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Beginner

Cisco 7941/7961 not honoring DHCP options

I've had to migrate a few of our 7941/7961 phones and have run into a small, but significant issue.  The phones are connecting to the DHCP server, which returns a response with options 66 and 150 to route to a specific Tftp server.  The phones pick up their appropriate IP address correctly, but never attempt to contact the Tftp server for the firmware.  I can connect a pc to the network, which receives an ip on the same network and it can also establish connections to the Tftp server, so I'm thinking it's something special about the phones that's creating my headache.  I've sniffed the DHCP packets and can confirm that options 66 and 150 are correctly populated in the response.

 

Any ideas?

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VIP Collaborator

Re: Cisco 7941/7961 not honoring DHCP options

Hi,

1. Have you tried factory resetting the phones?

2. Have you tried restarting TFTP service?

3. Are phones correctly configured in the server?

4. Do you have any access list between voice network and TFTP server?

 

 

Please rate helpful posts and if applicable mark "Accept as a Solution".
Thanks, Vaijanath S.
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Beginner

Re: Cisco 7941/7961 not honoring DHCP options

1. Have you tried factory resetting the phones?  Yes.  They are actually locked in the update boot cycle because they are not downloading the firmware from the TFTP service.

2. Have you tried restarting TFTP service?  Yes, this did not help.  The phones aren't actually even trying to initiate contact with it, according to the logs.

3. Are phones correctly configured in the server?   This might be where my ignorance is, but does the phone configuration matter (i.e. do the phones try to get a configuration) before they have the firmware from the TFTP server?  The quick answer is one is configured, but one is not, however, both phones are correctly obtaining an IP address from the DHCP server.

4. Do you have any access list between voice network and TFTP server?  I'll have to apologize here, as well.  I don't understand what you're asking in this question.

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VIP Rising star

Re: Cisco 7941/7961 not honoring DHCP options

Regarding .4

Try to setup a pc with the same IP address of a phone (voice network) and then from this PC try to ping the IP address of your TFTP server to identify if this is reachable from the voice vlan. If this is reachable, then you can try from dos to telnet TCP/8089 and UDP/69 to check if these ports are blocked from an access-list.

G

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Cisco Employee

Re: Cisco 7941/7961 not honoring DHCP options

Try to Erase ITL and CTL files from phones.

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Contributor

Re: Cisco 7941/7961 not honoring DHCP options

I think factory reset would have already done that.  What I'd do if the phones are "stuck in the update boot cycle" is to try and connect one to a separate network with a local TFTP server and force out the phone load version that you want.  Sometimes it can help to let them boot up using a local power brick if you have one available, that stops it even trying TFTP or anything, then once it's booted you can erase its settings.

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