-server 122.122.122.198
CiscoASA(config-dns-server-group)# exit
3. Test it by pinging a name/URL.
CiscoASA(config)# ping www.20best.blogspot.com
Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to 123.123.123.123, timeout is 2 seconds:
But there is no command ( dns server-group ) in my ASA
Please tell me how to do this or any way
My ASA is showing only
ail-ASA# sh runn
: Saved
ASA Version 7.0(8)
hostname Mail-ASA
domain-name rawabiholding.com
enable password QuzxIf5jNzzT5kki encrypted
passwd 2KFQnbNIdI.2KYOU encrypted
names
name 172.16.0.94 Test-web-mail
name 172.16.5.63 Mail-server
name 172.16.0.40 Web-Mail
name 172.16.0.24 MX-A
name 172.16.0.93 Test-Mail-MX
name 172.16.1.55 DNS-1
name 172.16.1.17 Web-Server
name 172.16.0.41 Helpdesk.rawabiholding.com
name 172.16.0.98 Test-Server
no dns-guard
interface Ethernet0/0
nameif outside
security-level 10
ip address 82.118.161.34 255.255.255.224
interface Ethernet0/1
nameif LAN
security-level 100
ip address 172.16.1.65 255.255.252.0
interface Ethernet0/2
nameif inside-Mail
security-level 100
ip address 172.16.5.37 255.255.255.0
interface Management0/0
nameif management
security-level 100
ip address 192.168.100.1 255.255.255.0
management-only
banner exec ************* If you are not Rawabi IT Member Please logout ********
banner login ***************** Do not open or login , if you are not allowed *
ftp mode passive
dns domain-lookup outside
dns name-server 212.102.0.82
dns name-server 212.102.0.11
access-list outside_access_in extended permit tcp any host 82.118.161.35 eq pop3
access-list outside_access_in extended permit tcp any host 82.118.161.35 eq smt.

http://20best.blogspot.com
Dear Jennifer,
From Router-ISP, I check it is resolving the name to IP
but from ASA 5510 not, it giving error
Jennifer Halim wrote:Doesn't look like the DNS servers that you configured is resolving any DNS requests.I have just tried both DNS server, and it is refusing the DNS:> www.google.comServer: ns3.shabakah.net.saAddress: 212.102.0.82*** ns3.shabakah.net.sa can't find www.google.com: Query refused> www.google.comServer: [212.102.0.11]Address: 212.102.0.11*** [212.102.0.11] can't find www.google.com: Query refused
http://20best.blogspot.com/2011/06/visit-to-grand-canyon-in-10-days.html

Cisco ASA and DNS

We purchased a bunch of Cisco ASA 5505 for our branch offices. Offices are made up of less than 20 end points. We are using it as a firewall and DHCP server at hte moment but also assumed that it had DNS server capabilities. Basically use it as a SOHO router. My research thus far indicates that yes we can use the device as a dns server but it won't resolve locally defined hosts. So it can relay dns request to an external dns server but won't allow me to configured an a record on the device itself.
Can anyone verify this before I look into purchasing another device just to do local DNS server services?
Thanks!

Joe
As far as i know the ASA cannot act as a DNS server nor can it act as a DNS relay. What you can do is -
1) configure DNS servers on the ASA that can be used in certain situations for allowing the ASA to resolve a name to an IP. For example using the Botnet filter on the ASA, SSL certificates etc. require the ASA to be able to qurey external DNS servers.
But this is for use by the ASA itself ie. it is used to resolve names within the ASA config. It is not used to allow clients to ask the ASA to resolve DNS names for them. So it can neither act as a DNS server itself nor can it pass on clients DNS queries to DNS servers.
2) if you use the ASA to hand out IPs via DHCP you can add valid DNS servers within the DHCP config just as you can with Windows DHCP.
Jon

UDP Datagram Reply Issue

Hello Everyone....
I'm doing a project in which i need to send datagrams to clients waiting on particular port. I want the client to reply to the server's port from which the datagram is sent. Is this possible ?
I have tried this by creating a DatagramSocket with empty constructor and sent the packet to the particular port on client. In turn, on receiving the packet from the server, the client sends the reply to the port got from received DatagramPacket's getPort method.. But, I'm not getting the packet back to the server.
Please help me...
Thanking you in advance...
R. Kaja Mohideen

Received DatagramPacket already has source address and port set, so you could simply do:
packet.setData(.....);
socket.send(packet);

Cisco ASA rely HTTP port to HTTPS without using CNAME DNS-record

Hi all,
could anyone tell me Is it possible to configure ASA so when customer rely http://domain.com Cisco ASA rely to https://domain.com (it's similar with CName function of domain record).
P.S. resource of domain.com located behind ASA and DNS A-record rely on public ASA ip address
Thank you.

What version ASA are you running?
If the server has both static public and private IPs you could use NAT to redirect HTTP traffic to HTTPS based on IP.
object network PUBLIC_IP
host 1.1.1.1
object network REAL_IP
host 2.2.2.2
nat (inside,outside) static PUBLIC_IP http https
Keep in mind that you will also need a NAT statement that maintains https to the server.
Please remember to select a correct answer and rate helpful posts

