This blog post discusses BGP Labeled Unicast (BGP-LU) which is used in multi-regional networks to carry the label information. While the RFC3107 “Carrying Label Information in BGP-4” explains this topic in more details, we’ve tried to summarize it and highlight the...
In earlier articles, we discussed the next hop and local preference attributes. Today we’ll be looking at the AS_PATH attribute as well as the AS4_PATH attribute. What is an AS PATH? The BGP AS path is a well-known mandatory attribute, which means that...
In our last post, we took a look at RPKI. With RPKI, it’s possible to reject prefixes that are originated by the wrong AS, as well as prefixes longer (more specific) than what the holder of the address block in question intended to be injected into BGP. This...
One thing we all learn quickly after getting started with BGP is that if left to its own devices, the protocol will happily propagate everything everywhere. So when buying transit service from ISPs A and B, your BGP router will send ISP A’s BGP updates to ISP B...
Nowadays, the Internet is made-up of more than 45,000 active Autonomous Systems (ASes), each with a different complexity level and specific configurations. To accomplish efficient traffic flow, a packet must traverse reliable paths through several network nodes,...
