Static, OSPF, EIGRP, or eBGP: the PE-CE protocol decides what the customer sees and how fast the L3VPN reconverges. This article runs three of them back to back on the same MPLS lab and shows exactly what changes.
Configure MPLS L3VPN step by step: VRF, RD, RT, LDP, and MP-iBGP carrying VPNv4 between PE routers. Every command and every line of output comes from a five-router Cisco IOS XE lab running OSPF as the core IGP.
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.
DMVPN is three well-understood pieces: mGRE, NHRP, and a routing protocol, each covering a gap the others leave. This walkthrough uses real output from an IOS XE 17.18 lab with a hub, two spokes, and an underlay router.
Multicast fails silently, and nearly every ticket collapses into three signatures: a silent receiver, an RPF failure, or a missing RP. Captured on CML with IOS XE 17.18.2: healthy PIM sparse mode state before and after the source goes active, how to read every field of show ip mroute, and each...
Bidirectional PIM collapses per-source state inside a domain; MSDP carries source knowledge between domains and redundant RPs. Includes a live MSDP peering between two lab RPs and a real SA cache capture.
SSM drops the RP, register tunnel, and shared tree entirely: the receiver names the source and the network builds the (S,G) tree directly. Covers the model, configuration, live IOS XE captures, and an IGMPv3 gotcha that cost the lab twenty minutes.