VPN

The hands-on GETVPN build on Cisco IOS XE. Key server first, then group members (nine lines, no peer, no ACL), then verification. Every command verified on cat8000v 17.18.02.

Pre-shared keys are a fine way to learn IPsec and a poor way to run it. A PSK is

GETVPN is the one VPN with no tunnels and no peers. Every site shares one group key. Real IOS XE captures prove it, including the packet capture that explains why GETVPN cannot cross the internet.

PKI is one of those topics that everyone nods along to and almost nobody has actually built. You read about

Every Cisco engineer eventually inherits a router with four different VPN styles bolted onto it: a crypto map for the

The design, the config, and exactly how far we got on a real cat8000v. Hub-and-spoke worked. The NHRP shortcut never fired. Here is how you tell the difference.