DNS lookup behaviour of cisco devices

Hi All,
Does anyone know how routers and ASA's deal with dns lookups for hostnames in their configuration?
For instance, an NTP server (0.pool.ntp.org), or a hostname in a VPN tunnel configuration.
I get the impression that there is only a 1 time resolve happening.
Can anyone confirm this and if this is the case, does anyone know how to modify this behaviour....
Thanks in advance.

Hi,
Cisco routers can be set up as proxy-dns but with a lot of limitations but ASA can't so on the ASA you must enter static host commands which stay indefinitely.
I don' t know if it's possible to tune the cache timeout and what is the default value.
Here is the link descibing the caveats for IOS:
http://nil.si/ipcorner/RouterDNS/
Regards.
Alain.

Similar Messages

DNS Lookup for DHCP-assigned devices

Hi!
I expected that my router would be able to act as a DNS server to allow machines on my network to look up the IP addresses of other machines on my network, given that every machine on my network gets its IP address from the router via DHCP - but the router doesn't appear to be capable of that.
The router in question is a Linksys E2000 device, and it has the latest firmware revision installed (1.0.03 build 2Sep 7, 2010).
So, the questions I have are:
1. Can this router act as a DNS server?
2. If the answer to (1) is "yes", then how should it be configured?
Mike

Name resolution in LANs in Windows happens usually based on broadcasts in a workgroup or homegroup and that's generally the best way to do it. Some routers add DHCP entries to the DNS proxy but you can read about a lot of issues with that either, in particular if the DNS proxy information gets incorrect somehow and the DNS resolution is configured with precedence to LAN name resolution...
I would suggest you make sure your LAN name resolution is working properly.

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

DNS Lookup Timeout Problems with Cisco SA520w

Hello,
We are trying to configure our new Cisco SA520w with our Internet connection.
As soon as we replace our existing Linksys RV042 with the Cisco SA520w, we find that DNS lookups start to take longer and longer to resovle. For example, an nslookup against yahoo.com will timeout, or take 10-12 seconds. Web browser requests simillarly take 30-45 seconds to resolve.
We've tried using both Google's and OpenDNS servers, as well as our ISP's nameservers. In all cases, the long DNS resolution takes place.
At first we thought that the firewall was misconfigured. However, we removed all firwall rules, and continued to experience the problem.
We've tried checking and unchecking the DNSProxy checkbox, but this doesn't seem to have any noticeable impact.
Does anyone have any idea about which setting impact DNS looksups, or what else we might try to troubleshoot this issue?
Thanks,
Chris

Regarding the question on 5-10 days for product support to become active, I followed up with the CA team and received the following, which is good for All partners to know...
Below is a description of the primary cause of delays in contract registration.
Contract registration takes 24-48hrs. Delays are generally caused by the Reseller/Partner who doesn't provide the product serial numbers to Cisco when they purchase the service. The contract cannot be registered until the Reseller or the Disti provides the serial numbers to Cisco via SMS3 (or B2B). In cases where Disti doesn't have a mechanism to collect the serial number before the product is shipped, or in cases of drop-ship, the Distis often have to track down their Resellers to get the serial numbers to Cisco.
There is a new program being discussed (drawing board now, so not available today) which will to allow the end-user to register the contract themselves, thus eliminating the need for the Disti or the Reseller to collect the serial number an input it into SMS3.
But in any case (now or later), when a customer calls in for support, if their contract has not yet been registered, the SBSC can work with the Global Entitlement Team to look-up the contract via the PO or SO number and complete the registration so service can be provided.
Hope this helps...
Steve

DNS lookups to VPN hijacked by WRVS4400N (fw v1.1.13)?

