SF500 48P - Multiple VLANs and Voice VLAN

I have a SF500-48P switch and and have several VLANs on it (over 25 vlans).
Each of these ports shall support also an IPPhone on vlan 4.
I was thinking about using LLDP so I won't have to setup the VLAN manually on each phone.
But when I do here what's happening,
Original configuration:
Port 25:
Vlan 35 untagged
When I plug the phone, the configuration changes to:
Vlan 1 untagged
Vlan 4 tagged
I was expecting the following:
Vlan 35 untagged
Vlan 4 tagged
Note that ports 1-25 have their own individual VLAN and need to be isolated (already done ACL in the router).
I need help,
regards,

What about my other ports that belongs to other Vlans (11-24)?
With the steps you gave me, as soon I connect a Phone, the untagged Vlan becomes 35 for any ports where a phone is connected.
Since I have several Vlans untagged (only 1 per port), I don't want the untagged vlan to be changed by the smartport settings. Is there a way to do that?

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Potential Security Hole with 802.1x and Voice VLANs?

I have been looking at 802.1x and Voice VLANs and I can see what I think is a bit of a security hole.
If a user has no authentication details to gain access via 802.1x - i.e. they have not been given a User ID or the PC doesn't have a certificate etc. If they attach a PC to a switchport that is configured with a Voice VLAN (or disconnect an IP Phone and plug the PC direct into the switchport) they can easily see via packet sniffing the CDP packets that will contain the Voice VLAN ID. They can then easily create a Tagged Virtual NIC (via the NIC utilities or driver etc) with the Voice VLAN 802.1q Tag. Assuming DHCP is enabled for the Voice VLAN they will get assigned an IP address and have access to the IP network. I appreciate the VLAN can be locked down at the Layer-3 level with ACL's so any 'non-voice related' traffic is blocked but in this scenario the user has sucessfully bypassed 802.1x authentication and gain access to the network?
Has anyone done any research into this potential security hole?
Thanks
Andy

Thanks for the reply. To be honest we would normally deploy some or all of the measures you list but these don't around the issue of being able to easily bypass having to authenticate via 802.1x.
As I said I think this is a hole but don't see any solutions at the moment except 802.1x on the IP Phone, although at the moment you can't do this with Voice VLANs?
Andy

Voice Vlan and Native Vlan

Dear all,
I am now reading some information regarding the setup of Voip Phone. It mentioned that the Phone is actually a 3-ports switch:
Port 1: Connect to upstream switch
Port 2: Transfer Phone traffic
Port 3: Connect to a PC
Actually, what should i configure on the upstream switch port? Should it be a trunk port containing both the voice traffic vlan and pc data vlan?
Or something else?
Also, there is a term called 'Voice Vlan', is there any different between 'Voice vlan' and ordinary Vlan ?
Is there any special usage of 'Native' Vlan in implementing Voip?
Thanks.
Br,
aslnet

Thanks.
How about if the PC data should be tagged as another vlan (e.g., Vlan 10)? Then I should change the native vlan to vlan 10?
But from my understanding, Native Vlan should be the same in the whole network, then I need to change the whole network native vlan? If there are different vlans should be assigned to different PCs that behind different VoIP-phone, then how to do it?
From my guessing, is it i can assign individual native vlan (vlan10) on that port (connect to voip-phone), and then keep the switch's uplink port as original native vlan (vlan1).
Therefore, PC data traffic would be untagged when entering from voip to the switch, and then tagged as vlan10 when leaving the switch to other uplink switch, right?
Thanks.

About the Native Vlan and Management Vlan.

I wanted to know that Management vlan and Native vlan can be different vlan id or both should be same vlan id. Why should not be native vlan 1.

The use of a native VLAN is generally frowned upon now as there are some well known security exploits that leverage this untagged VLAN. Cisco often recommends setting the Native VLAN to an unused VLAN in your infrastructure in order to render it useless for attacks.
It is also recommended that you create a separate VLAN for your Management traffic and that this VLAN be tagged (therefore not a Native VLAN).
Native Vlan is the vlan which will be sent untagged even in Trunk links. Consider a Trunk link configured between two switches SWA and SWB, if a system in vlan1 of SWA is sending a frame via SWB, then this frame will be received as untagged by SWB, then switch B decides that the untagged frame is from native vlan 1 and handles accordingly. By default native vlan is 1, this can also be changed as per requirement.
Example: In the below figure if a IP phone and system are connected toa switch port as below, the the Phones will send its frames tagged with vlan 10 where as the frames sent by system will be untagged. So here the the corresponding switch port should be configured as native vlan 20. So that it can recognise and handle the frames from system and IP phone properly.
a
Management vlan is different, it means that this vlan will be used for management purposes like Logging into the switch for management, Monitoring the switch,collecting Syslog ans SNMP traps, etc will be done by management vlan IP. This also by default vlan 1 in cisco. So as Antony said the it is always a Best practice and security measure to not use the default vlan and use custom vlans.
Hope this helps !

