CCIE

EIGRP over DMVPN works beautifully, right up until the moment you realise none of your spokes can reach any of

You have two hubs. You want every spoke to prefer HUB1 and fall back to HUB2 only when HUB1 is

Summarisation is a trade. You send one prefix instead of fifty, which shrinks the routing table and hides internal churn

A branch office with two WAN routers is a good design. Two routers, two circuits, no single point of failure.

OSPF has an unhelpful habit: when you break it, it usually says nothing. An adjacency that should form simply does

Two routes to the same prefix. One has a metric of 20. The other has a metric of 31. Which