Maximum-Prefix
Scenario to verify BGP peer-group maximum-prefix inheritance.
When maximum-prefix is configured on a peer-group, the session closes
if the number of prefixes received exceeds the configured limit.
Test iBGP - Peer-group maximum-prefix closes session on limit exceeded
Description
Test that maximum-prefix configured on a peer-group closes the session when
the prefix limit is exceeded. DUT1 initially advertises 2 prefixes (within limit),
then a third is added to exceed the limit, causing the session to enter Idle (PfxCt).
Scenario
Step 1: Set the following configuration in DUT0 :
set interfaces ethernet eth0 address 10.10.0.100/24 set protocols bgp 20 neighbor peer peer-group MYGROUP set protocols bgp 20 neighbor peer remote-address 10.10.0.200 set protocols bgp 20 neighbor peer remote-as 20 set protocols bgp 20 peer-group MYGROUP maximum-prefix 2 set protocols bgp 20 peer-group MYGROUP remote-as 20 set system login user admin authentication encrypted-password '$6$GSjsCj8gHLv$/VcqU6FLi6CT2Oxn0MJQ2C2tqnRDrYKNF8HIYWJp68nvXvPdFccDsT04.WtigUONbKYrgKg8d6rEs8PjljMkH0'
Step 2: Set the following configuration in DUT1 :
set interfaces ethernet eth0 address 10.10.0.200/24 set protocols bgp 20 neighbor peer remote-address 10.10.0.100 set protocols bgp 20 neighbor peer remote-as 20 set protocols bgp 20 redistribute static set protocols static route 192.168.10.0/24 blackhole set protocols static route 192.168.20.0/24 blackhole set system login user admin authentication encrypted-password '$6$GSjsCj8gHLv$/VcqU6FLi6CT2Oxn0MJQ2C2tqnRDrYKNF8HIYWJp68nvXvPdFccDsT04.WtigUONbKYrgKg8d6rEs8PjljMkH0'
Attention
Verify iBGP session establishes with 2 prefixes (within limit).
Step 3: Run command protocols bgp show ip summary at DUT0 and check if output matches the following regular expressions:
10.10.0.200.*EstablishedShow output
IPv4 Unicast Summary: BGP router identifier 10.10.0.100, local AS number 20 VRF default vrf-id 0 BGP table version 2 RIB entries 3, using 384 bytes of memory Peers 1, using 24 KiB of memory Peer groups 1, using 64 bytes of memory Neighbor LocalAddr V AS MsgRcvd MsgSent TblVer InQ OutQ Up/Down State PfxRcd PfxSnt Desc 10.10.0.200 10.10.0.100 4 20 4 4 2 0 0 00:00:01 Established 2 0 FRRouting/10.4.1 Total number of neighbors 1
Attention
Verify DUT0 receives both routes.
Step 4: Run command protocols bgp show ip at DUT0 and check if output matches the following regular expressions:
192.168.10.0/24[\s\S]+192.168.20.0/24Show output
BGP table version is 2, local router ID is 10.10.0.100, vrf id 0 Default local pref 100, local AS 20 local address - Status codes: s suppressed, d damped, h history, u unsorted, * valid, > best, = multipath, i internal, r RIB-failure, S Stale, R Removed Nexthop codes: @NNN nexthop's vrf id, < announce-nh-self Origin codes: i - IGP, e - EGP, ? - incomplete RPKI validation codes: V valid, I invalid, N Not found Network Next Hop Metric LocPrf Weight Path *>i 192.168.10.0/24 10.10.0.200 0 100 0 ? *>i 192.168.20.0/24 10.10.0.200 0 100 0 ? Displayed 2 routes and 2 total paths
Note
Add a third static route on DUT1 to exceed the maximum-prefix limit.
Step 5: Modify the following configuration lines in DUT1 :
set protocols static route 192.168.30.0/24 blackhole
Attention
Verify session enters Idle (PfxCt) after exceeding maximum-prefix.
Step 6: Run command protocols bgp show ip summary at DUT0 and check if output matches the following regular expressions:
10.10.0.200.*Idle \(PfxCt\)Show output
IPv4 Unicast Summary: BGP router identifier 10.10.0.100, local AS number 20 VRF default vrf-id 0 BGP table version 4 RIB entries 0, using 0 bytes of memory Peers 1, using 24 KiB of memory Peer groups 1, using 64 bytes of memory Neighbor LocalAddr V AS MsgRcvd MsgSent TblVer InQ OutQ Up/Down State PfxRcd PfxSnt Desc 10.10.0.200 10.10.0.100 4 20 5 5 0 0 0 00:00:00 Idle (PfxCt) 0 0 FRRouting/10.4.1 Total number of neighbors 1