802.1x and Voice VLAN

I had read articles on cco, and I believed for the same switch port we can have 802.1x configure and the voice vlan configure. It mean the IP phone is connect to the switch port with 802.1x configured, but the phone will not autheticate, only the workstation connect to phone data port will get authenticate.
I had configured 802.1x and test with notebook logon and able to access the network. Now I would like to test the notebook attached to IP phone data port, and the phone connect to switch port configure with 802.1x. But I failed to add voice vlan commmand. Why ?
interface GigabitEthernet9/48
description temporary port
switchport
switchport access vlan 12
switchport mode access
no ip address
dot1x port-control auto
spanning-tree portfast
CIG01-ENT-SW1(config-if)#switchport voice vlan 14
Command rejected: Gi9/48 is Dot1x enabled port.

Using IEEE 802.1x Authentication with Voice VLAN Ports
A voice VLAN port is a special access port associated with two VLAN identifiers:
?VVID to carry voice traffic to and from the IP phone. The VVID is used to configure the IP phone connected to the port.
?PVID to carry the data traffic to and from the workstation connected to the switch through the IP phone. The PVID is the native VLAN of the port.
In single-host mode, only the IP phone is allowed on the voice VLAN. In multiple-hosts mode, additional clients can send traffic on the voice VLAN after a supplicant is authenticated on the PVID. When multiple-hosts mode is enabled, the supplicant authentication affects both the PVID and the VVID.
A voice VLAN port becomes active when there is a link, and the device MAC address appears after the first CDP message from the IP phone. Cisco IP phones do not relay CDP messages from other devices. As a result, if several Cisco IP phones are connected in series, the switch recognizes only the one directly connected to it. When IEEE 802.1x authentication is enabled on a voice VLAN port, the switch drops packets from unrecognized Cisco IP phones more than one hop away.
When IEEE 802.1x authentication is enabled on a port, you cannot configure a port VLAN that is equal to a voice VLAN.
Waht kind of switch do you have? In 3550 I can configure the port for both vvid and pvid:
interface FastEthernet0/1
switchport access vlan 3
switchport mode access
switchport voice vlan 2
no ip address
dot1x port-control auto
spanning-tree portfast
end
Nevertheless, as the statement above indicates, the port will need to be configured for multi-host in order the PC behind the phone get autehntication:
under the interface configure "dot1x host-mode multi-host"
Nevermind, I just realized that you might have a 5600 running native, checking the configuration guide and realese notes it does not looks like dot1x and vvlan can play together in that platform.

802.1x / dot1x Authentication, including Voice-Vlan and Guest-Vlan

Hello,
i have tried to configure a dot1x based Authentication.
With an single host including guest-vlan, everything works fine.
But i want to use an IP-Phone (wich is every times authenticated) and behind the Phone an Client.
Is there a possible solution? And unfortunately IP-Phones are Avaya-Phones.
i have just tried so...
interface GigabitEthernet0/4
switchport access vlan 121
switchport mode access
switchport voice vlan 200
authentication event fail action authorize vlan 99
authentication event server dead action authorize vlan 121
authentication event server alive action reinitialize
authentication host-mode multi-host
authentication order dot1x
authentication port-control auto
authentication periodic
authentication violation restrict
dot1x pae authenticator
dot1x timeout quiet-period 10
dot1x timeout tx-period 1
spanning-tree portfast
Thanks, for any possible solution!

unfortunately because they are Avaya phones, the easy answer CDP-Bypass fails in this instance. When you plug in the phone, the switch will assume it's the 'single host' for this port, and restrict the port due to the authentication for the phone failing. Maybe you can just hard-code the voice-vlans on each phone, but that could get tedious depending on the amount of phones.
I believe there is a DHCP option you can pass back that indicates the phone should be running on vlan 200, but for this to work you'd also need to set up a pre-auth ACL that would allow DHCP to work in the unauthorized state. I think it's 147 off the top of my head.
Another solution (which isn't what you originally wanted, but it would work) is to just use multi-domain instead of single-host, and authenticate both the phone and the PC. The raduis server should be able to distinguish between what is configured as a phone and what is a host, and will send back the appropriate vlan if configured correctly.
What are using for a radius server?

