2.5 Routing Loop Prevention

I have a alternate solution and I'm looking for feedback:

2.5 Routing Loop Prevention

  • Ensure that the RIP routes redistributed on R6 are never passed from OSPF and then back into EIGRP on R3 and SW2.
  • Use a method that will automatically take into account any new routes redistributed into EIGRP from RIP on R6.
  • You should not configure more than two devices for this task.


This creates a loop as R3 and SW2 are both connected to EIGRP and OSPF domains.

My solution for R3 and SW2 was:

route-map BLOCK-EIGRP-EX-MAP deny 10
 match tag 90
route-map BLOCK-EIGRP-EX-MAP permit 20

router ospf 1
 distribute-list route-map BLOCK-EIGRP-EX-MAP in
 redistribute eigrp 100 subnets tag 90

router eigrp 100
 redist ospf 1 metric 10000 1 255 1 1500

The SG solution has only one of the 2 routers still having the orginal external EIGRP routes where mine has both routers having the orginal external EIGRP routes by denying the routes in to the router via OSPF (lower metric).



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