I am about to get a deep understanding when you redistribute between protocols and getting stack into loops. So that, I just try to get a loop doing mutual redistribution between EIGRP and OSPF.
If you take a look to the simple scenario with four routers, you will see that when R2 and R3 start doing mutual redistribution a loop is supposed to come up over lo0 and lo7. I mean, these routes are redistribute in R1 simulating EX 170 routes. When you redistribute that routes from R2(EIGRP) into OSPF, the routes gets a better AD (110). Right now there's suboptimal path because all OSPF routers will have to go through R2 in order to reach de loopbacks network. At this point, If I do mutual redistribution over R3 as well, a loop should be coming up........ but It doesn't. I can ping all network device, the route tables are stables and I don't get the loop. Why is it? The loop should be coming up right???
I attach you the route tables so you can check that everything looks like fine and there is no loop.