Cat 3750 with Voice VLAN and Dynamic VLANs

Morning,
Has anyone had any success with configuring a Catalyst 3750 with a Voice VLAN (Cisco phones) and 802.1x dynamic VLANs?
Is a RADIUS server able to provide values to change the native vlan?
Is there a decent tech note knocking about for configuring 'dynamic VLAN assignment through MAC addresses'?
Thanks,

Voice VLAN's don't require trunk ports to be configured (unless you are talkling about 2900XL/3500XL switches). Cisco added the ability to trunk a single 802.1q VLAN down an access port in addition to the access vlan - so in 2950 or above the only config you need is:
interface FastEthernet0/1
switchport
switchport mode access
switchport access vlan 10
switchport voice vlan 100
This is effectively the same as:
interface FastEthernet0/1
switchport
switchport trunk encapsulation dot1q
switchport mode trunk
switchport trunk native vlan 10
switchport trunk allowed vlan 10,100
The only difference is the CDP message with the first config will advertise the Voice VLAN capability and the tag.
With the older 2900XL/3500XL switches you had to configure the interfaces like the second example (plus adding the command switchport voice vlan xx for CDP to inform the IP Phone of the voice vlan).
QoS is not detailed anywhere here and that obviously plays an important role with voice.
In your scenario I am not sure ACS can do what you describe as this will require 802.1x supplicants on the client PC's (I may be wrong here and I do remember someone talking about switches being able to do an 802.1x 'proxy' using the MAC address on behalf of non 802.1x capable devices). This seems to me more of a VMPS application.
Personally I would reconfigure the network each time and charge the occupants a small fee for network setup.....
HTH
Andy

DHCP and voice vlan on Cisco 3560 switch

Greetings,
I'm setting up a Cisco 3560 switch for voice and data comms. I'm looking for documentation with best practice guidelines for the following requirements.
1. Using the Cisco 3560 as a DHCP server - Config examples. Do I need to use different subnets for the voice and data vlans?
2. Layer 2 CoS QoS - I'm connecting Aastra phones as well as notebooks - I've been told that Aastra also makes use of the voice vlan config through LLDP and that Aastra phones supports CDP.
Your assistance will be appreciated.

Hi ,
Cisco recommends that you have a separate vlan for voice and data with different ip subnets for voice and data. You will need to configure the dhcp pool accordingly.
Here is the config guide for setting up IOS DHCP server:
http://www.cisco.com/en/US/docs/ios/12_0t/12_0t1/feature/guide/Easyip2.html
Here is the LAN qos recommendations:
http://www.cisco.com/en/US/docs/voice_ip_comm/cucm/srnd/7x/netstruc.html#wp1044009

VLAN trunking, native vlan and management vlan

Hello all,
In our situation, we have 3 separate vlans: 100 for management vlan and 101 for data and 102 for voice.
We have an uplink which is trunked using .1Q. Our access ports has the data vlan as the native. Based on our design, what should be the native vlan for this uplink trunk? Should it be the management vlan or the data vlan? Thanks for your help.

To answer this question you must remember what the native vlan is. Native is where untagged packets are sent, i.e. packets without a dot1Q tag. It is there mainly for compatibility. On an access port it has no function while normal traffic is not tagged and sent to the vlan that is configured for the port. Traffic for the voice vlan is an exception to this general rule.
Native vlan setting only plays a role on trunk links where most of the traffic carries a tag. As explained, it is then used as the vlan for untagged traffic.
When you do not consider this a security breach, you may configure the data-vlan as native. Use another vlan (why not vlan1?) in the case where you want to isolate this traffic.
I find it good design practice to use the same native vlan throughout the network. This keeps things clear and it's better for anyone who is not completely obsessed with security. The latter kind of people can always find a reason to mess things up, both for themselves and for others;-)
Regards,
Leo

WLC 7.4.110.0 where native vlan and SSID vlan is the same vlan

Hi
We have app. 1500 accespoints in app. 500 locations. WLCs are WiSM2s running 7.4.110.0. The AP are 1131LAPs.In a FlexConnect configuration we use vlan 410 as native vlan and the ssid (LAN) also in vlan 410. This works fine, never had any problems with this.
Now we have started use 1602 APs and the client connection on ssid LAN becomes unstable.
If we configure an different ssid, using vlan 420 and native vlan as 410, everything works fine.
I can't find any recommandations regarding the use of native vlan/ssid vlan
Is there anyone experiencing similar problems? Is this a problem with my configuration or is it a bug wittin 1602 accespoints?
Regards,
Lars Christian

