Enterasys Networks XSR CLI BGP Set Commands, set as-path

BGP Set Commands
6-114 Configuring the Border Gateway Protocol
Syntax
match ip next-hop access-list-number
Syntax of the “no” Form
Thenoformofthiscommandremovesthematchnexthopvalue:
no match ip next-hop access-list-number
Mode
Route‐mapconfiguration:XSR(config-route-map)#
Default
NomatchingbasedonIPnexthop.
Example
ThefollowingexamplesetsthematchingIPnexthopto10:
XSR(config)#access-list 10 permit 1.2.3.4
XSR(config)#route-map 1 permit 1
XSR(config-route-map)#match ip next-hop 10
BGP Set Commands
Routemapsarecomprisedofsetsofmatchandsetcommands.Matchcommandsdefinethematch
criteriaforroutemaps.Routesthatmatchalldefinedmatchcriteriaareprocessedviaset
commandsandthosethatdonotmatchallofthedefinedmatchcriteriaintheroutemapare
ignored.
set as-path
ThiscommandincreasesthelengthoftheAS‐pathattributefortheBGProutingupdatemessages
thatmeetthematchconditionsspecifiedwithinaroutemap.
ThelengthoftheASpathattributeinfluencestheBGProuteselectionprocessfordestinationsthat
canbereachedbymeansofmultiplepaths.ASpathlengthistheonlyglobalBGPmetricthatyou
canusetoinfluencebest‐pathselection.ABGPspeakercaninfluencethebestpathselectionbya
peerbyvaryingthelengthoftheASpath.
Ifyoudonotsetlocalpreferenceorweight,ASpathlengthdetermineswhichofmultipleroutes
areselected.Routeswithlongerautonomoussystempathsarepreferred.Topreferapath,youcan
padtheautonomoussystempathbyprependingextraautonomoussystemnumbers.
Syntax
set as-path prepend as-path-string
access-list-number TheACLtomatch,rangingfrom1to199.
prepend Instructsthesystemtoattachtheas‐path‐stringvaluetotheASpathofthe
routethatmatchestheroutemap.