Does ip helper address work for VLAN SVIs on a 3750 switch?

[gerryobrien]

Hi. Has anyone managed to get ip helper address to forward DHCP broadcasts from one SVI VLAN interface to another on a 3750 switch?

[Georg Pauwen]

Hello,

putting the ip helper address on one SVI pointing to an IP address off another SVI works, what exactly does your config look like, can you post it ?

Regards,

GP

[gerryobrien]

Here is the config for the 3750 switch. We think we are doing everything by the book but no DHCP requests are getting out of VLAN 5 to the helper address in VLAN 1. Are there additional DHCP server/replay settings that must be on. Thanks for any help

[gerryobrien]

Does anybody know what is the interaction between the DHCP relay service and the ip helper address command on a 3750 switch? Are they independent fo each other or does that DHCP services need to be set up for the ip helper address command to work?

[Georg Pauwen]

Hello,

which physical interface is your DHCP server with IP address 134.226.32.57 connected to ? You have no trunk ports, only access ports, none of which is assigned to VLAN 1.

Regards,

Georg

[gerryobrien]

Hi. The DHCP server 134.226.32.57 is attached through a switch on giga 1/0/1. I thought all unassigned switchports were defaulted to VLAN1. Anyway, I've added giga 1/0/1 to VLAN 1 but the assignment doesn't show up so I assume its the default. The 134.226.32 subnet is handled by the primary address of VLAN1

Gerry