Continuing on from the previous article, BGP Path Attributes, I’ll cover the remaining popular path attributes.
Multi Exit Discriminator
The MED is an optional non-transitive attribute, which is the metric of BGP. Though other protocols rely almost entirely on the metric to calculate routes, the BGP metric is only used when there are two exit points [...]

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BGP Path attributes describe a prefix being advertised. A previous article mentioned AS-Path, which is an ordered list of the autonomous systems to the destination network. There are many more attributes that describe a route, letting downstream people make informed decisions about how to route a packet.
Path attributes are sent in an UPDATE [...]

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