Interesting fun tonight with static routes. I started working the INE labs for routing and realized some fun stuff. One, I forgot about proxy ARP. I forgot that when you set a static route out a multi-access broadcast interface such as Ethernet, it is better to set the next-hop as the IP address and not the exiting interface. With proxy ARP and going to a router that is on the same segment, it is no problem since the far-end router will respond. Without proxy ARP, the far-end router won't respond and the local router won't know what to do. Way to beat this is to add a static ARP entry on the local router. Ah, the little things.
Next fun thing was when using the exit interface on a static route is good and not good with DMVPN. Didn't realize that if you specify the tunnel interface on the hub router, it won't work because it can't query itself as the NHS to find the NBMA to send the inner traffic. The spokes are good like this since they can query the hub/NHS. How to fix this you ask? Well there are two ways. Specify the next hop IP address in the static route or create NHRP maps on the hub tunnel interface that matches the inner and outer address. That is good to know because I can see this being a ticket in the troubleshooting section.
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