ASN or Community ?

Someone found a way to cause ExaBGP to mis-behave back in September (2012-09-05) .. The bug was “funny” enough to justify a blog entry, so let’s look at the route which caused it. If you are in an hurry, the answer to the mystery was that a route contained an ASN which could not fit in a Python integer. The patch to fix the issue was a one liner to change the base class of an ASN from an integer to a long …


Interact with BGP from commodity servers.

BGP firewall

If you are protecting your network from packet with spoofed source IP, it is likely that you have to update your routers ACL each time the route you learn from your customers are changing. This can be automated, but could this be done without having to generated ? BGP firewall WARNING This post is kept for nostalgic reason. Please do not use this solution for anything in production as it is more than likely that it will cause issues with any serious traffic.