Switches, Hubs, and Modems
cancel
Showing results for 
Search instead for 
Did you mean: 

DHCP relay between VLANs

Andrei Raileanu
Occasional Contributor

DHCP relay between VLANs

Hello,

I am trying to enable dhcp relay between 2 VLANs. The DHCP server is in VLAN 1210 and the client in VLAN 1216.

The hosts are connected on tagged interfaces (trunk ports). The routing is done by an HSR6602. Here is the pertinent config snippet:

dhcp relay server-group 0 ip 10.12.10.11
#
udp-helper enable

#

.....

#
interface GigabitEthernet0/0/0.1210
vlan-type dot1q vid 1210
ip address 10.12.10.3 255.255.255.0
vrrp version 3
vrrp dot1q vid 1210
vrrp vrid 121 virtual-ip 10.12.10.1
vrrp vrid 121 priority 10
vrrp vrid 121 track interface GigabitEthernet0/0/1
#
interface GigabitEthernet0/0/0.1216
vlan-type dot1q vid 1216
ip address 10.12.16.3 255.255.255.0
vrrp version 3
vrrp dot1q vid 10
vrrp vrid 126 virtual-ip 10.12.16.1
vrrp vrid 126 priority 10
vrrp vrid 126 track interface GigabitEthernet0/0/1
dhcp select relay
dhcp relay server-select 0
#

Routing seems to be working fine between these VLANs, but there are no DHCP requests forwarded to my DHCP server from VLAN 1216.

What did I miss?

1 REPLY
Andrei Raileanu
Occasional Contributor

SOLVED Re: DHCP relay between VLANs

It seems that the dhcp needs to be enabled on the router:

dhcp enable

I do not think that udp helper is doing anything here.