After the spin round the block with IOS-XE ‘scaled configuration’ features, this is the accompanying IOS-XR version. First thing first we need to create the ‘long-hand’ version that we used on XE but for XR. The config on XR changes so I’ll notate where appropriate.
router bgp 1000 address-family ipv4 unicast <<< ENABLE IPV4 redistribute connected <<< ADD SOME ROUTES TO FILTER! ! neighbor 1.2.3.5 remote-as 65111 password encrypted 1543595F50 session-open-mode passive-only <<< XE: transport connection-mode passive address-family ipv4 unicast route-policy GOOD2GO in <<< INBOUND POLICY maximum-prefix 10 75 route-policy DEFAULT_ONLY out <<< OUTBOUND POLICY default-originate
Lets just confirm we are getting what we are supposed to on the client router (which is IOS-XE).
Router#sh ip bgp sum BGP router identifier 1.2.3.5, local AS number 65111 BGP table version is 8, main routing table version 8 1 network entries using 248 bytes of memory 1 path entries using 136 bytes of memory 1/1 BGP path/bestpath attribute entries using 288 bytes of memory 1 BGP AS-PATH entries using 24 bytes of memory 0 BGP route-map cache entries using 0 bytes of memory 0 BGP filter-list cache entries using 0 bytes of memory BGP using 696 total bytes of memory BGP activity 6/5 prefixes, 6/5 paths, scan interval 60 secs 4 networks peaked at 14:05:08 Oct 27 2019 UTC (03:08:50.500 ago) Neighbor V AS MsgRcvd MsgSent TblVer InQ OutQ Up/Down State/PfxRcd 1.2.3.4 4 1000 203 212 8 0 0 03:11:20 1
Exercise 1 - The Neighbor-Group
The neighbor-group is similar to the peer-group in XE, i.e. there is no separation between session data and routing policy. In our example we can pretty much paste the existing config into the neighbor-group as seen below:
router bgp 1000 address-family ipv4 unicast redistribute connected ! neighbor-group TESTNG remote-as 65111 password encrypted 1543595F50 session-open-mode passive-only address-family ipv4 unicast route-policy GOOD2GO in maximum-prefix 10 75 route-policy DEFAULT_ONLY out default-originate ! ! neighbor 1.2.3.5 use neighbor-group TESTNG description *** TEST PEER ***
Exercise 2 - The Session-Group
The session-group is similar in function to the peer-session function in XE. It is concerned with the connection between peers at a TCP/IP level. First thing to do is to rip out the neighbor-group and then start building the session-group. one that is done we can inherit the template but using the 'use' keyword.
router bgp 1000 address-family ipv4 unicast redistribute connected ! session-group TESTSG remote-as 65111 password encrypted 1543595F50 session-open-mode passive-only ! neighbor 1.2.3.5 use session-group TESTSG address-family ipv4 unicast route-policy GOOD2GO in maximum-prefix 10 75 route-policy DEFAULT_ONLY out default-originate
Exercise 3 - The AF Template
Last job to do is to use the af-template. The AF template is configured in the main BGP section and must be called from inside the neighbor configuration and the from the relevant address family. Similar to the session template, you can add the template and then 'use' it. After that the neighbor specific details can be removed to leave just the templates.
router bgp 1000 address-family ipv4 unicast redistribute connected ! af-group TESTAFG address-family ipv4 unicast route-policy GOOD2GO in maximum-prefix 10 75 route-policy DEFAULT_ONLY out default-originate ! session-group TESTSG remote-as 65111 password encrypted 1543595F50 session-open-mode passive-only ! neighbor 1.2.3.5 use session-group TESTSG description *** TEST PEER *** address-family ipv4 unicast use af-group TESTAFG
And to finalise, here is some verification data from the XR router:
RP/0/0/CPU0:ios#show bgp ipv4 unicast summary Sun Oct 27 17:52:44.716 UTC BGP router identifier 22.22.22.22, local AS number 1000 BGP generic scan interval 60 secs Non-stop routing is enabled BGP table state: Active Table ID: 0xe0000000 RD version: 5 BGP main routing table version 5 BGP NSR Initial initsync version 2 (Reached) BGP NSR/ISSU Sync-Group versions 0/0 BGP scan interval 60 secs BGP is operating in STANDALONE mode. Process RcvTblVer bRIB/RIB LabelVer ImportVer SendTblVer StandbyVer Speaker 5 5 5 5 5 0 Neighbor Spk AS MsgRcvd MsgSent TblVer InQ OutQ Up/Down St/PfxRcd 1.2.3.5 0 65111 28 37 5 0 0 00:14:55 0 RP/0/0/CPU0:ios#show bgp ipv4 unicast neighbors 1.2.3.5 advertised-routes Sun Oct 27 17:52:08.009 UTC Network Next Hop From AS Path 0.0.0.0/0 0.0.0.0 Local i Processed 1 prefixes, 1 paths
