Had an interesting evening building (emulating) a resilient, dynamic routing LAN. That was quite straightforward, using Cisco’s venerable EIGRP protocol. This was simple enough to configure and test, and was strangely satisfying to see packets reaching their intended destination no matter what I did to the route in between (so long as there was always a possible route). Mesh LAN. Nice.
The rest of my time was spent trying to get frame relay encapsulation working properly, so I can emulate the internet cloud in Packet Tracer. This works fine for the directly-connected devices, but at the moment I can’t get once-or-more-removed subnets to understand the routing path. So R1 > Cloud > R2 is fine but R1 > Cloud > R2 > R3 is not fine. Watching the packets in simulation mode is very interesting, because contrary to what you might expect, the packets do actually reach the destination (R3) but then they just disappear. As far as I can tell R3 makes no attempt to respond. Some sort of encapsulation error probably. Either that or a bug in Packet Tracer.
Tomorrow I’ll be simulating stretching out a VPN over the Cloud. And, I suspect, negotiating the release of some additional Cloud IP addresses with my lecturer! The brief calls for 9 geographically disparate sites to talk to each other. I want to do this using VPNs, but we only have two public IP addresses available to us (or at least only two specified in the brief). Negotiating hat on.