DHCP and Windows 2003 problem

[razillian]

A few weeks back we upgraded our last server from Win2K to 2003 Server. Aside from being our PDC and what not, it serves as our DHCP server for both PCs and our 4600 IP phones. Since that time we've run into a little problem that I can't find any documentation on.

Whenever we have to reset a phone, it goes through its normal cycle, seems to pull down an IP address, then sits at "Finding Router". Standard option 003 for the router is still set (no DHCP changes were made other then upgrading the server to 2003).

In the past if something like this happened, we manually put in all the IP address information, let the phone boot up, then reset it once it was running. It would pull from the DHCP server and be happy. Since we upgraded to 2003, that no longer works, so as phones have to be reset, we are stuck assigning a static IP address.

We have an Avaya 8500 with around 120 phones (mixture of 4610 and 4620). The phones are on VLAN 241 while the PCs are on VLAN 1. The phones do seem to get MOST of the info from the DHCP server (for example they will switch over to VLAN 241 on reboot), it is just that they die with the router portion. Our new phone vendor mentioned something about configuration differences between Win2K and 2003 that is listed on the Avaya website, but that document apparently does not exist.

Any help is greatly appreciated. Below is the DHCP scope stuff.

003 Router 192.168.241.10
066 Boot Server Host Name 192.168.1.241
176 IP_Phones MCIPADD=192.168.241.243,MCPORT=1719,L2QVLAN=241,L2Q=1,VLANTEST=0

 

[YeOldPhoneGuy]

What type of data switches are the phones connected to?

Me

 

[razillian]

The phones and computers all run through a mixture of Dell 6024, Dell 5212 and Dell 3324 switches. Everything worked fine until the DHCP server was upgraded to Windows 2003. But that could just be a coincidence.

 

[YeOldPhoneGuy]

Does the Server have an address in the data vlan and voice vlan? I have experienced this exact issue. It was a windows issue. The broadcast for an address was seen locally by the windows server and it would only send a data address. Resolved it by setting up a tcp helper on the voice vlan pointing it back to the data scope.

Me

 

[warcomlee]

We experienced a similar issue - DHCP Conflict Errors once moving to 2003. After various traces we eventually established that Avaya phones only seem to accept 2 IP addresses from a DHCP and then fail if those addresses are not valid. The server issues an address; the phone braodcasts to see if it's in use; gets a reply; advises the server; requests another; server issues same address (because it thinks it spare); phone repeats process, then errors on 3rd attempt.
We solved it by enabling server side conflict detection on the DHCP server. This forced the server to check the IP address being issued BEFORE offering it to the phone.
It looks like the rejection of the IP address back from the phone is not recognised by the server so it keeps issuing the same address.