DHCP and voip cisco 7910 settings

Posted on 2006-04-13
Medium Priority
Last Modified: 2008-02-01
I have dhcp set up on the network. I need to set dhcp reservations for cisco voip phones. The reservations work, however, the router information needs to be inputted as well in order to reach the tftp server. Are there any options in the scope I can use to do this for the "default router 1" setting on the phone. I do have router in already for pcs but it wont push to the vopi phone either.
Question by:jbell72
  • 3
LVL 32

Accepted Solution

rsivanandan earned 1000 total points
ID: 16447087
Ideally you should have them both in 2 Vlans. But anyways, don't you have default router configured in your DHCP scope? or is it that the voip phone won't accept it? What is happening?

Can you explain a bit more on your setup?


Author Comment

ID: 16448071
Yes, I have the default router set up in my scope, all pcs take the router setting no problem. The voip phone takes all settings but the router info is left blank on the phone.

Author Comment

ID: 16448085
I am just wondering if the phone is rejecting it or just cant read it or something not sure.

Author Comment

ID: 16551390
I added 4 ips from each scope as interfaces on the router. They then were passed down to the phone via dhcp options. The ip of the router/gareway had to in the same range as the ip of the phone.

Expert Comment

ID: 16566287
There's some sample config from a working environment below. You'll also need to set up two DHCP scopes on your server, one for voice and one for data. Include the usual scope options such as DNS servers and Default Gateway.  You'll also need to configure the TFTP Server option (I'm assuming you're using a Windows DHCP server.) Full instructions on Configuring Windows 2000 DHCP Server for Cisco CallManager are at: http://www.cisco.com/en/US/products/sw/voicesw/ps556/products_tech_note09186a00800942f4.shtml


interface FastEthernet0/0
 no ip address
interface FastEthernet0/0.1
 encapsulation dot1Q 23
description Data_VLAN_Default_Gateway
 ip address
ip helper-address (!DHCP SERVER)
interface FastEthernet0/0.2
 encapsulation dot1Q 13
description Voice_VLAN_Default_Gateway
 ip address
 ip helper-address (!DHCP SERVER)


interface FastEthernet0/5
 description To_Router
 switchport trunk encapsulation dot1q
 switchport mode trunk
interface FastEthernet0/18
 description To_Phone_and_PC
 switchport access vlan 23
 switchport trunk encapsulation dot1q
 switchport mode trunk
 switchport voice vlan 13
 spanning-tree portfast
vlan 23
name Data_VLAN
vlan 13
name Voice_VLAN

Hope this helps,


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