I have some questions about EIGRP redistributing a null route. I understand the concept of the null routes with route summarization but I am confused on the behavior in this case.
The goal was to not spit out 10.x.x.x stuff to the ISP router if it wasn't in the routing table. The problem was it redistributed that route into the routing table and told everyone to send 10.0.0.0/8 stuff to him who deposited it in the bit bucket. Changing the EIGRP network to 10.2.x.x 0.0.255.255 corrected my problem. My thought is it looked at the Null 0 interface as directly connected and had 10.0.0.0 255.0.0.0 as its IP address or something like that. With that, it put the 10.0.0.0/8 network in the routing table and dumped it to Null0 when it got there.
- router connected to internet using gre/ipsec vpn tunnels to 4 other routers
- default route set to isp router
- internal LAN set to 10.2.x.1 255.255.254.0
- eigrp set to network 10.0.0.0
- null route created for 10.0.0.0 0.0.0.255 null 0
- no route redistribution set
Here is an upstream routers routing table when network 10.0.0.0 was in place. Yes, it does do some redistribution but this route was put there by the router with the null route.
Router1#sh ip route 10.0.0.0
Routing entry for 10.0.0.0/8, 636 known subnets
Attached (117 connections)
Variably subnetted with 6 masks
Redistributing via eigrp 1
D10.0.0.0/8 [90/12902400] via 10.2.x.173, 00:29:00, Tunnel192
Can someone enlighten me to why this happened? Why would it redistribute that?
Thanks for your help.