Problems with IP phones going back to VLAN 0

[phonegoober]

hello all,

we had a major problem this past weekend where some maintenace was done on one of our Cisco Switches and it was taking down, hence we had problems with IP Phones.
We VLAN tag for voice. once the switch maint was done, the phones did not boot back up correctly, they kept wanting to goto VLAN 0 even though we have option 176 defined what VLAN the subnet should be tagged as.

only way we were able to get the phones to come back up was to manually program the correct vlan in on the phone. After a couple hundred phones, it was a long time before we got the call center back up.

need to know how i can fix this:
Through option 176?
Through our Cisco switch config?
What does VLANSEP and VLAN TEST in option 176 really do?

thanks

 

[randyb19]

I had the same issue in the past.

Set your VLANTEST to zero in option 176. Any other value will tell the phones to default back to VLAN 0 after x number of seconds. By making it 'VLANTEST=0' the phones will not default back, but rather keep their vlan setting even after a reboot. Sometimes the phones can be powered back on before the switch is even ready to pass data, so by locking the phones into their vlan, they'll just wait for communications to come up.

 

[phonegoober]

Thanks randyb19.

What does the VLANSEP really do. Does it work with PHY2, if there is a value associated with it?

 

[randyb19]

My understanding of VLANSEP is if you are also tagging packets for priority from a PC connected to the phone(0=disable; 1=enable). This ensures VLAN separation on the same wire. You would use the the PHY2VLAN and PHY2PRIO commands along with it. Check out the 4600 LAN Admin Guide from the Avaya support website if you are curious.

 

[gphone]

We've had the same issue before. What is option 176 that you are referring to?

 

[dj42Avaya]

Option 176 is for the 46xx ip phones and provides the call server, tftp server and vlan separation information if you are running separate voice and data vlans. Some people run everything on one and use COS. basically, option 176 supplies all the information you would have to put in the phone if you statically programmed it. You vlan separation can also be done by adding both the voice and data address ranges to the ip-network-map and assigning them to the voice vlan on that page. What will happen is the phone will always register with the server on the data vlan. Once it sees the network-map, it will look back to the DHCP server for it's correct address for that vlan... It works both ways...