OpenBGPD - Filter Configuration

"Minimal" filter setup. Deny bogus prefixes.

 # filter out prefixes longer than 24 or shorter than 8 bits
 deny from any
 allow from any prefixlen 8 - 24
  
 # do not accept a default route
 deny from any prefix 0.0.0.0/0
  
 # filter bogus networks
 deny from any prefix 10.0.0.0/8 prefixlen >= 8
 deny from any prefix 172.16.0.0/12 prefixlen >= 12
 deny from any prefix 192.168.0.0/16 prefixlen >= 16
 deny from any prefix 169.254.0.0/16 prefixlen >= 16
 deny from any prefix 192.0.2.0/24 prefixlen >= 24
 deny from any prefix 224.0.0.0/4 prefixlen >= 4
 deny from any prefix 240.0.0.0/4 prefixlen >= 4