Cisco ASA 5505 IPsec client VPN - Cannot connect to local hosts

I have created a Cisco IPsec vpn on my ASA using the VPN creation wizard. I am able to successfully connect to the vpn and seemingly join the network, but after I connect I am unable to connect to or ping any of the hosts on the network.
Checking the ASA I can see that a VPN session is open and my client reports that it is connected. If I attempt to ping the client from the ASA all packets are dropped.
I suspect it may be an issue with my firewall, but I am not really sure where to begin.
Here is a copy of my config, any pointers or tips are aprpeciated:
hostname mcfw
enable password Pt8fQ27yMZplioYq encrypted
passwd 2qaO2Gd6IBRkrRFm encrypted
names
interface Ethernet0/0
switchport access vlan 400
interface Ethernet0/1
switchport access vlan 400
interface Ethernet0/2
switchport access vlan 420
interface Ethernet0/3
switchport access vlan 420
interface Ethernet0/4
switchport access vlan 450
interface Ethernet0/5
switchport access vlan 450
interface Ethernet0/6
switchport access vlan 500
interface Ethernet0/7
switchport access vlan 500
interface Vlan400
nameif outside
security-level 0
ip address 58.13.254.10 255.255.255.248
interface Vlan420
nameif public
security-level 20
ip address 192.168.20.1 255.255.255.0
interface Vlan450
nameif dmz
security-level 50
ip address 192.168.10.1 255.255.255.0
interface Vlan500
nameif inside
security-level 100
ip address 192.168.0.1 255.255.255.0
ftp mode passive
clock timezone JST 9
same-security-traffic permit inter-interface
same-security-traffic permit intra-interface
object-group network DM_INLINE_NETWORK_1
network-object host 58.13.254.11
network-object host 58.13.254.13
object-group service ssh_2220 tcp
port-object eq 2220
object-group service ssh_2251 tcp
port-object eq 2251
object-group service ssh_2229 tcp
port-object eq 2229
object-group service ssh_2210 tcp
port-object eq 2210
object-group service DM_INLINE_TCP_1 tcp
group-object ssh_2210
group-object ssh_2220
object-group service zabbix tcp
port-object range 10050 10051
object-group service DM_INLINE_TCP_2 tcp
port-object eq www
group-object zabbix
port-object eq 9000
object-group protocol TCPUDP
protocol-object udp
protocol-object tcp
object-group service http_8029 tcp
port-object eq 8029
object-group network DM_INLINE_NETWORK_2
network-object host 192.168.20.10
network-object host 192.168.20.30
network-object host 192.168.20.60
object-group service imaps_993 tcp
description Secure IMAP
port-object eq 993
object-group service public_wifi_group
description Service allowed on the Public Wifi Group. Allows Web and Email.
service-object tcp-udp eq domain
service-object tcp-udp eq www
service-object tcp eq https
service-object tcp-udp eq 993
service-object tcp eq imap4
service-object tcp eq 587
service-object tcp eq pop3
service-object tcp eq smtp
access-list outside_access_in remark http traffic from outside
access-list outside_access_in extended permit tcp any object-group DM_INLINE_NETWORK_1 eq www
access-list outside_access_in remark ssh from outside to web1
access-list outside_access_in extended permit tcp any host 58.13.254.11 object-group ssh_2251
access-list outside_access_in remark ssh from outside to penguin
access-list outside_access_in extended permit tcp any host 58.13.254.10 object-group ssh_2229
access-list outside_access_in remark http from outside to penguin
access-list outside_access_in extended permit tcp any host 58.13.254.10 object-group http_8029
access-list outside_access_in remark ssh from outside to hub & studio
access-list outside_access_in extended permit tcp any host 58.13.254.13 object-group DM_INLINE_TCP_1
access-list outside_access_in remark dns service to hub
access-list outside_access_in extended permit object-group TCPUDP any host 58.13.254.13 eq domain
access-list dmz_access_in extended permit ip 192.168.10.0 255.255.255.0 any
access-list dmz_access_in extended permit tcp any host 192.168.10.251 object-group DM_INLINE_TCP_2
access-list public_access_in remark Web access to DMZ websites (mediastudio/civicrm)
access-list public_access_in extended permit object-group TCPUDP any object-group DM_INLINE_NETWORK_2 eq www
access-list public_access_in remark General web access. (HTTP, DNS & ICMP and Email)
access-list public_access_in extended permit object-group public_wifi_group any any
access-list inside_nat0_outbound extended permit ip 192.168.0.0 255.255.255.0 192.168.10.0 255.255.255.0
access-list inside_nat0_outbound extended permit ip 192.168.0.0 255.255.255.0 192.168.20.0 255.255.255.0
access-list inside_nat0_outbound extended permit ip any 192.168.0.80 255.255.255.240
access-list inside_nat0_outbound extended permit ip any 192.168.0.64 255.255.255.192
pager lines 24
logging enable
logging timestamp
logging buffered notifications
logging trap notifications
logging asdm debugging
logging from-address [email protected]
logging recipient-address [email protected] level warnings
logging host dmz 192.168.10.90 format emblem
logging permit-hostdown
mtu outside 1500
mtu public 1500
mtu dmz 1500
mtu inside 1500
ip local pool OfficePool 192.168.0.80-192.168.0.90 mask 255.255.255.0
ip local pool VPN_Pool 192.168.0.91-192.168.0.99 mask 255.255.255.0
no failover
icmp unreachable rate-limit 1 burst-size 1
no asdm history enable
arp timeout 60
global (outside) 1 interface
global (dmz) 2 interface
nat (public) 1 0.0.0.0 0.0.0.0
nat (dmz) 1 0.0.0.0 0.0.0.0
nat (inside) 0 access-list inside_nat0_outbound
nat (inside) 1 0.0.0.0 0.0.0.0
static (inside,outside) tcp interface 2229 192.168.0.29 2229 netmask 255.255.255.255
static (inside,outside) tcp interface 8029 192.168.0.29 www netmask 255.255.255.255
static (dmz,outside) 58.13.254.13 192.168.10.10 netmask 255.255.255.255 dns
static (dmz,outside) 58.13.254.11 192.168.10.30 netmask 255.255.255.255 dns
static (inside,dmz) 192.168.10.0 192.168.0.0 netmask 255.255.255.0 dns
static (dmz,inside) 192.168.0.251 192.168.10.251 netmask 255.255.255.255
static (dmz,public) 192.168.20.30 192.168.10.30 netmask 255.255.255.255 dns
static (dmz,public) 192.168.20.10 192.168.10.10 netmask 255.255.255.255 dns
access-group outside_access_in in interface outside
access-group public_access_in in interface public
access-group dmz_access_in in interface dmz
route outside 0.0.0.0 0.0.0.0 58.13.254.9 1
timeout xlate 3:00:00
timeout conn 1:00:00 half-closed 0:10:00 udp 0:02:00 icmp 0:00:02
timeout sunrpc 0:10:00 h323 0:05:00 h225 1:00:00 mgcp 0:05:00 mgcp-pat 0:05:00
timeout sip 0:30:00 sip_media 0:02:00 sip-invite 0:03:00 sip-disconnect 0:02:00
timeout sip-provisional-media 0:02:00 uauth 0:05:00 absolute
timeout tcp-proxy-reassembly 0:01:00
dynamic-access-policy-record DfltAccessPolicy
http server enable
http 192.168.0.0 255.255.255.0 inside
http 59.159.40.188 255.255.255.255 outside
no snmp-server location
no snmp-server contact
snmp-server enable traps snmp authentication linkup linkdown coldstart
sysopt noproxyarp dmz
sysopt noproxyarp inside
crypto ipsec transform-set ESP-AES-256-MD5 esp-aes-256 esp-md5-hmac
crypto ipsec transform-set ESP-DES-SHA esp-des esp-sha-hmac
crypto ipsec transform-set ESP-DES-MD5 esp-des esp-md5-hmac
crypto ipsec transform-set ESP-AES-192-MD5 esp-aes-192 esp-md5-hmac
crypto ipsec transform-set ESP-3DES-MD5 esp-3des esp-md5-hmac
crypto ipsec transform-set ESP-AES-256-SHA esp-aes-256 esp-sha-hmac
crypto ipsec transform-set ESP-AES-128-SHA esp-aes esp-sha-hmac
crypto ipsec transform-set ESP-AES-192-SHA esp-aes-192 esp-sha-hmac
crypto ipsec transform-set ESP-AES-128-MD5 esp-aes esp-md5-hmac
crypto ipsec transform-set TRANS_ESP_3DES_SHA esp-3des esp-sha-hmac
crypto ipsec transform-set TRANS_ESP_3DES_SHA mode transport
crypto ipsec transform-set ESP-3DES-SHA esp-3des esp-sha-hmac
crypto ipsec security-association lifetime seconds 28800
crypto ipsec security-association lifetime kilobytes 4608000
crypto dynamic-map SYSTEM_DEFAULT_CRYPTO_MAP 65535 set pfs group1
crypto dynamic-map SYSTEM_DEFAULT_CRYPTO_MAP 65535 set transform-set ESP-AES-128-SHA ESP-AES-128-MD5 ESP-AES-192-SHA ESP-AES-192-MD5 ESP-AES-256-SHA ESP-AES-256-MD5 ESP-3DES-SHA ESP-3DES-MD5 ESP-DES-SHA ESP-DES-MD5
crypto map inside_map 65535 ipsec-isakmp dynamic SYSTEM_DEFAULT_CRYPTO_MAP
crypto map inside_map interface inside
crypto map outside_map 65535 ipsec-isakmp dynamic SYSTEM_DEFAULT_CRYPTO_MAP
crypto map outside_map interface outside
crypto map public_map 65535 ipsec-isakmp dynamic SYSTEM_DEFAULT_CRYPTO_MAP
crypto map public_map interface public
crypto isakmp enable outside
crypto isakmp enable public
crypto isakmp enable inside
crypto isakmp policy 5
authentication pre-share
encryption 3des
hash sha
group 2
lifetime 86400
crypto isakmp policy 10
authentication pre-share
encryption des
hash sha
group 2
lifetime 86400
telnet timeout 5
ssh 59.159.40.188 255.255.255.255 outside
ssh 192.168.0.0 255.255.255.0 inside
ssh timeout 20
console timeout 0
dhcpd dns 61.122.112.97 61.122.112.1
dhcpd auto_config outside
dhcpd address 192.168.20.200-192.168.20.254 public
dhcpd enable public
dhcpd address 192.168.10.190-192.168.10.195 dmz
dhcpd enable dmz
dhcpd address 192.168.0.200-192.168.0.254 inside
dhcpd enable inside
threat-detection basic-threat
threat-detection statistics access-list
threat-detection statistics host number-of-rate 2
no threat-detection statistics tcp-intercept
ntp server 130.54.208.201 source public
webvpn
group-policy DefaultRAGroup internal
group-policy DefaultRAGroup attributes
dns-server value 61.122.112.97 61.122.112.1
vpn-tunnel-protocol l2tp-ipsec
group-policy CiscoASA internal
group-policy CiscoASA attributes
dns-server value 61.122.112.97 61.122.112.1
vpn-tunnel-protocol IPSec
username mcit password 4alT9CZ8ayD8O8Xg encrypted privilege 15
tunnel-group DefaultRAGroup general-attributes
address-pool VPN_Pool
default-group-policy DefaultRAGroup
tunnel-group DefaultRAGroup ipsec-attributes
pre-shared-key *****
tunnel-group ocmc type remote-access
tunnel-group ocmc general-attributes
address-pool OfficePool
tunnel-group ocmc ipsec-attributes
pre-shared-key *****
tunnel-group CiscoASA type remote-access
tunnel-group CiscoASA general-attributes
address-pool VPN_Pool
default-group-policy CiscoASA
tunnel-group CiscoASA ipsec-attributes
pre-shared-key *****
class-map inspection_default
match default-inspection-traffic
policy-map type inspect dns preset_dns_map
parameters
message-length maximum client auto
message-length maximum 512
policy-map global_policy
class inspection_default
inspect dns preset_dns_map
inspect ftp
inspect h323 h225
inspect h323 ras
inspect ip-options
inspect netbios
inspect rsh
inspect rtsp
inspect skinny
inspect esmtp
inspect sqlnet
inspect sunrpc
inspect tftp
inspect sip
inspect xdmcp
service-policy global_policy global
smtp-server 192.168.10.10
prompt hostname context
call-home
profile CiscoTAC-1
no active
destination address http https://tools.cisco.com/its/service/oddce/services/DDCEService
destination address email [email protected]
destination transport-method http
subscribe-to-alert-group diagnostic
subscribe-to-alert-group environment
subscribe-to-alert-group inventory periodic monthly
subscribe-to-alert-group configuration periodic monthly
subscribe-to-alert-group telemetry periodic daily
Cryptochecksum:222d6dcb583b5f5abc51a2251026f7f2
: end
asdm location 192.168.10.10 255.255.255.255 inside
asdm location 192.168.0.29 255.255.255.255 inside
asdm location 58.13.254.10 255.255.255.255 inside
no asdm history enable

