Hi,

I have finally got Lync phone edition devices into a separate VLAN.  All working ok, except when logging in they pause for about 5-10 seconds with error "Registrar FQDN cannot be found".  They then sign in and work perfectly.  Option 120 is setup on DHCP and was working fine when they were in the same VLAN as the server.  I am using an IP Helper to allow the phones to get their DHCP settings for our DHCP server.

Our Lync Servers (FE and Edge Internal interface) are in VLAN 10 with subnet 192.168.10.0/24.
Our DHCP is yet to be moved into our server VLAN and is currently in VLAN 0 10.81.108.0/22.
Our Lync Phone devices are in VLAN 20 192.168.20.0/24.

When I run DHCPUtil.exe -emulateclient on another computer in the 10.81.108.0/22 subnet, I get the following result:

Result: Success
DHCP Server : 10.81.108.11
SIP Server FQDN :
Certificate Provisioning Service URL : https://SR-LC-01.OPG.INTERNAL:443/CertProv/CertProvisioningService.svc

It doesn't appear to be receiving the option 120 information from our DHCP server.  But this is setup as follows:

The other DHCP options required for the phones are being pulled down successfully, but this one appears to be failing.  Please help!

Many Thanks,

Andrew

I have had a similar issue in the past and it turned out to be the IP Helper, managed to narrow it down by running DHCPUtil in the same VLAN as the phones. Then tried a phone in the same VLAN as the servers.  That isolated it for me before.

I have exactly this same problem with Registrar FQDN cannot be found for about 30 sec, and when phone finally signed in I have about 5-10 seconds time out before proper call but only in new Vlan, in old vlan works fine

How haveyou resolve this issue