I have a WRVS4400N on the latest firmware offered by Cisco. After a whole run of problems with previous firmware, this one seems to be almost perfect except for this odd issue I've been encountering now (that I hadn't encountered on previous firmware).
It seems as though DNS lookups through the WRVS4400N are being redirected through a different DNS from the one set on the client (presumably, the router is taking all outbound UDP DNS queries and 'fixing' them to direct at the WAN DNS).
I've verified this by using the 'host' command in UNIX (where 192.168.2.140 is the DNS server on the remote VPN network):
1) Using a standard UDP DNS lookup from the LAN (192.168.1.0) to the VPN
$ host test.intranetdomain.com 192.168.2.140
Using domain server:
Name: 192.168.2.140
Address: 192.168.2.140#53
Aliases:
Host test.intranetdomain.com not found: 3(NXDOMAIN)
2) Using a TCP DNS lookup from the LAN to the VPN
$ host -T test.intranetdomain.com 192.168.2.140
Using domain server:
Name: 192.168.2.140
Address: 192.168.2.140#53
Aliases:
test.intranetdomain.com has address 192.168.2.5
3) Using a standard DNS lookup to an unassigned IP on the local LAN
$ host test.intranetdomain.com 192.168.1.250
;; connection timed out; no servers could be reached
4) Using a standard DNS lookup to a nonsense internet IP
$ host test.intranetdomain.com 254.254.254.254
Using domain server:
Name: 254.254.254.254
Address: 254.254.254.254#53
Aliases:
Host test.intranetdomain.com not found: 3(NXDOMAIN)
These tests are pretty revealing:
Test #1 shows a standard DNS query as a client system would typically perform it. It's querying the server and the server is returning that the address I've asked it for is not known. This is unexpected behaviour as the server at that IP address definitely knows test.intranetdomain.com exists.
Test #2 shows that if queried using TCP instead of UDP, the DNS does know test.intranet.domain.com exists. So, is the host command in Test #1 actually talking to my server? It doesn't seem so.
Test #3 is a demonstration of the expected response when host cannot talk to a remote DNS or that server doesn't exist. In this case, I'm using host to query an IP on my LAN that doesn't have anything on it. This should be the response I get when I try to query a nonexistent server on the internet as well.
Test #4 shows that in spite of the expected responses in Test #3, the WRVS4400N doesn't act as expected. It shows the same type of response we saw in Test #1 even when querying non-existent IPs.
In summary, the tests show that the WRVS4400N in firmware 1.1.13 is capturing all standard UDP DNS queries regardless of the IP they're directed to, and forwarding them to another DNS (I assume the WAN DNS).
This seems like it may have been thrown in as an unmentioned 'feature' and is behaviour I might expect from a 'home' routing solution but not a small office solution such as this. My company VPN requires DNS to be resolved by our servers inside the office network so this is not acceptible.
Configuration Details:
WAN: DHCP, dynamic IP, dyndns
LAN: defaults for everything, static DNS set to use servers across the VPN
VPN: IPSec tunnel to remote network 192.168.2.x
IPS: Disabled
Firewall: Defaults
Any assistance or commentary from someone in-the-know would be appreciated. Also, any comments from those also experiencing variations on this issue.
Message Edited by litui on 03-10-2009 06:25 PM

I've experienced the same DNS hijacking unable to use OpenDNS features unless I set the outside interface to static which is really DHCP by my cable provider. Of course, this is only a temporary work-around. Linksys/Cisco could allow for selectable DNS on the outside interface to resolve this problem, but they won't even look at a code change... unless EVERYONE complains. I requested this almost a year ago via a TAC case & their reaction was development almost never update unless they get many requests.

LMS 4.2.2 ipsla http operation without DNS Lookup Time

Hi,
i´ve setup a add hoc device (webserver) and created a http operation with following options (see image 1) This operation polls the device every 10secs. So far so good. However, in the monitor graphic chart i do not see the DNS Lookup Time (image 2). What´s wrong with this setup?
Thank you,

the patch for BugID CSCtz29665 is released here on CCO:
"http://www.cisco.com/cisco/software/release.html?mdfid=284259296&flowid=31102&softwareid=280775103&os=Windows%20CE%202.11&release=CSCtz29665_4.2.2&relind=AVAILABLE&rellifecycle=&reltype=latest"
I do not know whey they opend a new section for Windows CE 2.11, - but on CCO you have to follow this path to find it:
Downloads Home > Products > Network Management and Automation > Routing and Switching Management > Network Management Solutions > Cisco Prime LAN Management Solution > Cisco Prime LAN Management Solution 4.2 > LMS Patches > Windows CE 2.11-CSCtz29665_4.2.2