Hi Conor,
What is your local net ? I see only one default route for outside network. Dont you need a route inside for your local network.
Regards,
Umair

CISCO ASA-5505 - Is it hindering our Internet service?

I'm responsible for a small network (300 wired/ 500-600 wireless smart devices) in a High School. We're running a couple of Windows 2008 servers. We have very few network applications and a 10MG Ethernet line for internet. Typically on we're getting 6 mg on upload and 1 or 2 on download. I'm wondering if the Cisco could be better configured to give us higher speeds, taking full advantage of our 10 mg line.
I have attached our current config.   Being a novice, I have tried a few changes to the configuration, assigning each of the 7 circuits to inside or outside.
But I could use an experts opinion.    We are a school environment, so classrooms will typically stream videos, surf internet, not extensive uploading , but it is getting more and more necessary as teachers update their web sites.
Before I go in and say we need more bandwidth, I'd like to feel confident that the router is doing all it can.   Thanks for taking the time..
I have attached the current config:
: Saved
ASA Version 8.2(5)
hostname ciscoasa
domain-name hnedu.com
enable password mnpTCRVkk1.ZjiWJ encrypted
passwd 2KFQnbNIdI.2KYOU encrypted
names
interface Ethernet0/0
switchport access vlan 2
speed 100
duplex full
interface Ethernet0/1
switchport access vlan 2
speed 100
duplex full
interface Ethernet0/2
speed 100
duplex full
interface Ethernet0/3
speed 100
duplex full
interface Ethernet0/4
speed 100
duplex full
interface Ethernet0/5
speed 100
duplex full
interface Ethernet0/6
interface Ethernet0/7
interface Vlan1
nameif inside
security-level 100
ip address 10.0.0.1 255.255.0.0
interface Vlan2
description External Connection
nameif outside
security-level 0
ip address 209.117.123.226 255.255.255.224
ftp mode passive
dns domain-lookup inside
dns domain-lookup outside
dns server-group DefaultDNS
name-server 10.0.0.2
name-server 10.0.0.4
domain-name hnedu.com
same-security-traffic permit inter-interface
same-security-traffic permit intra-interface
object-group network RDP_static
object-group service RemoteDesktop tcp-udp
description Windows Remote Desktop Access
port-object eq 3389
object-group protocol TCPUDP
protocol-object udp
protocol-object tcp
access-list inside_access_in extended permit ip any any
access-list outside_access_in extended permit tcp any host 209.117.123.227 eq www
access-list outside_access_in remark remote desktop to cproom desktop
access-list outside_access_in extended permit object-group TCPUDP any host 209.117.123.228 eq 3389
access-list outside extended permit tcp any host 10.0.1.33 eq 3389
access-list Napoleons_splitTunnelAcl standard permit 10.0.0.0 255.255.0.0
access-list inside_nat0_outbound extended permit ip 10.0.0.0 255.255.0.0 10.0.0.64 255.255.255.192
pager lines 24
logging asdm informational
mtu inside 1500
mtu outside 1500
ip local pool VPNUsers 10.0.0.80-10.0.0.99 mask 255.255.0.0
icmp unreachable rate-limit 1 burst-size 1
no asdm history enable
arp timeout 14400
global (outside) 1 interface
nat (inside) 0 access-list inside_nat0_outbound
nat (inside) 1 0.0.0.0 0.0.0.0
static (inside,outside) 209.117.123.227 10.0.0.6 netmask 255.255.255.255
static (inside,outside) 209.117.123.228 10.0.4.252 netmask 255.255.255.255
access-group inside_access_in in interface inside control-plane
access-group outside_access_in in interface outside
route outside 0.0.0.0 0.0.0.0 209.117.123.225 1
timeout xlate 3:00:00
timeout conn 1:00:00 half-closed 0:10:00 udp 0:02:00 icmp 0:00:02
timeout sunrpc 0:10:00 h323 0:05:00 h225 1:00:00 mgcp 0:05:00 mgcp-pat 0:05:00
timeout sip 0:30:00 sip_media 0:02:00 sip-invite 0:03:00 sip-disconnect 0:02:00
timeout sip-provisional-media 0:02:00 uauth 0:05:00 absolute
timeout tcp-proxy-reassembly 0:01:00
timeout floating-conn 0:00:00
dynamic-access-policy-record DfltAccessPolicy
http server enable
http 192.168.1.0 255.255.255.0 inside
http 10.0.0.0 255.255.0.0 inside
no snmp-server location
no snmp-server contact
snmp-server enable traps snmp authentication linkup linkdown coldstart
crypto ipsec transform-set ESP-3DES-SHA esp-3des esp-sha-hmac
crypto ipsec transform-set ESP-AES-256-MD5 esp-aes-256 esp-md5-hmac
crypto ipsec transform-set ESP-DES-SHA esp-des esp-sha-hmac
crypto ipsec transform-set ESP-DES-MD5 esp-des esp-md5-hmac
crypto ipsec transform-set ESP-AES-192-MD5 esp-aes-192 esp-md5-hmac
crypto ipsec transform-set ESP-3DES-MD5 esp-3des esp-md5-hmac
crypto ipsec transform-set ESP-AES-256-SHA esp-aes-256 esp-sha-hmac
crypto ipsec transform-set ESP-AES-128-SHA esp-aes esp-sha-hmac
crypto ipsec transform-set ESP-AES-192-SHA esp-aes-192 esp-sha-hmac
crypto ipsec transform-set ESP-AES-128-MD5 esp-aes esp-md5-hmac
crypto ipsec security-association lifetime seconds 28800
crypto ipsec security-association lifetime kilobytes 4608000
crypto dynamic-map SYSTEM_DEFAULT_CRYPTO_MAP 65535 set pfs group1
crypto dynamic-map SYSTEM_DEFAULT_CRYPTO_MAP 65535 set transform-set ESP-AES-128-SHA ESP-AES-128-MD5 ESP-AES-192-SHA ESP-AES-192-MD5 ESP-AES-256-SHA ESP-AES-256-MD5 ESP-3DES-SHA ESP-3DES-MD5 ESP-DES-SHA ESP-DES-MD5
