I am having a problem trying to setup separate VLAN's for the voice and PC on a 504G (firmware 7.4.4) connected to a Cisco SLM248P switch (firmware 18.104.22.168). Basically with VLAN's turned off the phone receives its IP and configuration via DHCP without any problem. However whenever I setup the phone as such it stops working.
Enable VLAN: Yes
VLAN ID: 1
CDP: No (tried Yes too)
The switch port that the phone is connected to is a member of VLAN1 Untagged and VLAN2 Tagged.
After setting up this configuration, the PC connected into the phone can reach other devices on VLAN2 without any issue. The phone however will not pull its IP/config from the DHCP server. I see the DHCPDISCOVER and DHCPOFFER coming from the MAC address of the phone but I never see a DHCPREQUEST or DHCPACK meaning it has received the IP. It just keeps looping thru discover and offer requests over and over. I have also tried running the phone on an older firmware version with the same results.
I also have a SPA525G setup in the exact same manner as the 504 and it works fine.
Unfortunately, I am in a situation where I have a number of offices where there is only one network drop so I need to get this working. Any advice or suggestions would be much appreciated.
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Attached are a couple wireshark captures. It has some extraneous info in it but you should be able to filter that out. The mac address of the phone is C4:7D:4F:06:53:00. Let me know if this capture does not include what you need.
ext110-novlan.pcap is when there is no vlan setup and the phone receives it's IP address
ext110-vlan.pcap is when the vlan is setup and the phone does not receive it's IP address
Some additional information. 1) I tried multiple 504G phones and all exhibited the same behavior. 2) If I set the phones IP address statically and have the vlan setup it is still not pingable.