Cisco switches with Mitel Phones

[lvlatty]

If you look at the mac address table for an interface with a phone connected the phone is appearing in both vlans (voice and data)
Do you know of a way to stop this happening?

IT_Rm211_SW2#show mac address-table int fa0/9
Mac Address Table
-------------------------------------------

Vlan Mac Address Type Ports
---- ----------- -------- -----
420 0800.0f27.c4d5 DYNAMIC Fa0/9 (Correct VOICE VLAN)
149 0022.680c.dd84 DYNAMIC Fa0/9 (DATA VLAN)
149 0800.0f27.c4d5 DYNAMIC Fa0/9 Why is this hereno arp entry for it and it shouldnt be here anyways..!!

 

[kwbMitel]

One of the typical setups for DHCP discovery has the phone do 2 requests. First a request is made on the Data LAN where it is provided options specifiying the VLAN. The phone then releases the Data IP and rediscovers using tagged packets on the Voice VLAN. The Computer that is plugged into the phone requests an IP on the default LAN.

I'm not very savvy on the inner working of the tables you presented but my interpretation is that the last item is a reflection of the first DHCP discovery by the phone. Eventhough the phone released the IP address for the DHCP server, the cisco kept a record of it regardless.

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Occam's Razor - All things being equal, the simplest solution is the right one.

 

[paterson]

Does your Cisco switch have CDP capable software? If so, then just tag the Mitel VLAN with VOICE. All DHCP requests from the IP phones will sent on the voice VLAN only.

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If you did not take enough time to get it right the first time...

What makes you think that you have time to fix it?

 

[lvlatty]

Yeah, thats exactly what happens, tho after the phone transits into the auxilary vlan it should release the mac entry for the data vlan... after manually clearing the entry in the data vlan, about 60 seconds later it comes back in.

Nortel phones do not do this, im not sure about cisco phones... will check that later.

 

[lvlatty]

cdp running, voice vlan being used (switchport voice vlan xx). still leaves an entry in the data vlan.

 

[paterson]

did you just make this change? If so, then it is my understanding that the MAC tables will take some time to update.

_______________________________________________________________

If you did not take enough time to get it right the first time...

What makes you think that you have time to fix it?

 

[lvlatty]

We have 5000 5212's across our estate and this is the case all over.

 

[Mitel100]

What 3300 software are you running as we had this problem when running release 7 after we upgraded it was then ok.

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There is no 'I' in 'Team'
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[lvlatty]

version 8 over all 60 3300's
So you think its the 3300s? causing this and not the cisco configuration?

 

[IrwinMFletcher]

Wireshark will give you the answer. Otherwise it's like a deaf person trying to figure out which side won a debate....

 

[lvlatty]

wiresharked... cdp seems to be working correctly. can see the request going to the switch, switch is replying with native vlan id (data vlan) and the voice vlan id as well as the usual stuff, ie power consumtion negotiation etc

 

[IrwinMFletcher]

So when you manually clear the entry in the router, you see another message from the set to the router that adds it back in? Can you share the traces?

 

[lvlatty]

Found the fix...

switchport port-security maximum 2
switchport port-security maximum 1 vlan access
switchport port-security maximum 1 vlan voice
switchport port-security
switchport port-security violation restrict

Thanks for you input guys...

;-)