7960 Unable to get DHCP from Roadrunner Cable

[MagnusFox]

Good day all,

I've been testing the CM in my office with great success. The Win2K DHCP server does everything it should, and the phones work great. So I thouhgt it was time to bring a set home and give it a go.

BUT, the set will not get any DHCP info from the cable provider. I contacted RR about this issue and they were less than helpful stating that it would be a Cisco issue as their service does not block DHCP requests to any MAC ranges or device types.

My CM is 3.1 and the firmware on the set would be that version also. I will try a later firmware later, but wanted to get some info from you guys first:

Is there any reason why I cannot receive DHCP info from the cable provider?

Does Cisco have any 'tricks' for setting the set up for this task?

Well, thanks in advance for your input.

 

[AdmanOK]

I've had problems like this (not with a Cisco phone) whereby my cable provider will only allow one IP address to be assigned through my modem. I was trying to swap out routers and because the old router's allocation was still active, the new router didn't receive an IP address. Waited 24 hours for everything to expire and the new router was assigned an address.

 

[BuckWeet]

It won't work anyways, you have to define the TFTP address in the DHCP scope for the callmanagers, and RR won't do that...

BuckWeet

 

[MagnusFox]

I have now put the latest firmware on the set. So, it should have all of the updates from Cisco.

Let me first offer this tip for Buck on the TFTP addressing. One does not need to receive this information from the DHCP server. You can manually define a TFTP server on the set:
Settings > Network Configuration > Alternate TFTP = Yes > TFTP Server 1 = Edit to match.

Now on to the issue of getting any information from the cable provider DHCP server. I left the cable modem off over night and figured that would be enough time for everything to 'reset' but to no avail. I called the cable provider and they told me that leaving the modem unplugged for one minute would reset the MAC table in the modem. The set still refuses to obtain any DHCP information.

If any one has any other 'tricks' please let me know. Seems odd that this Cisco device would fail on a national providers system.

 

[BuckWeet]

Why are you wanting to put it on a public network anyways and why do you have your callmanagers exposed to the entire world.

Did you make sure to buy multiple IP addresses for your cable modem service? Do you have another phone to try? I haven't had it happen with avaya or cisco ip phones yet, but pc's i've had dhcp be denied.. Never looked into real reasons of why..


BuckWeet