crypto map outside_map 65535 ipsec-isakmp dynamic SYSTEM_DEFAULT_CRYPTO_MAP
crypto map outside_map interface outside
crypto ca trustpoint _SmartCallHome_ServerCA
crl configure
crypto ca certificate chain _SmartCallHome_ServerCA
certificate ca 6ecc7aa5a7032009b8cebcf4e952d491
    308205ec 308204d4 a0030201 0202106e cc7aa5a7 032009b8 cebcf4e9 52d49130
    0d06092a 864886f7 0d010105 05003081 ca310b30 09060355 04061302 55533117
    30150603 55040a13 0e566572 69536967 6e2c2049 6e632e31 1f301d06 0355040b
    13165665 72695369 676e2054 72757374 204e6574 776f726b 313a3038 06035504
    0b133128 63292032 30303620 56657269 5369676e 2c20496e 632e202d 20466f72
    20617574 686f7269 7a656420 75736520 6f6e6c79 31453043 06035504 03133c56
    65726953 69676e20 436c6173 73203320 5075626c 69632050 72696d61 72792043
    65727469 66696361 74696f6e 20417574 686f7269 7479202d 20473530 1e170d31
    30303230 38303030 3030305a 170d3230 30323037 32333539 35395a30 81b5310b
    30090603 55040613 02555331 17301506 0355040a 130e5665 72695369 676e2c20
    496e632e 311f301d 06035504 0b131656 65726953 69676e20 54727573 74204e65
    74776f72 6b313b30 39060355 040b1332 5465726d 73206f66 20757365 20617420
    68747470 733a2f2f 7777772e 76657269 7369676e 2e636f6d 2f727061 20286329
    3130312f 302d0603 55040313 26566572 69536967 6e20436c 61737320 33205365
    63757265 20536572 76657220 4341202d 20473330 82012230 0d06092a 864886f7
    0d010101 05000382 010f0030 82010a02 82010100 b187841f c20c45f5 bcab2597
    a7ada23e 9cbaf6c1 39b88bca c2ac56c6 e5bb658e 444f4dce 6fed094a d4af4e10
    9c688b2e 957b899b 13cae234 34c1f35b f3497b62 83488174 d188786c 0253f9bc
    7f432657 5833833b 330a17b0 d04e9124 ad867d64 12dc744a 34a11d0a ea961d0b
    15fca34b 3bce6388 d0f82d0c 948610ca b69a3dca eb379c00 48358629 5078e845
    63cd1941 4ff595ec 7b98d4c4 71b350be 28b38fa0 b9539cf5 ca2c23a9 fd1406e8
    18b49ae8 3c6e81fd e4cd3536 b351d369 ec12ba56 6e6f9b57 c58b14e7 0ec79ced
    4a546ac9 4dc5bf11 b1ae1c67 81cb4455 33997f24 9b3f5345 7f861af3 3cfa6d7f
    81f5b84a d3f58537 1cb5a6d0 09e4187b 384efa0f 02030100 01a38201 df308201
    db303406 082b0601 05050701 01042830 26302406 082b0601 05050730 01861868
    7474703a 2f2f6f63 73702e76 65726973 69676e2e 636f6d30 12060355 1d130101
    ff040830 060101ff 02010030 70060355 1d200469 30673065 060b6086 480186f8
    45010717 03305630 2806082b 06010505 07020116 1c687474 70733a2f 2f777777
    2e766572 69736967 6e2e636f 6d2f6370 73302a06 082b0601 05050702 02301e1a
    1c687474 70733a2f 2f777777 2e766572 69736967 6e2e636f 6d2f7270 61303406
    03551d1f 042d302b 3029a027 a0258623 68747470 3a2f2f63 726c2e76 65726973
    69676e2e 636f6d2f 70636133 2d67352e 63726c30 0e060355 1d0f0101 ff040403
    02010630 6d06082b 06010505 07010c04 61305fa1 5da05b30 59305730 55160969
    6d616765 2f676966 3021301f 30070605 2b0e0302 1a04148f e5d31a86 ac8d8e6b
    c3cf806a d448182c 7b192e30 25162368 7474703a 2f2f6c6f 676f2e76 65726973
    69676e2e 636f6d2f 76736c6f 676f2e67 69663028 0603551d 11042130 1fa41d30
    1b311930 17060355 04031310 56657269 5369676e 4d504b49 2d322d36 301d0603
    551d0e04 1604140d 445c1653 44c1827e 1d20ab25 f40163d8 be79a530 1f060355
    1d230418 30168014 7fd365a7 c2ddecbb f03009f3 4339fa02 af333133 300d0609
    2a864886 f70d0101 05050003 82010100 0c8324ef ddc30cd9 589cfe36 b6eb8a80
    4bd1a3f7 9df3cc53 ef829ea3 a1e697c1 589d756c e01d1b4c fad1c12d 05c0ea6e
    b2227055 d9203340 3307c265 83fa8f43 379bea0e 9a6c70ee f69c803b d937f47a
    6decd018 7d494aca 99c71928 a2bed877 24f78526 866d8705 404167d1 273aeddc
    481d22cd 0b0b8bbc f4b17bfd b499a8e9 762ae11a 2d876e74 d388dd1e 22c6df16
    b62b8214 0a945cf2 50ecafce ff62370d ad65d306 4153ed02 14c8b558 28a1ace0
    5becb37f 954afb03 c8ad26db e6667812 4ad99f42 fbe198e6 42839b8f 8f6724e8
    6119b5dd cdb50b26 058ec36e c4c875b8 46cfe218 065ea9ae a8819a47 16de0c28
    6c2527b9 deb78458 c61f381e a4c4cb66
quit
crypto isakmp enable outside
crypto isakmp policy 10
authentication pre-share
encryption 3des
hash sha
group 2
lifetime 86400
telnet timeout 5
ssh timeout 5
console timeout 0
management-access inside
dhcp-client update dns server none
dhcpd dns 10.0.0.2 10.0.0.4
dhcpd wins 10.0.0.2 10.0.0.4
dhcpd domain holyname.com
dhcpd option 5 ip 10.0.0.2 10.0.0.4 interface inside
dhcpd option 6 ip 10.0.0.2 10.0.0.2 interface inside
dhcprelay server 10.0.0.2 inside
dhcprelay server 10.0.0.4 inside
threat-detection basic-threat
threat-detection statistics access-list
no threat-detection statistics tcp-intercept
webvpn
group-policy Napoleons internal
group-policy Napoleons attributes
wins-server value 10.0.0.2 10.0.0.4
dns-server value 10.0.0.2 10.0.0.4
vpn-tunnel-protocol IPSec
split-tunnel-policy tunnelspecified
split-tunnel-network-list value Napoleons_splitTunnelAcl
default-domain value holyname.com
username bpenza password LTg/b/c3kPWfC8KM encrypted privilege 0
username bpenza attributes
vpn-group-policy Napoleons
tunnel-group Napoleons type remote-access
tunnel-group Napoleons general-attributes
address-pool VPNUsers
default-group-policy Napoleons
tunnel-group Napoleons ipsec-attributes
pre-shared-key *****
prompt hostname context
call-home reporting anonymous
Cryptochecksum:822ecccad298ebbc4063c4567a7159c3
: end
no asdm history enable

