Cisco 7925G wifi not getting IP adddress

[JustinM]

I am deploying my first Meraki switch(MS120-8FP) and ap(MR33) at a new branch location. I am having issue with Cisco 7925G phones getting ip addresses via dhcp from a Windows DHCP server at the main office. The phones work without issue on our aging Cisco APs at the main location and presumably other offices that I have these same phones deployed at. Wired phones get IP address from DHCP on same VLAN and a windows laptop also got an IP via DHCP when connecting to the voice SSID on the Meraki AP.

Packet captures dont seem to show any thing but an ARP "Who has 6.49.30.115? Tell 0.0.0.0"

This was all Meraki support was able to see.

I have ran through some of the Meraki guides but see no change. Actually some contradict each other in some spots.

Anyone have any tips for getting these phones working?

[PhilipDAth]

So this is a WiFi connected phone?

Is the SSID configured for bridge mode?

What is doing the DHCP forwarding?

Have you tried a manual release/renew of the IP address on the phone?

[PhilipDAth]

Can a normal notebook connect to the same SSID as being used by the phone and get an IP address ok?

[JustinM]

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@PhilipDAth wrote:

Can a normal notebook connect to the same SSID as being used by the phone and get an IP address ok? Yes I have connected a laptop to voice ssid. It does get a ip via dhcp.

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[JustinM]

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@PhilipDAth wrote:

So this is a WiFi connected phone? Yes the 7925G is a WiFi phone.

Is the SSID configured for bridge mode? Yes it is

What is doing the DHCP forwarding? Ip helper address on the vlan at the cisco router. Meraki recognises dhcp server from the wired phone and laptop I tested.

Have you tried a manual release/renew of the IP address on the phone? Well I have power cycled the phone multiple times that should do it.

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[PhilipDAth]

Negative, power cycling a 7900 series phone does not release the DHCP config.  You need to do it manually from the phone interface or factory reset the phone.

[PhilipDAth]

Until you can see the phone making a DHCP request in a packet capture the phone is not working as required.

[JustinM]

Hmm weird that it works then at my other locations that are using Cisco APs.

Anyone using these phone and have them working?

[Gumby]

I've got a single 7925G deployed with no issues.  DHCP across a VLAN with ip-helper on the router.  No special config at all.

Now if we are talking 8821's and 802.11r roaming that is another story....

[JustinM · Accepted solution]

Yesterday I noticed the Meraki switch reporting crc errors on the AP Switch port.

I quick google found https://community.meraki.com/t5/Wireless-LAN/MR33-CRC-align-errors/td-p/2162

Last night I pushed out the Stable Release Candidate to my MR33.

Today without making any changes the 7925G wifi phone it has registered with Call Manager.

Something in MR 25.9 seems to have fixed that issue.