Mutual Redistribution & Route Tagging
Six routers, two routing domains, two border routers redistributing in both directions. This is the exact shape ENARSI expects you to reason about: not a single redistribution point, but a ring where a route can re-enter the domain it came from.
The problem
Redistribution and route tagging are both configured, but one border router's routes into the EIGRP domain vanished after a change. The route-map still matches and tags correctly, and there's no error in the logs, yet half the redistributed prefixes are simply gone from the EIGRP topology table.
What you'll practice
- Build mutual redistribution between OSPF and EIGRP at two independent border routers
- Use route tagging to mark which domain a redistributed prefix actually originated in
- Recognize the route-feedback risk created by having two redistribution points on a ring
- Diagnose a missing EIGRP seed metric, a classic silent redistribution failure
- Trace a single prefix's tag and route type through both RIBs at each border
The topology
Six Cisco IOS routers in a ring: two pure-OSPF routers, two pure-EIGRP routers, and two dual-protocol border routers that mutually redistribute on both sides, so a prefix from either domain can legitimately reach the other one two different ways.
Topology diagram
Frequently asked
Is this real Cisco IOS or a simulator?
Real Cisco IOS (IOSv) routers, full CLI behavior including EIGRP's composite metric calculation and OSPF's external LSA types, not a simulated subset.
Does this cover the CCNP ENARSI exam topics?
Yes. Mutual redistribution, route tagging, route-maps, and seed metrics are core ENARSI (300-410) blueprint topics, and this is one of the higher-value integrated labs because it combines all of them in one topology.
Ready to run this lab yourself?
No setup, no image sourcing. Book a session or ask for a live demo.