The payload option commonly used to perform NAT, between devices on overlapping networks that share the same IP address. For example, when an outside device sends a DNS query to 172.16.5.13, in order to reach an inside device 172.16.2.13, the local address inside the payload of the DNS reply is translated to a global address according to the relevant NAT rule.
Perhaps, the Cisco's DNS Doctoring method would work fine for you.
http://www.cisco.com/en/US/products/ps6120/products_configuration_example09186a00807968c8.shtml
Regards,
Ram

Verification on the asa 8.4 5505 about PAT and port forwarding.

hi all
ihae topology as blow :
inside------------eth0/1-------asa---eth0/7---------outside-------------------internet
my goal is
i want to make pat of inside network (10.66.12.0/24) with outside interface when it request the internet
also ,
i need port forwaridng to following hosts :
10.66.12.122 to 3389
10.66.12.249 to http
10.66.12.249 to https
10.66.12.249 to citrix
=============================================================
just m i need somebody to check my config it is correct
=============================================================
i have asda 5505 with :
ASAAAAA(config)# sh version
Cisco Adaptive Security Appliance Software Version 8.4(2)
Device Manager Version 6.4(5)
Compiled on Wed 15-Jun-11 18:17 by builders
System image file is "disk0:/asa842-k8.bin"
Config file at boot was "startup-config"
ASAAAAA up 1 hour 32 mins
Hardware:   ASA5505, 512 MB RAM, CPU Geode 500 MHz
Internal ATA Compact Flash, 128MB
BIOS Flash M50FW016 @ 0xfff00000, 2048KB
Encryption hardware device : Cisco ASA-5505 on-board accelerator (revision 0x0)
                             Boot microcode        : CN1000-MC-BOOT-2.00
                             SSL/IKE microcode     : CNLite-MC-SSLm-PLUS-2.03
                             IPSec microcode       : CNlite-MC-IPSECm-MAIN-2.06
                             Number of accelerators: 1
0: Int: Internal-Data0/0    : address is d48c.b597.ce35, irq 11
1: Ext: Ethernet0/0         : address is d48c.b597.ce2d, irq 255
2: Ext: Ethernet0/1         : address is d48c.b597.ce2e, irq 255
3: Ext: Ethernet0/2         : address is d48c.b597.ce2f, irq 255
4: Ext: Ethernet0/3         : address is d48c.b597.ce30, irq 255
5: Ext: Ethernet0/4         : address is d48c.b597.ce31, irq 255
6: Ext: Ethernet0/5         : address is d48c.b597.ce32, irq 255
7: Ext: Ethernet0/6         : address is d48c.b597.ce33, irq 255
8: Ext: Ethernet0/7         : address is d48c.b597.ce34, irq 255
9: Int: Internal-Data0/1    : address is 0000.0003.0002, irq 255
10: Int: Not used            : irq 255
11: Int: Not used            : irq 255
Licensed features for this platform:
Maximum Physical Interfaces       : 8              perpetual
VLANs                             : 3              DMZ Restricted
Dual ISPs                         : Disabled       perpetual
VLAN Trunk Ports                  : 0              perpetual
Inside Hosts                      : 50             perpetual
Failover                          : Disabled       perpetual
VPN-DES                           : Enabled        perpetual
VPN-3DES-AES                      : Enabled        perpetual
AnyConnect Premium Peers          : 2              perpetual
AnyConnect Essentials             : Disabled       perpetual
Other VPN Peers                   : 10             perpetual
Total VPN Peers                   : 25             perpetual
Shared License                    : Disabled       perpetual
AnyConnect for Mobile             : Disabled       perpetual
AnyConnect for Cisco VPN Phone    : Disabled       perpetual
Advanced Endpoint Assessment      : Disabled       perpetual
UC Phone Proxy Sessions           : 2              perpetual
Total UC Proxy Sessions           : 2              perpetual
Botnet Traffic Filter             : Disabled       perpetual
Intercompany Media Engine         : Disabled       perpetual
This platform has a Base license.
Serial Number: JMX162740GP
Running Permanent Activation Key: 0x6801f547 0xe81c57c4 0x20f339f4 0xaaf48040 0x
480e2fbc
Configuration register is 0x100003
Configuration last modified by enable_15 at 23:58:15.999 UTC Wed Jan 22 2014
ASAAAAA(config)# sh run
: Saved
ASA Version 8.4(2)
hostname ASAAAAA
enable password ffffCCSH encrypted
passwd 2KFfffff2KYOU encrypted
names
interface Ethernet0/0
interface Ethernet0/1
interface Ethernet0/2
interface Ethernet0/3
interface Ethernet0/4
interface Ethernet0/5
interface Ethernet0/6
interface Ethernet0/7
switchport access vlan 2
interface Vlan1
nameif ins
security-level 100
ip address 10.66.12.1 255.255.255.0
interface Vlan2
nameif outside
security-level 50
ip address x.x.55.34 255.255.255.248
boot system disk0:/asa842-k8.bin
ftp mode passive
same-security-traffic permit inter-interface
same-security-traffic permit intra-interface
object network obj_any
subnet 0.0.0.0 0.0.0.0
object network obj-0.0.0.0
host 0.0.0.0
object network localsubnet
subnet 10.66.12.0 255.255.255.0
description localsubnet
object network HTTP-Host
host 10.66.12.249
description web server
object network HTTPS-HOST
host 10.66.12.249
description Https
object network RDP-Host
host 10.66.12.122
description RDP host
object network citrix-host
host 10.66.12.249
description citrix
object service rdp
service tcp destination eq 3389
object service https
service tcp destination eq https
object service citrix
service tcp destination eq 2598
object service http
service tcp destination eq www
object-group network RDP-REDIRECT
object-group network HTTP-REDIRECT
object-group network HTTPS-REDIRECT
object-group network CITRIX-ICA-HDX-REDIRECTION
object-group network CITRIX-ICA-SESSION-RELIABILITY-REDIRECTION
object-group service CITRIX-ICA-HDX
object-group service CITRIX-SR
object-group service RDP
object-group network MY-insideNET
network-object 10.66.12.0 255.255.255.0
object-group service DM_INLINE_SERVICE_1
service-object object citrix
service-object object http
service-object object https
service-object object rdp
access-list outside_access_in extended permit object-group DM_INLINE_SERVICE_1 a
ny interface outside
pager lines 24
mtu ins 1500
mtu outside 1500
icmp unreachable rate-limit 1 burst-size 1
asdm image disk0:/asdm-645.bin
no asdm history enable
arp timeout 14400
nat (ins,outside) source static RDP-Host interface service rdp rdp
nat (ins,outside) source static HTTP-Host interface service http http
nat (ins,outside) source static citrix-host interface service citrix citrix
object network obj_any
nat (ins,outside) dynamic obj-0.0.0.0
object network localsubnet
nat (ins,outside) dynamic interface
access-group outside_access_in in interface outside
route outside 0.0.0.0 0.0.0.0 x.x.55.33 1
timeout xlate 3:00:00
timeout conn 1:00:00 half-closed 0:10:00 udp 0:02:00 icmp 0:00:02
timeout sunrpc 0:10:00 h323 0:05:00 h225 1:00:00 mgcp 0:05:00 mgcp-pat 0:05:00
