3com 5500g-EI and Avaya IP Phone and DHCP

[Hboogie]

I have an avaya 4620sw IP Phone connecting to a 3com 5500G-EI switch.

I have setup a vlan for the Voice network with a corresponding DHCP Scope.

Voice Network = 10.1.1.1 - Vlan 3

Data Network is: 192.168.1.1 - Vlan 1 ( Native )

The port that the phone connects to is setup as a hybrid port and is a
TAGGED memeber of vlan 3 and an UNTAGGED member of vlan 1. The PVID of the
port is set to 3.

The DHCP server is located in the native VLAN 1.

The avaya IP phone has a switch built-in which i use to connect a laptop.
However when i connect a laptop to the switch it gets an IP from the DHCP
scope reserved for VLAN 3 ( 10.x.x.x.) -- i really want the laptop to get an
IP from the native vlan 1( 192.168.1.x) and the phone to get the IP of vlan
3 ( 10.x.x.x)




how can i get this done ?

 

[IRudebwoy]

Can't be done. Unless the built-in switch has enough smarts to identify the data and assign it correctly to the appropriate VLAN.

I've tried something similar with 3Com NBX phones but I couldn't get the data traffic off the voice VLAN. I've since concluded the ports in back of the phones are a convienence and should not be used permanantly. Eventually they go out and voice quality suffers (at least with the NBX system). I'm not too sure about Avaya's system.

It might work if the built-in switch can be configured like a managed switch. If it's anything like the switch built into the 3Com NBX phones the scenario you presented is un-supportable.

I hope this sheds some light.

 

[Hboogie]

thanks for the reply. however, if you are indicating that the limitation on the avaya phone's switch -- then avaya begs to differ.

Take a look at the thread i started that leads me to believe that what i'm trying to accomplish should work.

http://tinyurl.com/n6sbh

 

[IRudebwoy]

From what I've read, you should be pulling IP's from the DHCP server's Default VLAN1 pool first. Once the phones encounter the [tt]option 176 L2Q=1,L2QVLAN=3[/tt] defined the scope they should release the IP in VLAN1 and redefine themselves in VLAN3 and get a correct IP and config.

Am I correct so far? Is that working?

If the the above holds true all DHCP requests should be fullfilled by the VLAN1 scope. Only if the host (phone or computer) encounters option 176 should they "pop" into VLAN3. Assuming the computer doesn't know how to handle option 176 it should stay in VLAN1. Unless there is a mis-config in the DHCP service. Look at your DHCP logs to try and decipher what DHCP transactions are taking place. I don't know where to look in M$ Windows for that info, sorry.

I'm assuming the switches and phone equipment are working as expected. As the Avaya member stated. Start with DHCP.

BTW, no shots at Avaya intended. I haven't used their equipment before so I didn't know what to expect.

Have Fun!

 

[Hboogie]

Hey -

You are exactly right about your summation of what is "suppose" to happen.

I am using the windows 2000 DHCP iteration and look to upgrae to the windows 2003 this weekend. Hopefully it is DHCP that is giving me the problema nd hopefully i'll be smiling come monday.

Thanks,

 

[marksgt]

The problem stems from the fact that you set the PVID to vlan 3. The PVID is the native vlan. The native vlan doesn't tag. Workstation NICs generally do not understand tags and hence need to be on the native vlan. Try changing the port to a trunk and leaving the PVID of trunk link to vlan 1. I've done this exact scenario multiple times with 3Com NBXs and it works like a charm. This assumes that the Avaya phones can understand and tag packets onto VLAN 3. Do a display vlan all and look at which vlans are tagging and which aren't.

Mark Sargent
sargent@getadvanced.net

http://www.getadvanced.net