EIGRP Unequal-Cost Load Balancing with Variance

Bundle lab

Build a 3-router EIGRP domain where R1 reaches R3’s loopback over two paths (direct and via R2). You will tune interface delay so the indirect path becomes the successor and the direct path remains a feasible successor, then enable variance to install both unequal-cost paths in R1’s routing table. Two Alpine hosts validate end-to-end reachability while router show commands confirm unequal-cost load sharing.

Learning objectives

• Form EIGRP adjacencies across three point-to-point /30 transits with a consistent AS and classless operation
• Advertise specific connected networks using precise EIGRP network wildcard statements and passive host-facing interfaces
• Manipulate EIGRP metrics via interface delay to select a desired successor and maintain a feasible successor
• Enable unequal-cost load balancing with variance and verify multiple next-hops and traffic-share counts in the routing table
• Use EIGRP operational commands to validate neighbors, topology, feasible condition, and route installation

Troubleshooting focus

• AS number mismatch or missing network statement prevents adjacencies from forming
• Incorrect wildcard mask includes/excludes the wrong interface, hiding routes
• Forgetting no auto-summary causes classful boundaries and unexpected routes
• Delay not applied on the intended interface prevents the indirect path from being the successor
• Variance configured without a feasible successor does not install additional paths