We have recently installed a new VoIP phone system, I got two Vlans configured on all the HP switches (they are the only ones that are POE) with them configed as vlan1 (data) being untagged and 200 (voice) as tagged. I also have the last two ports on the switch etherchanneled to a cisco switch. I have two DHCP servesr, one for the voice Vlan and one for the data.
So I have two issues, it was brought to my attention by our helpdesk guy that once in a while when he images a machine and it comes up, that it gets an IP address from the Voice vlan, but he can do a / release and /renew and all is fine, gets a new IP from the data dhcp and we don't see it again. The only catch to this is, that if the machine is off line for a couple weeks and comes back, it may get a DHCP address from the voice vlan. The only thing that I can think of is if during that time the person is gone the address lease expires on the Data DHCP server and somehow it is lost.
My other issue is this. While trying to solve the previous issue I decided to force the DHCP server on a tagged only port (force it to be on Vlan 200 only). When i do that nothing can talk to it and vice versa. I even tried putting another machine on the same switch forcing it too to be on Vlan 200 and they are unable to see each other.