It is the recomended design to put FlexConnect AP mgt into native vlan & user traffic to a tagged vlan.
From the QoS perspective if you want to enforce WLC QoS profile values, you have to tag SSID traffic to a vlan (other than native vlan) & trust CoS on the switch port connected to FlexConnect AP (usually configured as trunk port)
HTH
Rasika
**** Pls rate all useful responses ****

Auth VLAN and Access vlan

When the interface comes up, the CAM puts the user in the AUTH vlan as expected via the set command (vlan 210)
03:09:09: SNMP: Packet received via UDP from 172.31.200.200 on Vlan220
03:09:09: SNMP: Set request, reqid 2144479366, errstat 0, erridx 0
vmVlan.1 = 210
that works OK
Fa0/21, Fa0/22, Fa0/23
210 VLAN0210 active Fa0/1
211 VLAN0211 active
So SNMP RW works OK,
After the user logs in to the network the user should be put back into vlan 220 (according to the port profile settings) but nothig happens, no set command send, no SNMP traffic at all. The user remains in AUTH vlan and the agent loops
I have tried all the settings, role based, initial VLAN as well, to no avail.
Any ideas? What to check for?
Rafal

Have you double checked your settings for mapping ports with the VG setup guide?
http://www.cisco.com/en/US/docs/security/nac/appliance/configuration_guide/412/cas/s_addSrvr.html#wp1089247
Also make sure your OOB port profile is correct and that it switches from auth to access vlan after authentication
http://www.exio.com/en/US/docs/security/nac/appliance/configuration_guide/411/cam/m_oob.html#wp1083087

Users VLAN and Management VLAN

is it possible to separate two VLANs:
one is running for the users VLAN connects to the clients
one is for management purpose.
Is there a sample code available for access points, bridges, and switches?
I am really appreciated that

Hi,
You can configure VLANs on enterprise access points.
What you need to do is configure the access point with its managment IP address, set this as the native vlan and then add the other VLAN or VLANs.
Then on the switch that the access point is connected to you need to configure a trunk port and make sure that the native vlan is the same VLAN you set as native on the access point.
As an example if the Access point has an IP address for managment vlan 20, we set this VLAN as native and then we add the other VLAN or VLANs, and on the switch you configure the port as a trunk port with the same native VLAN 20.
Note, native vlan is the same as untagged vlan. When we confgure a trunk port this will tag all vlans except the native vlan or untagged vlan that needs to be the same between directly connected devices.

What is difference between Default VLAN and Native VLAN?

Answer

Cisco switches always have VLAN 1 as the default VLAN, which is needed for many protocol communication between switches like spanning-tree protocol for instance.
You can't change or even delete the default VLAN, it is mandatory.
The native VLAN is the only VLAN which is not tagged in a trunk, in other words, native VLAN frames are transmitted unchanged.
Per default the native VLAN is VLAN 1 but you can change that:
#show interface Fa0/8 trunk
Port        Mode             Encapsulation Status        Native vlan
Fa0/8       on               802.1q         other         1
(config-if)#switchport trunk native vlan 2
(config-if)#do show interface f0/8 trunk
Port        Mode             Encapsulation Status        Native vlan
Fa0/8       on               802.1q         other         2
The default VLAN is still VLAN 1.
#show vlan id 1
VLAN Name Status    Ports
1    default active    Fa0/8, Gi0/1
HTH
Rolf