WLC 5508 and WPA/WPA2 causes client DNS lookups to fail

Hi all, we just recently received a brand new 5508 with 6.0.199.4 firmware. We currently have three LAP-1250s that associate just fine to the WLC.
For testing purposes only, we enabled WPA2 with both types of encryption TKIP and AES with an ASCII PSK.   The clients are able to connect, authenticate and get an IP address from our local (same subnet) DHCP server. They also get the DNS info from our DHCP server.   However, the problem is that they are not able to do any DNS lookups.   I haven't run wireshark yet to confirm, but it sounds very familiar to this problem: https://supportforums.cisco.com/message/3202369
I've even had clients use nslookup with both of my DNS servers and they are not able to resolve. I'm not sure if the request or the reply is being blocked/dropped, but I can find out tomorrow.
Now the strange part - if I turn off WLAN security altogether, it works!   That's right, I just disable L2 security for the WLAN and re-connect the clients and they are able to do full DNS lookups.
AND - if I leave L2 security configured (WPA2 with PSK), and enable L3 Passthrough security - the clients get to the auth web page, click the "accept" button and are then able to do full DNS lookups too.
What could be the problem here?   There's nothing I see configured for the L2 or L3 security settings that could be the culprit. We're using default (from Cisco) configuration, so there's no ACLs configured or anything like that to block DNS.
Another strange thing here which may or not be related - during initial configuration the setup asked for a virtual IP - so I gave it one - 1.1.2.2.   Now when I do an ipconfig /all on the client, I see this 1.1.2.2 address listed as the DHCP server. Why is this?   It's definitely getting an IP address and DNS info from the correct DHCP server, so not sure why this is showing up.
Thanks, Matt

/* Style Definitions */
table.MsoNormalTable
{mso-style-name:"Table Normal";
mso-tstyle-rowband-size:0;
mso-tstyle-colband-size:0;
mso-style-noshow:yes;
mso-style-priority:99;
mso-style-qformat:yes;
mso-style-parent:"";
mso-padding-alt:0in 5.4pt 0in 5.4pt;
mso-para-margin-top:0in;
mso-para-margin-right:0in;
mso-para-margin-bottom:10.0pt;
mso-para-margin-left:0in;
line-height:115%;
mso-pagination:widow-orphan;
font-size:11.0pt;
font-family:"Calibri","sans-serif";
mso-ascii-font-family:Calibri;
mso-ascii-theme-font:minor-latin;
mso-fareast-font-family:"Times New Roman";
mso-fareast-theme-font:minor-fareast;
mso-hansi-font-family:Calibri;
mso-hansi-theme-font:minor-latin;
mso-bidi-font-family:"Times New Roman";
mso-bidi-theme-font:minor-bidi;}
Hi Matt,
Just wanted to jump in, and also mention it may be worth attempting to disable the fastpath feature on the 5508, and test your failing client again. You may be hitting CSCti34667.
debug fastpath cfgtool --fc.disable
This command can be run via Telnet/SSH. Please keep in mind that fastpath will automatically re-enable periodically, so we recommend disabling every 10 minutes as a workaround for any known fastpath issues. You can do so by running the following Macro in TeraTerm:
:mainloop
   sendln "debug fastpath cfgtool --fc.disable"
   pause 600
goto mainloop
If you find that disabling fastpath resolves your concern, you can reach out to TAC for an Escalation Image with the fix for this one.
Best,
Drew

Change hostname on Cisco devices that are in production

I'm new to Cisco devices and to my current job as network analyst. Mostly in an attempt to establish consistency and to ease identification, I'd like to change the hostname of most of our Cisco switches and routers. However, I don't want to create any other problems.
If I proceed with the hostname change on our Cisco devices that are in production, would there be any negative impact that I may expect?
Thanks in advance!