timeout sip 0:30:00 sip_media 0:02:00 sip-invite 0:03:00 sip-disconnect 0:02:00
timeout sip-provisional-media 0:02:00 uauth 0:05:00 absolute
timeout tcp-proxy-reassembly 0:01:00
timeout floating-conn 0:00:00
dynamic-access-policy-record DfltAccessPolicy
user-identity default-domain LOCAL
aaa authentication http console LOCAL
aaa authentication ssh console LOCAL
aaa authentication telnet console LOCAL
http server enable
http 10.66.12.0 255.255.255.0 ins
http 0.0.0.0 0.0.0.0 outside
no snmp-server location
no snmp-server contact
snmp-server enable traps snmp authentication linkup linkdown coldstart
crypto ca trustpoint _SmartCallHome_ServerCA
crl configure
crypto ca certificate chain _SmartCallHome_ServerCA
certificate ca 6ecc7aa5a7032009b8cebcf4e952d491
    308205ec 308204d4 a0030201 0202106e cc7aa5a7 032009b8 cebcf4e9 52d49130
    0d06092a 864886f7 0d010105 05003081 ca310b30 09060355 04061302 55533117
    30150603 55040a13 0e566572 69536967 6e2c2049 6e632e31 1f301d06 0355040b
    13165665 72695369 676e2054 72757374 204e6574 776f726b 313a3038 06035504
    0b133128 63292032 30303620 56657269 5369676e 2c20496e 632e202d 20466f72
    20617574 686f7269 7a656420 75736520 6f6e6c79 31453043 06035504 03133c56
    65726953 69676e20 436c6173 73203320 5075626c 69632050 72696d61 72792043
    65727469 66696361 74696f6e 20417574 686f7269 7479202d 20473530 1e170d31
    30303230 38303030 3030305a 170d3230 30323037 32333539 35395a30 81b5310b
    30090603 55040613 02555331 17301506 0355040a 130e5665 72695369 676e2c20
    496e632e 311f301d 06035504 0b131656 65726953 69676e20 54727573 74204e65
    74776f72 6b313b30 39060355 040b1332 5465726d 73206f66 20757365 20617420
    68747470 733a2f2f 7777772e 76657269 7369676e 2e636f6d 2f727061 20286329
    3130312f 302d0603 55040313 26566572 69536967 6e20436c 61737320 33205365
    63757265 20536572 76657220 4341202d 20473330 82012230 0d06092a 864886f7
    0d010101 05000382 010f0030 82010a02 82010100 b187841f c20c45f5 bcab2597
    a7ada23e 9cbaf6c1 39b88bca c2ac56c6 e5bb658e 444f4dce 6fed094a d4af4e10
    9c688b2e 957b899b 13cae234 34c1f35b f3497b62 83488174 d188786c 0253f9bc
    7f432657 5833833b 330a17b0 d04e9124 ad867d64 12dc744a 34a11d0a ea961d0b
    15fca34b 3bce6388 d0f82d0c 948610ca b69a3dca eb379c00 48358629 5078e845
    63cd1941 4ff595ec 7b98d4c4 71b350be 28b38fa0 b9539cf5 ca2c23a9 fd1406e8
    18b49ae8 3c6e81fd e4cd3536 b351d369 ec12ba56 6e6f9b57 c58b14e7 0ec79ced
    4a546ac9 4dc5bf11 b1ae1c67 81cb4455 33997f24 9b3f5345 7f861af3 3cfa6d7f
    81f5b84a d3f58537 1cb5a6d0 09e4187b 384efa0f 02030100 01a38201 df308201
    db303406 082b0601 05050701 01042830 26302406 082b0601 05050730 01861868
    7474703a 2f2f6f63 73702e76 65726973 69676e2e 636f6d30 12060355 1d130101
    ff040830 060101ff 02010030 70060355 1d200469 30673065 060b6086 480186f8
    45010717 03305630 2806082b 06010505 07020116 1c687474 70733a2f 2f777777
    2e766572 69736967 6e2e636f 6d2f6370 73302a06 082b0601 05050702 02301e1a
    1c687474 70733a2f 2f777777 2e766572 69736967 6e2e636f 6d2f7270 61303406
    03551d1f 042d302b 3029a027 a0258623 68747470 3a2f2f63 726c2e76 65726973
    69676e2e 636f6d2f 70636133 2d67352e 63726c30 0e060355 1d0f0101 ff040403
    02010630 6d06082b 06010505 07010c04 61305fa1 5da05b30 59305730 55160969
    6d616765 2f676966 3021301f 30070605 2b0e0302 1a04148f e5d31a86 ac8d8e6b
    c3cf806a d448182c 7b192e30 25162368 7474703a 2f2f6c6f 676f2e76 65726973
    69676e2e 636f6d2f 76736c6f 676f2e67 69663028 0603551d 11042130 1fa41d30
    1b311930 17060355 04031310 56657269 5369676e 4d504b49 2d322d36 301d0603
    481d22cd 0b0b8bbc f4b17bfd b499a8e9 762ae11a 2d876e74 d388dd1e 22c6df16
    b62b8214 0a945cf2 50ecafce ff62370d ad65d306 4153ed02 14c8b558 28a1ace0
    5becb37f 954afb03 c8ad26db e6667812 4ad99f42 fbe198e6 42839b8f 8f6724e8
    6119b5dd cdb50b26 058ec36e c4c875b8 46cfe218 065ea9ae a8819a47 16de0c28
    6c2527b9 deb78458 c61f381e a4c4cb66
quit
telnet timeout 5
ssh timeout 5
console timeout 0
threat-detection basic-threat
threat-detection statistics access-list
no threat-detection statistics tcp-intercept
webvpn
username ADMIN password 5iEuCUW0P3ThngqY encrypted privilege 15
username cisco password eT0.bmvcLOAQcNEL encrypted privilege 15
prompt hostname context
call-home reporting anonymous
call-home
profile CiscoTAC-1
no active
destination address http https://tools.cisco.com/its/service/oddce/services/DD
CEService
destination address email [email protected]
destination transport-method http
subscribe-to-alert-group diagnostic
subscribe-to-alert-group environment
subscribe-to-alert-group inventory periodic monthly
subscribe-to-alert-group configuration periodic monthly
subscribe-to-alert-group telemetry periodic daily
Cryptochecksum:65c9b8c35749959d1159e162ff106166
: end
=======================================================
i configured PAT , PORTFORWARD and ACCESS RULES
just want to mae verification to my work
regards

Hi,
Dont think I can really give you an answer but thought I'd write anyway.
It does seem on the basis of the documentation of the ASA (8.4) that with Twice NAT you wont be able to do any modifications to the DNS replies.
Heres one quote from Configuration Guide
Gonfiguring Network Address Translation -> Information About NAT -> DNS and NAT
If you configure a twice NAT rule, you cannot configure DNS modification if you specify the sourceaddress as well as the destination address. These kinds of rules can potentially have a differenttranslation for a single address when going to A vs. B. Therefore, the ASA cannot accurately match theIP address inside the DNS reply to the correct twice NAT rule; the DNS reply does not containinformation about which source/destination address combination was in the packet that prompted theDNS request.
So if I'm not totally wrong I guess your options might be to either
Start doing changes to the local DNS server directly?
Separate the remote overlapping network from your current firewall with another firewall device?
I dont know the whole setup so this might be impossible
Thinking that if the NAT for the remote overlapping network was done on another firewall it could do the DNS reply changes before they arrived on your ASA from the remote DNS server?
I have not really had to tackle such a situation before. I most commonly run into situations where a customer has public IP configured with 1:1 Static NAT and there is no DNS parameter in the Static NAT configuration while the customer tries to use the DNS name to connect to their local server.
Just some of my thoughts. Maybe someone else might have more expirience with same type of situations.
- Jouni

ASA max concurrent connections

If I have a thousand nodes from the public each perform a UDP ping to a server behind the ASA, does each count as a concurrent connection?