802.1x Auth-Fail VLAN and Guest-VLan not available

Hi Pros,
Having an issue with an 881 I have recently acquired. I'm wanting to setup a Virtual Office scenario. Everything is working fine except for 802.1x...
I can get the 881 to authenticate things connected to it, but I don't have the options of guest-vlan or auth-fail vlan.
Idea is if the users takes the router home and someone, either accidentally or on pupose, connects an unauthorized Laptop, they stay off the Corp network but can get to the internet still.
I found this link on Cisco's site:
http://www.cisco.com/en/US/prod/collateral/iosswrel/ps6537/ps6586/ps6660/ps6808/deployment_guide_c07_458259_ns855_Networking_Solutions_White_Paper.html
That link shows them configuring a guest vlan right on the fa0-3 ports of an 881W. I dont have that option on mine. I can only configure 802.1x on the vlan interface. I have 802.1x working, for things that connect to vlan1, but I would like to have a "fallback" setup.
EZVPN_Remote(config-if)#int fa1
EZVPN_Remote(config-if)#dot
EZVPN_Remote(config-if)#dot1?
dot1q
EZVPN_Remote(config-if)#dot1
EZVPN_Remote(config-if)#int vlan1
EZVPN_Remote(config-if)#dot1x ?
default           Configure Dot1x with default values for this port
host-mode         Set the Host mode for 802.1x on this interface
max-reauth-req    Max No.of Reauthentication Attempts
max-req           Max No.of Retries
pae               Set 802.1x interface pae type
port-control      set the port-control value
reauthentication Enable or Disable Reauthentication for this port
timeout           Various Timeouts
Any thoughts why I'm seeing this behavior? Feature-set? IOS Version?
EZVPN_Remote#sh ver
Cisco IOS Software, C880 Software (C880DATA-UNIVERSALK9-M), Version 15.1(2)T4, )
Technical Support: http://www.cisco.com/techsupport
Copyright (c) 1986-2011 by Cisco Systems, Inc.
Compiled Tue 12-Jul-11 21:02 by prod_rel_team
ROM: System Bootstrap, Version 12.4(22r)YB5, RELEASE SOFTWARE (fc1)
EZVPN_Remote uptime is 6 hours, 1 minute
System returned to ROM by reload at 14:53:21 UTC Thu Oct 13 2011
System restarted at 14:52:47 UTC Thu Oct 13 2011
System image file is "flash:c880data-universalk9-mz.151-2.T4.bin"
Last reload type: Normal Reload
Last reload reason: Reload Command
This product contains cryptographic features and is subject to United
States and local country laws governing import, export, transfer and
use. Delivery of Cisco cryptographic products does not imply
third-party authority to import, export, distribute or use encryption.
Importers, exporters, distributors and users are responsible for
compliance with U.S. and local country laws. By using this product you
agree to comply with applicable laws and regulations. If you are unable
to comply with U.S. and local laws, return this product immediately.
A summary of U.S. laws governing Cisco cryptographic products may be found at:
http://www.cisco.com/wwl/export/crypto/tool/stqrg.html
If you require further assistance please contact us by sending email to
[email protected].
Cisco 881 (MPC8300) processor (revision 1.0) with 236544K/25600K bytes of memor.
Processor board ID FTX153482GK
5 FastEthernet interfaces
1 Virtual Private Network (VPN) Module
256K bytes of non-volatile configuration memory.
126000K bytes of ATA CompactFlash (Read/Write)
License Info:
License UDI:
Device#   PID                   SN
*0        CISCO881-SEC-K9       xxxxxxxx
License Information for 'c880-data'
    License Level: advipservices   Type: Permanent
    Next reboot license Level: advipservices
Thanks in advance!

Shamless bump...

Autonymouse AP1121 - Management Vlan and SSID Vlan

Hello,
We are using an ACS server to authenticate wireless users to active directory this works fine. The issue occurs when we try to pull an ip and we can't fomr the dhcp. The vlan we have the SSID on is vlan 10 and the management vlan of the AP is vlan 500. The ip-helper info is correct because wired users on vlan 10 get an ip immedialty. We just can't pull one with the AP. Does anyone know the config for this? Here is my current config, the client authenticate through the ACS 4.2 but pull no ip, the only way for me to manage the ap is to have the native vlan command on there, once i remove it i can't telnet. What is the fix for this? Thanks
current switch port config ap is plugged into.
interface FastEthernet1/0/48
switchport trunk encapsulation dot1q
switchport trunk native vlan 500
switchport mode trunk

Do you have sub interfaces for vlan 10 being brigged through the radio interface?
Example config below...
interface Dot11Radio0.10
description Secure Wireless access
encapsulation dot1Q 10
no ip route-cache
bridge-group 10
bridge-group 10 subscriber-loop-control
bridge-group 10 block-unknown-source
no bridge-group 10 source-learning
no bridge-group 10 unicast-flooding
bridge-group 10 spanning-disabled
interface FastEthernet0.10
encapsulation dot1Q 10
no ip route-cache
bridge-group 10
no bridge-group 10 source-learning
bridge-group 10 spanning-disabled
Also verify that vlan 10 is allowed on the trunk interface of the switch by typing "show int trunk"

SF500 48P - Multiple VLANs and Voice VLAN

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