Hi
Couple of things spring to mind
1) DNS resolution. How do you resolve the hostnames for your routers/switches now ?. if you do it via DNS then you need to update it to reflect the new name.
2) Any scripts etc. that you may use to automate taks on your network may need updating although if they use DNS to resolev just see 1
3) SSH. If you are using SSH to manage your routers/switches and you change the hostname the ssh key will become invalid. You will need to regenerate the key.
HTH
Jon

Local site blocked - DNS lookup failed

Hitting our webpage from the inside is blocked; the policy trace shows Request blocked: Details: DNS Lookup fails
the local webpage is in the Custom URL Catagory- Allow group...
This fails when leaving the www off the front. www.site.com works but site.com fails...
.site.com and site.com are in the custom URL catagory in an 'allow' group
this is also in the bypass filter

A large amount of sites in the world are unable to resolve domains that do not have www in the front. The easiest example is NASA. Go to nasa.gov and it does not work. www.nasa.gov does work. This is due to the admins configuration. However like chris mentioned I would confirm that your DNS is opperating correctly.
P.S. The nasa test might or might not work. Some browsers automatically change the nasa.gov to www.nasa.gov
Christian Rahl
Customer Support Engineer
Cisco Web Content Security Appliance
Cisco Technical Assistance Center RTP

WSA error DNS lookup failed

hi,
When i try to download a file from let say xyz.com i am not able to do so.Policy trace show below result
User Information
User Name: r5893
Group Membership: NBKDOM\r5893, NBKDOM\Limit_Login_Single, NBKDOM\MMS_Access Group, NBKDOM\Screen Saver, NBKDOM\Domain Users, NBKDOM\MMSGroup, NBKDOM\Purchasing&GS-Kuwait, NBKDOM\AllUsers, NBKDOM\Outlook Users, NBKDOM\Administration-Kuwai, NBKDOM\BOUsers, NBKDOM\MYNBKUSERS, NBKDOM\Purchasing Requests - Administration, NBKDOM\EVGROUP001
User-Agent: Mozilla/5.0 (compatible; MSIE 9.0; Windows NT 6.1; WOW64; Trident/5.0)
Custom URL Category: Allow sites
Policy Match
Cisco IronPort Data Security policy: None
Decryption policy: None
Routing policy: Global Routing Policy
Identity policy: Users
Access policy: NBK_Users
Final Result
Request blocked
Details: DNS lookup failed
Trace session complete

Hi Asim,
I would investigate the DNS by establishing an SSH session to the M1 interface. Do an 'nslookup xyz.com' and see if it resolves. If it does not resolve, you may want to check your DNS server.
-Vance

Syslog server for Monitoring Cisco devices

I am looking for Syslog server to log all logs from Cisco devices. We have more than 800 cisco devices. Can anyone tell me what syslog server should i use to log these files.
Thank you.

Has anyone used the Cisco recommendation of Buliding Scalable Syslog Solutions?
http://www.cisco.com/en/US/technologies/collateral/tk869/tk769/white_paper_c11-557812.html#wp9000318
I used this in another organaztion and we were very successful, we currenlty use Netcool that feeds from a syslog and we get several non-actionable alarms and it's very time consuming for 13,000 devices. I would only like to alert on 0-5 Cisco Syslog messages. Below is the response from my Netcool Administrator (What are your thoughts?):
From my Netcool Administrator:
Regarding, using the Cisco syslog severity for alert control, I feel that is not the best way to control the work in Netcool.
1. -- Cisco is not consistent with the use of this value.
    Examples:
        In this case the important message is the lower severity alert: I would consider the BGP-3-NOTIFICATION of a 6 level of Informational
        Aug 4 03:10:01 rtgara02r01m04-lb0.us.bank-dns.com 001458: Aug 4 03:10:01: %BGP-5-ADJCHANGE: neighbor 10.93.69.106 Down BGP Notification sent
        Aug 4 03:10:02 rtgara02r01m04-lb0.us.bank-dns.com 001459: Aug 4 03:10:01: %BGP-3-NOTIFICATION: sent to neighbor 10.93.69.106 4/0 (hold time expired) 0 bytes
        This one is near the top level of serverity per Cisco but not all that severe in reality, further this syslog has a bug where the threshold is not even exceeded
        %ENVMON-1-CPU_WARNING_OVERTEMP: Critical Warning: CPU temperature 107C exceeds threshold 110C. Please resolve system cooling immediately to prevent system damage
        This one is reporting a standard condition:
        %ILPOWER-5-POWER_GRANTED: Interface Fa0/24: Power granted
        Here is an example of a 1 where the voice group says that nothing is wrong:
        Aug 4 13:08:42 rtgcaa75u01-01.sw.us.bank-dns.com 047489: Aug 4 11:08:41: %IVR-1-APP_PARALLEL_INVALID_LIST: Call terminated. Huntgroup \'1\' does not contain enough valid SIP end-points to proceed with a parallel call.

