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Allied Telesis x908 set atomic-aggregate, set extcommunity rtsoo ext-comm-number, set weight

Models: X8100 x908

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Page 32

BGP: Configuring Route Maps

Atomic- This adds the atomic aggregate attribute to the update. aggregate

Use the command:

set atomic-aggregate

Extended This specifies a value to set as the Extended Community attribute in the update message. community

Use the command:

set extcommunity {rtsoo} <ext-comm-number>

The rt parameter configures a route target extended community. This consists of routers that will receive matching routes.

The soo parameter configures a site-of-origin extended community. This consists of routers that will inject matching routes into BGP.

Next hop This specifies the next hop for matching routes.

Use the command:

set ip next-hop <ipadd>

Originator ID This specifies the Originator ID attribute in the update message. The originator ID is the router ID of the IBGP peer that first learned this route, either via an EBGP peer or by some other means such as importing it.

Use the command:

set originator-id <ipadd>

Weight Specifies a weight value for matching routes. The weight value assists in best path selection of BGP routes. It is stored with the route in the BGP routing table, but is not advertised to peers. When there are multiple routes with a common destination, the device uses the route with the highest weight value.

Use the command:

set weight <0-4294967295>

Dampening This is used to turn out BGP dampening and optionally set dampening parameters for the routes that match the route map entry.

Use one of the commands:

set dampening

set dampening <reachtime>

set dampening <reachtime> <reuse> <suppress> <maxsuppress>

Page 32 Use Route Maps and Other Filters to Filter and Alter BGP and OSPF Routes

Image 32

Allied Telesis x908, X8100 set atomic-aggregate, set extcommunity rtsoo ext-comm-number, set ip next-hop ipadd, set weight

Contents

Introduction Technical GuideContents IntroductionWhich products and software version does it apply to? BGP Applying Route Maps to Imported RoutesRelated How To Notes Which products and software version does it apply to?BGP peers BGP updatesBGP Concepts and Terminology Update attributes OriginAS-path Next-hopAccess Control List ACL filters BGP Overview of the Available Filter TypesFilter types Distribute filtersExamples for filtering BGP Update messages Difference and Relationship in BGPHierarchy of the Different Filters BGP Example Example Distribute filters on page  Example AS path filters on page  Example Prefix filters on pageBasic configuration Confirming the neighbor relationship AlliedWare switchAlliedWare Plus switch awplus#show ip routeBGP Configuring Distribute Filters About ACLsFilter out one particular route from a neighbor Using ACLs as filtersExample Distribute filters Filter out a range of prefix lengths awplusconfig# neighbor 45.45.45.46 distribute-list list2 in awplusconfig-router# do show ip routeawplusconfig# router bgp 3. Check that the IP route table now includes all the routesUse a numbered ACL instead of a named ACL awplusconfig-router# do show ip route 4. Check that the IP route table no longer includes 52.0.0.0/8BGP Configuring AS Path Filters AS path listsDiscard or allow routes from a neighbor Using AS path lists as path filtersExample AS path filters 7. Shut down the neighbor, and then bring it up again 4. Shut down the neighbor, and then bring it up againa neighbor Another example An outgoing filter that uses an AS-path listBGP Configuring AS Path Filters Mask length BGP Configuring Prefix FiltersAbout prefix lists Using prefix lists as prefix filters Example Prefix filtersawplusconfig-router# neighbor neighbor prefix-list list-name in awplusconfig-router# neighbor neighbor prefix-list list-name outFilter out a range of different prefix lengths BGP Configuring Prefix Filters awplusconfig-router# do show ip routeBGP Configuring Route Maps Structure of a route mapAn AS path list Configuring a match clauseClauses Case A community listCase One or more prefixes, by using a prefix list One or more prefixes, by using an ACLConfiguring a set clause A next hop addressAn origin A metric the MED attributeset community community-values additive set weight set atomic-aggregateset extcommunity rtsoo ext-comm-number set ip next-hop ipaddThe effect of different combinations of clauses One match clause with an actionNo match clause and one or more set clauses A match clause and one or more set clausesUpdate from Peer Update 1 to PeerUpdate 2 to Peer Router ASFirst, enter BGP router mode for the AS. The prompt should look like Examples Example B Match on a prefix-list that denies an entryawplusconfig#ip prefix-list test1 permit 52.0.0.0/8 awplusconfig-route-map#set metric4. Apply this route map as the in route map on the neighbor Example D Matching on a next-hop prefix-list Example E Prepending AS numbersawplusconfig-route-map#match ip address awplusconfig-route-map#router bgp1. Configure the AW peer to send out a community number The routes coming from that peer has communityadd ip routem=com entry=1 set commmun=8989 set bgp peer=45.45.45.45 outroutemap=com sendcommunity=yesBGP#show ip route set bgp peer=45.45.45.45 outroutemap=mixed sendcommunity=yes 8. Add that ACL as a distribute-list in-filter on the neighbor route-map marker permit Examples ACLs Path filters Prefix filters Route mapsBGP Applying Route Maps to Imported Routes Syntaxneighbor default-originate Other Uses of Route Mapsneighbor unsuppress-map networkBGP Route Map Filtering Example BGP configurationRoute map configuration set local-preference route-map outdef permit OSPF Configuring Route Maps for Filtering and Modifying OSPF Routes MetricInterface Configuring a match clauseA prefix, by using a prefix list A prefix, by using an ACLExternal route type Configuring a set clauseOSPF Applying Route Maps  Set the metric, by using the command set metric