DHCP issue on Yealink phones with HP Switch HP2920

[Crizz]

Hi James,
I even upgraded to 7.73.0.50 for T22P and 29.73.0.50 for T42G.
The LLDP is disabled on the phones. I’m not using VID enable on 50 on the phones yet. The VID is disabled on the phones and some switch ports are untagged on vlan 50 so it should get DHCP. Are getting DHCP ONLY when the phones are connected on the untagged ports on vlan 1.

Hi tsukraw,
The phones should be able to get DHCP when connected on untagged ports on vlan 50 with VID disabled on the phones side. Are getting DHCP only from untagged ports on vlan 1, this vlan 1 is the VLAN where the DHCP serves is sitting. This is not relay / ip helper issue? I don’t think is it as long as the computers are getting DHCP from from vlan 50. I did some wireshark captures on mirrored port and I noticed that the DHCP server is issuing the IP from vlan 50 but the phone cannot receive or accept the knowledge of IP offer.
Another test I did and it works: I allocated a new network card for the DHCP server [IP:20.1.50.240] and I connect it to the untagged port on VLAN 50 on the SW and then I disabled the IP helper address form Vlan 50. It this way the phones managed to get DHCP from VLAN 50. But this is not best practice because I will have many VLANs later on and I need to get DHCP on the phones for troubleshooting. I just want this SW to do the job if it’s a SW issue. Because this SW will be the main SW. later on another 8 SW’s will be uplink connected to this one.

Thank's for replying guys !