I have two routers on my network: the Mikrotik (firewall) and a Cisco (routes between offices).

Although my DHCP server serves up static routes (option 121), some dumb devices ignore option 121 and send all traffic to the default gateway (the Mikrotik firewall).

I would like the Mikrotik firewall to issue an ICMP REDIRECT to these clients when the attempt to access hosts which require routing the the CISCO.

Is this possible? How would I set that up?