Configure ISC DHCP server “routers”

Question

My challenge is trying to find a conditional way to change the order of the default gateways used in "option routers" parameters. Perhaps on receiving a DHCPDISCOVER message.

So the first client requestiong a DHCP address will receive 10.1.1.1 10.1.1.2 as "option routers" and the next request will send 10.1.1.2 10.1.1.1 as "option routers".

Basically inversing the order of the default gateways.

I need this in order to achieve some load balancing and failover in the same time, using only DHCP server for this.

I am currently looking at "dhcp-eval" options which seems like being a set of options geard towards such customizations but it is difficult to understand where to start.

Does anyone had to do something similar and if yes, could you share the code/setup that was used for scenario?

Thank you!

Answer 1

It seems like I need to answer my own question.

I found a way to achieve the above setup although it is achieved with 2 DHCP servers workign in a failover / load balancing scenario. It turns out thet the ISC DHCP server have such options startuing with v3 onwards. It achieves what I wanted, although in a slightly different way.

http://www.madboa.com/geek/dhcp-failover/

http://www.ipamworldwide.com/dhcp-failover-a-load-balancing/dhcp-load-balancing.html

Nevertheless, I would still love to hear opinions about my initial solution so any ideas are welcome.

Cheers!