Dynamic Multipoint VPN, the hub-and-spoke overlay that builds spoke-to-spoke tunnels on demand. Articles tagged DMVPN cover NHRP, mGRE, the three phases, and routing over the overlay.
Five MPLS L3VPN and DMVPN ticket scenarios, each isolated layer by layer: IGP, LDP, MP-BGP, NHRP, IPsec, and the routing on top. The faults and diagnostic commands come from real lab builds.
MPLS gives you a private SLA-backed core; DMVPN gives you cheap encrypted connectivity over any internet link. This article compares the two honestly and shows the standard hybrid designs most enterprise WANs end up running.
IKEv1 and IKEv2 configured on the same DMVPN in a CML lab, with real SA output shown side by side. The migration turns out to be a single-line profile swap, and you see exactly why IKEv2 negotiates faster.
A dual-hub DMVPN can black-hole spoke-to-spoke traffic for two hours after a hub fails because of one default timer. This post builds the design in CML, fails a hub, and shows exactly what breaks and how to fix it.
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.
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.
We broke a healthy Phase 3 DMVPN lab three ways on purpose: a spoke that cannot register, an up/up tunnel eating packets, and shortcuts that never form. Real IOS XE 17.18 output shows each failure, including when the hub logs nothing.
DMVPN sends everything cleartext until you add tunnel protection. This post builds the IKEv2 and IPsec profile stack on two Catalyst 8000v routers running IOS XE 17.18, with every show command captured live.
A DMVPN hub relaying routes between spokes trips over split horizon, next-hop handling, and OSPF network types. Run EIGRP named mode and OSPF point-to-multipoint over the same live Phase 3 lab and compare what lands in the RIB.
A complete DMVPN Phase 3 build: one hub, two spokes, a simulated internet underlay, and EIGRP over the top. Every command and every verification step captured from live IOS XE 17.18 devices.
One DMVPN lab reconfigured live from Phase 1 to Phase 2 to Phase 3 on IOS XE 17.18, with the routing table, NHRP cache, and traceroutes captured at each stop. What actually changes in configuration, routing requirements, and the RIB.
NHRP registration, resolution, and redirects are everything interesting DMVPN does. Walk all three message flows with real debugs and cache states from an IOS XE 17.18 lab with one hub and two spokes.