6513 error message, IP Telepony servers lost communication

[master001]

Hello all,

Recently I got a weird issue .....  IPT servers ( CUCM, Unity and UCCX) lost communication from time to time.

(The logs on those servers show that).

IPT servers are connected to 2 x 6513,  found the following error message on both switches:

%CDP-4-NVLANMISMATCH:Native vlan mismatch detected on port xx

Both 6513 are running CatOS 8.4(5)

Questions:

1. What is the impact of  the error message " %CDP-4-NVLANMISMATCH:Native vlan mismatch detected on port "  ?

2.  What else can I investigate further on switching side? 

Thanks,

master001

[DuncanM2008]

If you've recieved that message it means the ports described in the  error have a Native VLAN mismatch that's been discovered by exchange of  CDP packets.

This happens if either statically or dynamically 802.1Q is configured but the Native (Untagged) VLAN doesn't match on the two ends of the trunk.

Cisco IP Phones typically form an 802.1Q trunk so they can carry the PC traffic and the Voice Traffic over two different Vlan's.

Depending on your configuration all ports by default have the Native VLAN set as 1 unless specifically configured otherwise with the switchport trunk native vlan x command.

It would be worth running the following commands on the ports in the error and posting the output on here:

"show interface x/x/x switchport"

"show interface x/x/x trunk"

where x/x/x is module/slot/port

Also what devices are connected to these ports that are generating CDP Native VLAN mismatch messages?

Thanks,

[master001]

The port on 1x6513  is connected to C2960G

On the other 6513 is connected to CISCO7606

6513 is running CatOS, I am trying to find the command like" show int xxx swithcing/trunk".....

Thanks,

[DuncanM2008]

CatOS should be:

Show trunk mod/port

Show port mod/port status

Try those and post the output.

Thanks,

[master001]

Here is the output.......   seems fine..... Please advice.... Thanks for your time..... .master001

6513B> (enable) show port status X/X

# = 802.1X Authenticated Port Name.

Port  Name                 Status     Vlan       Duplex Speed       Type

----- -------------------- ---------- ---------- ------ ----------- ------------

X/X  NAME                 connected  10          full         100 10/100/1000

6513B> (enable) show trunk X/X     

* - indicates vtp domain mismatch

# - indicates dot1q-all-tagged enabled on the port

$ - indicates non-default dot1q-ethertype value

Port      Mode         Encapsulation  Status        Native vlan

--------  -----------  -------------  ------------  -----------

X/X      auto         dot1q          not-trunking  10

Port      Vlans allowed on trunk

--------  ---------------------------------------------------------------------

X/X      1-4094

Port      Vlans allowed and active in management domain

--------  ---------------------------------------------------------------------

X/X      10

Port      Vlans in spanning tree forwarding state and not pruned

--------  ---------------------------------------------------------------------

X/X      

----------------------------------

6513A> (enable) show port status X/X

# = 802.1X Authenticated Port Name.

Port  Name                 Status     Vlan       Duplex Speed       Type

----- -------------------- ---------- ---------- ------ ----------- ------------

X/X  NAME                  connected  20          full        1000 1000BaseSX

6513A> (enable) show trunk X/X

* - indicates vtp domain mismatch

# - indicates dot1q-all-tagged enabled on the port

$ - indicates non-default dot1q-ethertype value

Port      Mode         Encapsulation  Status        Native vlan

--------  -----------  -------------  ------------  -----------

X/X      auto         negotiate      not-trunking  20

Port      Vlans allowed on trunk

--------  ---------------------------------------------------------------------

X/X      1-4094

Port      Vlans allowed and active in management domain

--------  ---------------------------------------------------------------------

X/X      20

Port      Vlans in spanning tree forwarding state and not pruned

--------  ---------------------------------------------------------------------

X/X