I am in the middle of migrating from an old domain to a new one. At the same time I am implementing 3 new IP subnets for the new domain, while needing to keep the old subnet alive for a while. My current architechure is: ASA5510 firewall - which is the gateway for my old subnet -192.0.0.0/24. No router currently in place and 3 48port layer 2 switches - cisco/linksys variety, New subents's: 10.10.1.0/24, 10.10.3.0/24, 10.10.5.0/24 My ASA cannot handle secondary IP address for the other gateways and I only have the 1 physical port that my old network uses for the LAN gateway. Should I purchase a router and place it in between my switch gear and firewall to act as the gateway for all the new and old subnets? I need the new and old subnets to be able to talk between them. Any ideas?