Enterasys Networks XSR CLI set dampening

BGP Set Commands
6-116 Configuring the Border Gateway Protocol
Syntax of the “no” Form
Thenoformofthiscommandremovesthesetcommunityvalue:
no set community
Mode
Route‐mapconfiguration:XSR(config-route-map)#
Example
Thefollowingexampleconfiguresthesetcommunityvalueinthecontextofconfiguringroutemap
1andtheneighborsendcommunityvalue:
XSR(config)#ip access-list 37 permit 10.0.0.0 255.0.0.0
XSR(config)#route-map 1 permit 1
XSR(config-route-map)#match ip address 37
XSR(config-route-map)#set community 500:10
XSR(config-route-map)#exit
XSR(config)#route-map 1 permit 2
XSR(config-route-map)#set community none
XSR(config-route-map)#exit
XSR(config)#router bgp 100
XSR(config-router)#neighbor 192.168.1.1 remote-as 101
XSR(config-router)#neighbor 192.168.1.1 send-community
XSR(config-router)#neighbor 192.168.1.1 route-map 1 out
Routemap1isappliedtotheoutgoingBGPupdatesbetweenthisrouteranditspeeringneighbor
identifiedbyIPaddress192.168.1.1inAS101.Thefirstinstanceofroutemap1matchesthe
destinationsintheBGPupdatesagainstthecriteriaspecifiedinACL37(10.0.0.0/8).Ifthereisnota
match,thesecondinstanceofroutemap1isinvoked,whichmatchesonallremainingroutesand
removesanycommunityattributes.ThismeansthatroutesmatchingACL37criteriawillhavea
communityattributesetto500:10,butalloftheotherroutesadvertisedto192.168.1.1willnot.
TheBGPpeer192.168.1.1willthenhavetheoptiontoapplyadesiredroutingpolicytoallroutes
arrivingfromthisrouterwiththecommunityattributesetto500:10.
set dampening
Thiscommandconfiguresrouteflapdampening,amechanismtocombatnetworkoverhead
whicharisesfromtheproliferationofuncontrolleddisconnecting/reconnectingnetworks.
Withroutedampening,youcanaddresstheseproblemroutesasfollows:
local-AS Establishedcommunitywhichspecifiesthatroutescontainingthisvalue
shouldnotbeadvertisedtoexternalBGPpeers.
no-advertise Establishedcommunitywhichspecifiesthatroutescontainingthisvalue
shouldnotbeadvertisedtoanyotherBGPpeers(internalorexternal).
no-export Establishedcommunitywhichspecifiesthatroutescontainingthisvalue
shouldnotbeadvertisedoutsideaBGPconfederationboundary.
none Removesanyexistingcommunities.