Intermediate · Route reflectors on VyOS · section 2 of 6

Plain iBGP: nothing passed on

✓ Lab-tested 18 October 2026 on VyOS 2026.10.16-0024-rolling, FRR 10.2.1

Start with rr1 as an ordinary iBGP router: a peer group for the three clients, with no reflection. Every session comes up, and rr1 receives c1's and c3's prefixes. But it passes on nothing: PfxSnt 0 for every neighbor, and Not advertised to any peer on c1's route. c2 has an empty BGP table. That's the iBGP rule doing exactly its job.

rr1: an ordinary iBGP peer group

set system host-name 'RR1'
set interfaces ethernet eth0 address '198.51.100.1/24'
set interfaces ethernet eth0 description 'CORE'
set protocols bgp system-as '64500'
set protocols bgp parameters router-id '198.51.100.1'
set protocols bgp peer-group CLIENTS remote-as 'internal'
set protocols bgp peer-group CLIENTS address-family ipv4-unicast
set protocols bgp neighbor 198.51.100.11 peer-group 'CLIENTS'
set protocols bgp neighbor 198.51.100.11 description 'c1'
set protocols bgp neighbor 198.51.100.12 peer-group 'CLIENTS'
set protocols bgp neighbor 198.51.100.12 description 'c2'
set protocols bgp neighbor 198.51.100.13 peer-group 'CLIENTS'
set protocols bgp neighbor 198.51.100.13 description 'c3'

Lines 6–7: The clients' shared settings.
Lines 8–13: The three clients.

Received, not passed on (real output)

vyos@RR1:~$ show ip bgp summary

IPv4 Unicast Summary:
BGP router identifier 198.51.100.1, local AS number 64500 VRF default vrf-id 0
BGP table version 2
RIB entries 2, using 320 bytes of memory
Peers 3, using 90 KiB of memory
Peer groups 1, using 72 bytes of memory

Neighbor        V         AS   MsgRcvd   MsgSent   TblVer  InQ OutQ  Up/Down State/PfxRcd   PfxSnt Desc
198.51.100.11   4      64500         4         3        2    0    0 00:00:17            1        0 c1
198.51.100.12   4      64500         3         3        2    0    0 00:00:17            0        0 c2
198.51.100.13   4      64500         4         3        2    0    0 00:00:17            1        0 c3

Total number of neighbors 3
vyos@RR1:~$ show bgp ipv4 203.0.113.0/24
BGP routing table entry for 203.0.113.0/24, version 2
Paths: (1 available, best #1, table default)
  Not advertised to any peer
  Local
    198.51.100.11 from 198.51.100.11 (198.51.100.11)
      Origin IGP, metric 0, localpref 100, valid, internal, best (First path received)
      Last update: Sat Oct 17 13:48:08 2026
c2# show ip bgp
No BGP prefixes displayed, 0 exist

Lines 11–13: Prefixes received from c1 and c3, nothing sent to anyone.
Line 19: The iBGP rule at work.
Line 25: c2 learns nothing.