DNS lookup failing on Macbook with Fios

Hello all
I've had Verizon Fios for over a year and had no problems connecting wirelessly to my MacBook. Out of the blue today, both my MacBook and my brother's began to have issues accessing the internet. Every attempt would yield the same response:
This webpage is not available
The server at google.com can't be found, because the DNS lookup failed. DNS is the web service that translates a website's name to its Internet address. This error is most often caused by having no connection to the Internet or a misconfigured network. It can also be caused by an unresponsive DNS server or a firewall preventing Google Chrome from accessing the network.
Here are some suggestions:
Reload this web page later.
Check your Internet connection. Reboot any routers, modems, or other network devices you may be using.
Check your DNS settings. Contact your network administrator if you're not sure what this means.
Try disabling network prediction by following these steps: Go to Wrench menu > Preferences > Under the Hood and deselect "Predict network actions to improve page load performance." If this does not resolve the issue, we recommend selecting this option again for improved performance.
Try adding Google Chrome as a permitted program in your firewall or antivirus software's settings. If it is already a permitted program, try deleting it from the list of permitted programs and adding it again.
If you use a proxy server, check your proxy settings or check with your network administrator to make sure the proxy server is working.
If you don't believe you should be using a proxy server, try the following steps: Go to Applications > System Preferences > Network > Advanced > Proxies and deselect any proxies that have been selected.
Error 105 (net::ERR_NAME_NOT_RESOLVED): Unable to resolve the server's DNS address.
I called Verizon for support, and while their reset of my internet has allowed me to connect directly from a ethernet cord from my router, I'm still getting the same result on any attempts to connect via wi-fi. Since Verizon decided it was a Mac issue and not a Verizon issue at this point, they pointed me in the direction of applecare, but I don't have the money to spend right now on a support call.
It seems that the router is connecting to the internet, and I can connect through ethernet, but their is a problem with the wireless communication between my computer and the router. Any suggestions?

That is a different issue. Most likely, your university IT has misconfigured their network and only tested it on Windows where little details like TCP/IP subnets aren't even checked. This sounds pretty typical for university IT. Unfortunately, you will have zero luck getting them to fix the problem because they don't support MACS.
First of all, your question is pretty important and shouldn't be tucked inside a Verizon FiOS thread where no one will see it. I suggest starting a new question so that people looking for this topic in the future can find the answer.
I am familiar with this problem. It is an IT configuration problem. I just rolled my own hack for it. I should probably try to improve my hack since obviously other people are experiencing the same problem.
Before I get started. Why are you even looking? What is the exact problem that you are having? My problem was specific to VPNs but your issue seems even more basic than that. What, exactly, does or does not happen to cause you to search for a fix?
In the Terminal, run the command "scutil list". How many DNS entries are listed? What are they? You should have one that says "State:/Network/Global/DNS". Type "show State:/Network/Global/DNS". What does it return? Are these the DNS servers that you added?
Let me know the respones to the above and then I can craft a command that will correct and possibly override those servers properly.

