Enhanced Interior Gateway Routing Protocol, Cisco's hybrid distance-vector IGP. Articles tagged EIGRP cover the DUAL algorithm, composite metric and K values, stub routing, adjacency requirements, and Cisco IOS XE configuration.
EIGRP for IPv6 is a separate protocol instance with no network statement and link-local next hops. You walk the classic interface-based config on IOS XE 17.18, see real adjacencies and routes, and clear up the shutdown gotcha.
Full EIGRP build on the Cisco ASA captured live from an ASAv 9.24, from working adjacency to the number-one neighbor failure that produces no error, no log, just an empty neighbor table.
Migrate a live network from EIGRP to OSPF without dropping a packet: run both protocols side by side, then flip administrative distance one command at a time. The ships in the night technique with real lab output.
Two-point redistribution is where networks go to die. This article builds the classic CCIE failure for real in a CML lab, shows a route being re-injected into the protocol it came from, and then fixes it with the exact output at each step.
Tunnels up, neighbors up, routes missing: split horizon breaks EIGRP over DMVPN's mGRE cloud. Covers split horizon and next-hop-self, dual-hub design, and the dual-homed loop, with real CML output.
Offset lists add metric to specific routes on a specific interface in a specific direction, without touching delay for everyone else. See them steer spokes to HUB1 in a dual-hub DMVPN on IOS XE, with exact before and after metrics.
EIGRP summarization shrinks routing tables but hides detail. A leak map lets you advertise the summary and still punch through specific prefixes that must stay visible. Shown working on Cisco IOS XE with real DMVPN lab output.
EIGRP Site of Origin stamps routes with an extended community so dual-homed WAN sites do not learn their own prefixes back. Covers what SoO does, how it is configured, and what we actually found trying it on IOS XE.
Redistribution fails three ways: routes that never arrive, routes that echo back and loop, and routes that arrive but take the long way. All three captured on CML with IOS XE 17.18.2, including the EIGRP external at AD 170 that loses to OSPF's 110 while the shorter direct path sits unused in the...
Default hello timers take tens of seconds to notice a dead neighbor. This post configures BFD on Cisco IOS XE and races it against OSPF defaults: 34 seconds without BFD, 0.58 seconds with it, captured live with a stopwatch.
Two border routers redistributing between the same domains give every prefix a feedback path. Build the forwarding loop live on Cisco IOS XE, capture it happening, then fix it with route tags the way production networks do.
Route redistribution end to end on Cisco IOS XE: how seed metrics work, what each protocol demands before accepting foreign routes, and what the routing table looks like at every stage. Every capture comes from a live CML lab.