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Ip phones wont boot if CE500s are not connected together.


I am using a windk3 domain and i have the Cisco Unity system for IP telephony.

The unity system is made of 3 computers:

2 Win2k Servers that are connected to 1 Catalyst Express 500 and I assigned the SERVER role to both machines in the smart role configuration.

1 Gateway 2811 that routes my Ip phones network to my windows 2003 domain (192.168.A.XXX to 192.168.B.XXX) I assigned the ROUTER role to that machine on the same switch ( the one with the 2 win2k servers connected to)

The catalyst 2960 have 8 1/10/1000 ethernet ports and the Catalysts Expresses have 2 GB ports and 24 10/100 ports each.

What i would like to do is to connect all the Catalyst 500 switches to the 2960G using the GB ports.

I tried this setup. It was working fine with all the pcs but for some unknown reason, none of my ip phones were able to receive an ip adress from the call manager. Only the phones that were connected to the same switch as the gateway were able to boot properly and receive an IP adress.

I can make it work but only if i connect all my CE500 together using a 10/100 port. Which is not what i want.

If i connect all 4 CE500s to the 2960G and all my CR500 together using a random 10/100 port, I have some critical errors on my CE500's telling me that some ports are blocked due to the Spinning Tree Protocol.

So, is there a way i can connect all 4 CE500's to the 2960 using GB ports and have my Ip phone system up and running?

Thanks for your time.


Re: Ip phones wont boot if CE500s are not connected together.

I think your IP phone DHCP request is not reaching the DHCP server which is configured, usually Callmanager itself in a small network. These requests are broadcasts which will not be send to the next subnet by default. Use IP helper address to reach the DHCP server.

In centralized call processing deployments, if a remote site is configured to use a centralized DHCP server (through the use of a DHCP relay agent such as the IP Helper Address in Cisco IOS) and if connectivity to the central site is severed, IP phones within the branch will not be able to renew their DHCP scope leases. In this situation, branch IP phones are at risk of seeing their DHCP lease expire, thus losing the use of their IP address, which would lead to service interruption