can't get address from DHCP...

I have a UC520 and have plugged a 7960 into fa0/1/0 but it won't get an address from DHCP. Here's what I have:

UC520#sh run int fa0/1/0
Building configuration...

Current configuration : 110 bytes
!
interface FastEthernet0/1/0
switchport access vlan 2
switchport voice vlan 3
spanning-tree portfast
end

UC520#sh run | se dhcp
ip dhcp excluded-address 10.10.3.0 10.10.3.20
ip dhcp pool VOICE
network 10.10.3.0 255.255.255.128
default-router 10.10.3.1
dns-server 10.10.3.1
option 150 ip 10.10.3.2

UC520#sh run int fa0/0.3
Building configuration...

Current configuration : 105 bytes
!
interface FastEthernet0/0.3
encapsulation dot1Q 3 native
ip address 10.10.3.2 255.255.255.128
end

I know the DHCP server is working because I have a 2960 connected to the WAN port of the UC520 and any phone plugged into the 2960 gets an IP address fine. Any ideas?

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Comments

Fish!

This ought to take care of it:

no interface FastEthernet0/0.3

interface vlan3
ip address 10.10.3.2 255.255.255.128
no shut

interface FastEthernet0/1/0
switchport mode access

IP address 10.10.3.2 needs to be on interface vlan3 not on a subinterface on interface FastEthernet0/0. Also I think you need 'switchport mode access' on the switch port - otherwise it defaults to switchport mode dynamic desirable - a trunk - and the access+voice commands don't take effect until the mode is access.

EDIT: Oh, wait, I just noticed you have a switch hanging off of int f0/0.

OK, move the 2960 switch to one of the switch ports on the UC520 and create a trunk.

-OR-

Leave the 2960 on f0/0 and do IRB.

bridging irb
bridge 1 route ip

int fa0/0.3
bridge-group 1
no ip address

int vlan3
bridge-group 1
no ip address

int bvi1
ip address 10.10.3.2 255.255.255.128

Much more yucky, but it works.

snickered

I don't care what they say about you. You're a good man! I moved the trunk over to fa0/1/8(the "expansion" port) and removed fa0/0.3... worked like a charm. Thanks a lot. I don't even know what IRB is so I won't even attempt that method.

APA

your original config would have worked.....

should have encapsulation dot1q 3 without the native command on the fa port....

You obviously had that port hooked up to the 2960 as a trunk right??? So the native vlans would have been matching meaning all the 3 traffic would be untagged...... remember the native vlan traffic is always untagged with dot1q unless you tell it to be tagged...

Hence plugging a phone into the 2960 was working....