Hi,
I imagine it does.
Also I guess if we are talking about just some random UDP traffic it would also mean that the default timeout for a connection would be 2min. The most usual UDP traffic would probably be DNS querys. In those cases I presume though that the UDP connections dont stay on firewall for long as long as the firewall sees the DNS reply.
But as I said if we are talking about some random UDP traffic that is allowed through the firewall I would guess it stays in the connection table of the firewall for a couple of minutes. So you might be looking at 1000 concurrent connections or even more?
I have once witnessed a single server sending so much UDP traffic that it reached the connection limit of an ASA5540 which is 400 000 concurrent connections.
- Jouni

DNS Inspection Denial of Service Vulnerability

Advisory ID: cisco-sa-20131009-asa
http://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20131009-asa
I have a Pix running version 8.0.4 with the following configuration:
inside interface:      192.168.231.254/255.255.255.0
outside interface:     10.100.2.254/255.255.255.0
no nat-control
access-list test permit ip any any log
access-group test in interface outside
access-group test in interface inside
I have a window 2008R2 residing on the Internal interface of the firewall. The domain controller resides on the outside interface of the firewall.
I went ahead and implement the change recommended by Cisco
access-list DNS_INSPECT extended permit udp any any
class-map DNS_INSPECT_CP
   match access-list DNS_INSPECT
policy-map global_policy
   class DNS_INSPECT_CP
     inspect dns preset_dns_map
However, after implement the workaround, my windows 2008R2 machine on the inside network can NOT join with AD on the outside network.
on the log of the firewall I see this:
Oct 31 14:34:09 192.168.231.254 %PIX-4-410001: Dropped UDP DNS request from inside:192.168.231.180/61780 to outside:10.100.2.128/389; label length 132 bytes exceeds protocol limit of 63 bytes
Oct 31 14:34:17 192.168.231.254 %PIX-4-410001: Dropped UDP DNS request from inside:192.168.231.180/61780 to outside:10.100.2.128/389; label length 132 bytes exceeds protocol limit of 63 bytes
I even change the DNS maximum length to 8192 but it still does not work.
I remove the recommendation from the configuration, everything works fine after that.
Anyone knows why?
Thanks in advance

Julio Carvajal wrote:U do not have this command right available at the CLI rightmessage-length maximum client auto
     I do
CiscoPix# sh run policy-map
policy-map type inspect dns preset_dns_map
parameters
message-length maximum 1024
message-length maximum client auto
policy-map global_policy
class inspection_default
inspect ftp
inspect h323 h225
inspect h323 ras
inspect netbios
inspect rsh
inspect rtsp
inspect skinny
inspect esmtp
inspect sunrpc
inspect tftp
inspect sip
inspect xdmcp
inspect sqlnet
inspect dns preset_dns_map
class class_sunrpc_tcp
inspect sunrpc
class DNS_INSPECT_CP
inspect dns preset_dns_map
CiscoPix#
Julio Carvajal wrote: Then clear-local host try one more time and provide the logs.Note:access-list test permit ip any any logaccess-group test in interface outsideaccess-group test in interface insideThat ACL means u have no firewall in place
I am very aware of this. At this point, it does not matter, it just want the firewall to function like a routing device.
It still does NOT work. Here is the log:
Oct 31 17:57:25 192.168.231.254 %PIX-6-106100: access-list test permitted udp inside/192.168.231.180(61982) -> outside/10.100.2.128(53) hit-cnt 1 first hit [0x63a9cac7, 0x0]
Oct 31 17:57:25 192.168.231.254 %PIX-6-106100: access-list test permitted udp inside/192.168.231.180(61983) -> outside/10.100.2.128(389) hit-cnt 1 first hit [0x63a9cac7, 0x0]
Oct 31 17:57:25 192.168.231.254 %PIX-4-410001: Dropped UDP DNS request from inside:192.168.231.180/61983 to outside:10.100.2.128/389; label length 132 bytes exceeds protocol limit of 63 bytes
Oct 31 17:57:32 192.168.231.254 %PIX-4-410001: Dropped UDP DNS request from inside:192.168.231.180/61983 to outside:10.100.2.128/389; label length 132 bytes exceeds protocol limit of 63 bytes
Oct 31 17:57:33 192.168.231.254 %PIX-6-106100: access-list test permitted udp inside/192.168.231.180(50955) -> outside/10.100.2.128(53) hit-cnt 1 first hit [0x63a9cac7, 0x0]

Can not ping internal network from ASA

I can not ping internal computer from ASA. Comp IP address 192.168.187.15, gateway is 192.168.187.14 which is ASA internal interface. I've got an IP Phone connected to the same ASA with Ip address 192.168.185.15 and internal ASA interface 192.168.185.14 and everything works fine. We are doing testing, do not be surprised of configuration.
ASA Version 8.2(1)
hostname ciscoasa
enable password 8Ry2YjIyt7RRXU24 encrypted
passwd 2KFQnbNIdI.2KYOU encrypted
names
dns-guard
interface GigabitEthernet0/0
nameif ouside3
security-level 0
ip address 10.254.17.25 255.255.255.248
interface GigabitEthernet0/1
nameif outside
security-level 0
ip address 10.254.17.9 255.255.255.248
interface GigabitEthernet0/2
nameif Lan
security-level 100
ip address 192.168.185.14 255.255.255.0
interface GigabitEthernet0/3
nameif comp
security-level 50
ip address 192.168.187.14 255.255.255.0
interface Management0/0
nameif management
security-level 100
no ip address
management-only
boot system disk0:/asa821-k8.bin
ftp mode passive
access-list 110 extended permit ip any any
access-list nat extended permit ip any any
access-list allow_ping extended permit icmp any any echo-reply
access-list allow_ping extended permit icmp any any source-quench
access-list allow_ping extended permit icmp any any unreachable
access-list allow_ping extended permit icmp any any time-exceeded
access-list allow_ping extended permit udp any any eq isakmp
access-list allow_ping extended permit esp any any
access-list allow_ping extended permit ah any any
access-list allow_ping extended permit gre any any
access-list nonat extended permit ip any any
access-list nat2 extended permit ip any any
access-list nonat2 extended permit ip any any
pager lines 24
logging asdm informational
mtu ouside3 1500
mtu outside 1500
mtu Lan 1500
mtu comp 1500
mtu management 1500
no failover
icmp unreachable rate-limit 1 burst-size 1
no asdm history enable
arp timeout 14400
global (outside) 1 interface
nat (Lan) 0 access-list nonat
nat (Lan) 1 access-list nat
nat (comp) 0 access-list nonat
nat (comp) 1 access-list nat
access-group allow_ping in interface outside
router eigrp 2008
neighbor 10.254.17.10 interface outside
network 10.254.17.8 255.255.255.248
network 192.168.185.0 255.255.255.0
network 192.168.187.0 255.255.255.0
route outside 0.0.0.0 0.0.0.0 10.254.17.10 1
timeout xlate 3:00:00
timeout conn 1:00:00 half-closed 0:10:00 udp 0:02:00 icmp 0:00:02
timeout sunrpc 0:10:00 h323 0:05:00 h225 1:00:00 mgcp 0:05:00 mgcp-pat 0:05:00
timeout sip 0:30:00 sip_media 0:02:00 sip-invite 0:03:00 sip-disconnect 0:02:00
timeout sip-provisional-media 0:02:00 uauth 0:05:00 absolute
timeout tcp-proxy-reassembly 0:01:00
dynamic-access-policy-record DfltAccessPolicy
http server enable
http 192.168.1.0 255.255.255.0 management
no snmp-server location
no snmp-server contact
snmp-server enable traps snmp authentication linkup linkdown coldstart
crypto ipsec transform-set myset esp-3des esp-md5-hmac
crypto ipsec security-association lifetime seconds 28800
crypto ipsec security-association lifetime kilobytes 4608000
crypto map mymap 10 match address 110
crypto map mymap 10 set peer 10.254.17.10
crypto map mymap 10 set transform-set myset
crypto map mymap interface outside
crypto map mymap2 20 match address 110
crypto map mymap2 20 set peer 10.254.17.18
crypto map mymap2 20 set transform-set myset
crypto map mymap2 interface comp
crypto map mymap3 30 match address 110
crypto map mymap3 30 set peer 10.254.17.26
crypto map mymap3 30 set transform-set myset
crypto map mymap3 interface ouside3
crypto isakmp identity address
crypto isakmp enable ouside3
crypto isakmp enable outside
crypto isakmp enable comp
crypto isakmp policy 10
authentication pre-share
encryption 3des
hash md5
group 2
lifetime 28800
no crypto isakmp nat-traversal
telnet timeout 5
ssh timeout 5
console timeout 0
priority-queue outside
threat-detection basic-threat

