DHCP Relay over transit-network

Muenz, Michael m.muenz at spam-fetish.org
Tue Dec 30 10:15:45 UTC 2014


Hey list,

I'm not an expert regarding dhcp relay, but I unterstand the principle 
and got it running when DHCP server is at the other interface of the 
firewall.
Now I have 2 networks, connected at 2 firewalls which have a transit 
network:

LAN1: 10.0.0.0/24 - FIREWALL1 --- 10.5.5.0 transit --- FIREWALL2 - LAN2: 
10.0.1.0/24

In both networks (LAN1, LAN2) is a DHCP server and has to be the 
failover for the other one, configured via delayed replies.
When I start dhcp-relay on FW1 with "/usr/local/dhcp/sbin/dhcrelay -i 
eth1 10.0.1.100", I can see the packet on FW2 going to 10.0.1.100, but 
with the source ip 10.5.5.1.
The dhcp-server on LAN2 doesn't reply to this one.

Can dhcrelay work with this setup in general or isn't this possible?

Searching the web only shows me results when the dhcp server is 
connected to the same firewall on another interface.

Thanks
Michael







More information about the dhcp-users mailing list