AVAYA 9600 Phones won't get DHCP from Cisco 3750 Switch

[smithtrans1]

Wanted to see if anyone could help with our avaya 9600 phones not getting a dhcp address from our Cisco 3750V2 switch. So far this is what I have for the scope.

ip dhcp pool AVAYA

network 172.23.240.0 255.255.240.0

default-router 172.23.240.1

option 242 ascii "MCIPADD=172.23.240.10,MCPORT=1719,HTTPSRVR=172.23.240.10,L2Q=1,L2QVLAN=240"

ip dhcp excluded-address 172.23.240.1 172.23.240.10

lease 90

That is our scope with excluding IP's 240.1 - .10,  and a lease of 90 days, now my question is and I have seen a lot of responses, what do I need to have under the switch ports? I have tried this configuration and it won't hand it out to the phone. Our data vlan is default at 1 and our voice vlan is 240.

interface FastEthernet1/0/2

switchport access vlan 1

switchport trunk encapsulation dot1q

switchport trunk native vlan 1

switchport trunk allowed vlan 1,240

switchport mode trunk

switchport voice vlan 240

[John Blakley]

The Avaya phones, unless they've completely changed, don't understand cdp, so I don't believe the voice vlan setting will work. I've not actually tested it, although I really should. Anyway, the easiest port config you need is:

interface FastEthernet1/0/2

switchport trunk encapsulation dot1q

switchport trunk allowed vlan 1,240

switchport mode trunk

The phone will be told what to tag the traffic by it's 242 string. The option string also needs to be on the data vlan though. When the phone boots, it will boot on the native vlan and pull a data address. If you don't have the 242 string on the data side, it won't know to tag it's traffic and move to your voice vlan.

Your data option string would look like:

option 242 ascii "L2Q=1,L2QVLAN=240"

HTH,
John

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[smithtrans1]

Thanks John,

Still having issues with getting an IP after setting this up like you wrote. Would having an IP Base image on this have any affect on the DHCP not being served? The image is c3750-ipbasek9-mz.150-2.SE2.bin

Thanks for any help,

Marc

[John Blakley]

Not really. Can you post both scopes (data and voice) from the switch and a switchport config?

HTH,
John

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[Umesh Shetty]

Hi,

I've seen this issue with Avaya phones, the way we've implemented it in our setup is similar to what John suggested. The option 242 in the data Vlan we have is option 242 ascii "L2QVLAN=240 Static =3".  The phones after picking up the vlan tag in the data vlan must start tagging their frames as vlan 240 and try to get an IP in that vlan. May I ask you a few questions here.

1> Do the phones get an IP from the data vlan properly ?

2> If it does means that it is not able to pickup the vlan 240 tag from the data vlan option 242.

What I'd observed is when a new phone with a default firmware is connected it doesn't pickup the vlan tag and remains in the data vlan. What you can try is manually set the vlan to 240 and connect the phone. The phone must now get an IP from the vlan 240 directly. Once it contacts to httpserver for the firmware and gets updated , then try to clear the manual settings and try to boot. This time the phone will pickup the vlan tag in the data vlan and swtch over to the voice vlan. I've seem this happen twice, so if you could try this out.

HTH

Regards

Umesh