Cheatsheet: Difference between revisions
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= BGP =
* Route Selection Criteria
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! Attribute !! Which is better !!
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|Next Hop reachable || Route cannot be used if next hop is unreachable || Well-known Mandatory
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|Weight || Bigger; value local to the router; Cisco proprietary; default is 0 for all routes not originated by local router ||
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|Local Preference || Bigger; used within AS and exchanged bw iBGP routers; default is 100 || Well-known discretionary
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|Locally Injected (Originate) ||
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|AS Path Length || Smaller; e.g: AS path 1 2 3 is preferred over AS path 1 2 3 4 5 || Well-known Mandatory
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|Origin || Prefer
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|MED(Metric) || Smaller; used to advertise to neighbors how they should enter your AS; propagated to all routers within the neighbor AS but not passed along any other AS || Optional non-transitive
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|Neighbor Type || Prefer eBGP over iBGP ||
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|IGP Metric to Next Hop || Smaller; Prefer the path within the AS with the lowest IGP metric to the BGP next hop ||
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|Oldest path || Prefer the path that we received first ||
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|Router ID || Prefer the path with the lowest BGP neighbor router ID (Manually conf > Highest Loopback IP address > Highest Interface IP address) ||
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|Neighbor IP address || Prefer the path with the lowest neighbor IP address ||
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