This is what I get, looks like ASA does not reply. Why?
ciscoasa# sh capture cpi
5 packets captured
1: 05:20:14.494908 192.168.187.15 > 192.168.187.14: icmp: echo request
2: 05:20:19.526935 192.168.187.15 > 192.168.187.14: icmp: echo request
3: 05:20:25.026320 192.168.187.15 > 192.168.187.14: icmp: echo request
4: 05:20:30.525699 192.168.187.15 > 192.168.187.14: icmp: echo request
5: 05:20:36.025084 192.168.187.15 > 192.168.187.14: icmp: echo request

ASA v9.0.1 and ASDM v7.0.1 released

Looks like v9 is now out...
http://www.cisco.com/en/US/docs/security/asa/asa90/release/notes/asarn90.pdf
Regards Simon
http://www.linksysinfo.org

Thanks for spreading out the good news Simon.
People interested in these two releases can find them here.
ASA 9.0.1 and ASDM 7.0.1
Important points to consider before an upgrade to 9.0:
ASA and ASDM Compatibility
ASA OS
ASDM
ASA Model:
ASA 5505
ASA 5510, 5520, 5540
ASA 5550
ASA 5580
ASA 5512-X, 5515-X, 5525-X, 5545-X, 5555-X
ASA 5585-X
ASASM
ASA 1000V
ASA 9.0(1)
ASDM 7.0(1).
YES
YES
YES
YES
YES
YES
YES
No
Limitations and Restrictions
•Clientless SSL VPN with a self-signed certificate on the ASA—When the ASA uses a self-signed certificate or an untrusted certificate, Firefox 4 and later and Safari are unable to add security exceptions when browsing using an IPv6 address HTTPS URL (FQDN URL is OK): the "Confirm Security Exception" button is disabled. See: https://bugzilla.mozilla.org/show_bug.cgi?id=633001. This caveat affects all SSL connections originating from Firefox or Safari to the ASA (including clientless SSL VPN connections, and ASDM connections). To avoid this caveat, configure a proper certificate for the ASA that is issued by a trusted certificate authority. For Internet Explorer 9 and later, use compatibility mode.
•Citrix Mobile Receiver and accessing Virtual Desktop Infrastructure (VDI):
–CSD is not supported.
–HTTP redirect is not supported.
–Using Citrix Receiver mobile clients to access web interface of Citrix servers is not supported.
–Certificate or smart card authentication is not supported as a means of auto sign-on.
–You must install XML service and configure on XenApp and XenDesktop servers.
–Make sure the ports 443, 1494, 2598, and 80 are open on any intermediate firewalls between the ASA and the XenApp/XenDesktop server.
–The password-expire-in-days notification on tunnel group that is used by VDI is not supported.
•When configuring for IKEv2, for security reasons you should use groups 21, 20, 19, 24, 14, and 5. We do not recommend Diffie Hellman Group1 or Group2. For example, use
crypto ikev2 policy 10
group 21 20 19 24 14 5
As always make sure you are familiar with the upgrade procedure Upgrading the Software.
Important Notes
•Downgrading issues—Upgrading to Version 9.0 includes ACL migration (see the "ACL Migration in Version 9.0" section). Therefore, you cannot downgrade from 9.0 with a migrated configuration. Be sure to make a backup copy of your configuration before you upgrade so you can downgrade using the old configuration if required.
•Per-session PAT disabled when upgrading— Starting in Version 9.0, by default, all TCP PAT traffic and all UDP DNS traffic use per-session PAT (see the xlate per-session command in the command reference). If you upgrade to Version 9.0 from an earlier release, to maintain the existing functionality of multi-session PAT, the per-session PAT feature is disabled during configuration migration. The ASA adds the following deny rules:
xlate per-session deny tcp any4 any4
xlate per-session deny tcp any4 any6
xlate per-session deny tcp any6 any4
xlate per-session deny tcp any6 any6
xlate per-session deny udp any4 any4 eq domain
xlate per-session deny udp any4 any6 eq domain
xlate per-session deny udp any6 any4 eq domain
xlate per-session deny udp any6 any6 eq domain
To enable per-session PAT after you upgrade, enter:
clear configure xlate
The above deny rules are cleared so that only the default permit rules are still in place, thus enabling per-session PAT.
•No Payload Encryption for export—You can purchase some models with No Payload Encryption. For export to some countries, payload encryption cannot be enabled on the Cisco ASA 5500 series. The ASA software senses a No Payload Encryption model, and disables the following features:
–Unified Communications
–VPN
You can still install the Strong Encryption (3DES/AES) license for use with management connections and encrypted route messages for OSPFv3. For example, you can use ASDM HTTPS/SSL, SSHv2, Telnet and SNMPv3. You can also download the dynamic database for the Botnet Traffic Filer (which uses SSL) and redirect traffic to Cloud Web Security.
More information at:
Release Notes for the Cisco ASA Series, 9.0(x)
HTH.
Portu.
Please rate any helpful posts

Guest WLAN and DNS tunneling (IP over DNS with iodine, NSTX, etc)

Hello,
I'm trying to implement guest WLAN with web authentication on the WLC 2504. L3 for guests WLAN is terminated on ASA 5510 (as subinterface).
All works pretty fine. Guests clients are prompted to enter login/password, guests are authenticated against ACS and so on.
But I have a strange idea. How can I prevent unauthorised DNS tunneling from the guest network?
I think that DNS tunneling can be prevented with dns-guard on ASA and dns inspections, e.g. drop dns packets larger then 512 bytes and perform deep inspection againd packets.
Any ideas or advices?

Hello,
I'm trying to implement guest WLAN with web authentication on the WLC 2504. L3 for guests WLAN is terminated on ASA 5510 (as subinterface).
All works pretty fine. Guests clients are prompted to enter login/password, guests are authenticated against ACS and so on.
But I have a strange idea. How can I prevent unauthorised DNS tunneling from the guest network?
I think that DNS tunneling can be prevented with dns-guard on ASA and dns inspections, e.g. drop dns packets larger then 512 bytes and perform deep inspection againd packets.
Any ideas or advices?

ASA UDP Dns reply dropped

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