Can I configure a /30 transport network and a /29 usable on the same router, it would be a Cisco 891. Comcast used to just give us a /29 usable which we configured on our 891 and everything was great. Now they give us a /30 for transport and a /29 usable. The only way I know how to do it is to have one router with one interface facing the internet with the /30 and one IP address from the /29 on the other interface. Then use a second router with one interface with an IP address from the /29 and point the default route to the first router. My client is not crazy about buying 2 routers for every location. I was able to get Comcast to provision only the /29 but it was a big hassle and there internal ACLs were causing all kinds of problems.