• Author : Forhad Ahmed


BGP Add-Path TX

Introduction BGP Add-Path TX allows for a BGP speaker to advertise multiple paths (instead of a single best-path) for a prefix towards a peering BGP speaker (RFC7911). EOS implemented the BGP Add-Path receiver (RX) functionality in 4.15.XF and is implementing the advertisement (TX) functionality in 4.18.0F. There can be several options for choosing exactly which paths to advertise for a prefix to an Add-Path capable peer: Advertise the best-path (same as not configuring Add-Path) Advertise the best-path and the backup path Advertise ECMP paths Advertise any arbitrary subset of paths using an “Add-Path route-map” Advertise all paths In the 4.18.0F...
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BGP 4-byte ASN

At the beginning of 2014 the the Number Resource Organization announced that the pool of 2-byte BGP AS numbers had nearly been depleted (2-byte Autonomous System (AS) Number Pool Nearing Depletion). This feature has been introduced into the 4.15 code release and adds 4-byte AS number support (RFC6793) into Arista’s EOS BGP implementation. The feature extends the number of supported AS numbers from 65535 to 4294967295. BGP speakers┬áthat support 4-byte AS numbers are referred to as NEW BGP speakers, these need to be backward compatible with speakers┬áthat only support 2-byte AS numbers, referred to as OLD BGP speakers. NEW BGP...
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