Wednesday, January 30, 2008

Dynamips, dynagen and GNS3

I've recently been playing around with these router emulators, and I can honestly say I've been impressed. I've tried the three above-mentioned applications in various combinations on differing platforms (Windows XP and Ubuntu Linux), and have had some degree of success in simulating a new project I'm currently working on.

In terms of application, dynamips and dynagen on both XP and Ubuntu are pretty solid. I've tested various platforms (7200, 2600, etc.) and various WAN and LAN scenarios and have been happy with the results.

GNS3 I've only played with on XP, and whilst it's extremely useful, I found it a bit buggy and crash prone. But I guess it's early days for that application, so I won't be too harsh - and I've recomended it to colleagues to try out, which is a kind of endorsement.

What did this help me with? Well, we're in the process of moving from a single ISP to dual ISP configuration, each providing 100Mbps circuits, and we are therefore getting 'provider independent' IP address space and our own BGP ASN.

So I plotted out a scenario with two local internet routers, connecting to two separate ISP routers and an Internet mesh behind them. Internal BGP, external BGP, firewalling and dynamic failover of Internet. All tested on a single XP machine. It makes that test rig I built almost redundant...

Links:

Dynamips
Dynagen
GNS3