E4200 - DNS Lookup Is Extremely Slow

Pros: Sometimes, it times out. I don't know what's wrong. I'm thinking of returning the unit. I'm using Comcast and everything was super fast with my trusty old Linksys WRT-54GL. Nothing good about this unit. Cons: DNS Lookup Is Extremely Slow. Sometimes, it times out. I don't know what's wrong. I'm thinking of returning the unit. I'm using Comcast and everything was super fast with my trusty old Linksys WRT-54GL

If I relate your issue then the above mentioned solution justifies the troubleshooting steps to be taken, however, in addition to that I would also like to suggest you to try and install your Linksys E4200 router using the Cisco Connect Software just in case, if you are not using it....
Installation disc that came along with your router would help you in installing this router using the Cisco Connect Software, using which you can expect this router to offer you best throughput with both wired and wireless connectivity.....
To set up your router using the Cisco Connect Software, you can use:
http://www6.nohold.net/Cisco2/ukp.aspx?pid=80&app=vw&vw=1&login=1&json=1&docid=e30f926604334d5386685...
Also, try re-installing your router using the Cisco Connect Software, and it should help your cause....Just in case required, you can use the above mentioned troubleshooting steps.....

Airport Extreme DNS lookups stalling; creating page load delays

As of the last few days, maybe a week, I've noticed my Airport Extreme (the most recent version, tall squarish one) has been getting slow at random times. Nothing on the network locally would be causing it. The slowness appears to be in DNS lookups... you know, that bit the browser does behind the scenes to turn google.com into 173.194.37.4. At first I thought it was just a slow DNS server setup we had configured in the Airport (8.8.8.8 and 8.8.4.4) but I've switched them to something that performs a bit better (if you can call 12 ms vs 14 ms lookups, "better", lol).
The issue manifests itself over wired and wireless computers connected to the Airport.
We also have a airport express (the short squarish one, newest model) that is setup for the purposes of creating a roaming network. Another thought was maybe it flipped over to try to issue IPs, so I looked to ensure it was on the proper settings, and it is.
The software on the airport management client (in windows) and the airport extreme + express are updated. I have already tried to reset them from scratch and reconfigure, to no avail.
Interestingly, what leads me to believe it's related to DNS Lookups is, when I am experiencing the issue, if I download a file - say a really large file, just to test, the download speed is as it should be from my ISP. But if you try to browse to any ole page, apple.com, google.com, arstechnica.com, or sites that are generally really quick, like msn.com or wsj.com, it would be faster to tap it out in stone.
We're experiencing this on a interesting set of devices, Windows 7 and 8 computers, an iPad, a Android tablet, android phone, iPhone, and a Windows phone.
Does anyone have any suggestions? I've found a few older threads with similar issues, but they are outdated and/or seem to chalk it up to a bug and Apple needs to fix via update. This is just super frustrating.

Hi tbonecopper,
If you feel you are having DNS-related slowness on your Airport Extreme, you may find the following article helpful (it is written with a computer focus, but the same principles should also apply at the router):
Non-responsive DNS server or invalid DNS configuration can cause long delay before webpages load
http://support.apple.com/kb/ts2296
Regards,
- Brenden

Unable to open 2 9509 switches at the same time in Cisco Device Manager

Dear Friends,
There are a pair of MDS 9509 switches whose management addresses are 172.16.2.197 and 172.16.2.198.
When we try to manage these Devices through Cisco device manager, the first device opens up without any problem, but when the second 9509 is opened in Cisco Device Manager, it fails giving the following error message:
"Open udp transport failed: Address already in use: Cannot bind"
To get around this issue, if we close the first interface to the 9509 switch, then we are able to open up the second 9509 in Device Manager.
We have this problem only in Cisco device manager. If we open one switch in Cisco device manager and the other switch in Cisco Fabric Manager, it works.
Also, we can telnet to both the devices successfully at a time.
The device manager in use is 4.1.
Please find enclosed the sh version outputs for your kind reference.
Can you please help me understand the cause of this issue?
Thanks a lot
Gautam

Is it always the same MDS that fails to open, or can you open either one first, and then the second one poses the problem (no matter which one is second)?
Can you try from a second work station and see if you can open DM to both switched at the same time? I suspect the address it is complaining about is the local workstation IP, not the MDS IP.
If you open the FM map, then you click on the MDS ICONs, can you open DM to both MDS?
- Mike

DNS lookup behaviour of cisco devices

Similar Messages

Maybe you are looking for