Weight

Scenario to verify BGP peer-group weight configuration.

Weight is a locally significant BGP attribute used to influence path selection. It is the first criterion evaluated in the bestpath algorithm — the route with the highest weight is preferred. When weight is configured on a peer-group, all routes received from neighbors that belong to that peer-group inherit the configured weight value.

In this test, DUT0 defines a peer-group MYGROUP with weight 5 and assigns the neighbor to it. DUT1 redistributes a directly connected network. The test verifies that the route received from DUT1 has the weight value inherited from the peer-group configuration.

Test iBGP - Peer-group weight is applied to received routes

Description

Test that weight configured on a peer-group is inherited by its members. DUT0 creates peer-group MYGROUP with weight 5 and assigns the neighbor to it. DUT1 redistributes connected networks. The test verifies that the route received by DUT0 has weight 5 applied through the peer-group inheritance.

Scenario

Note

DUT0 defines peer-group MYGROUP with weight 5 and assigns the neighbor to it.

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 remote-as 20
set protocols bgp 20 peer-group MYGROUP weight 5
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 connected
set system login user admin authentication encrypted-password '$6$GSjsCj8gHLv$/VcqU6FLi6CT2Oxn0MJQ2C2tqnRDrYKNF8HIYWJp68nvXvPdFccDsT04.WtigUONbKYrgKg8d6rEs8PjljMkH0'

Attention

Verify iBGP session establishes between DUT0 and DUT1.

Step 3: Run command protocols bgp show ip summary at DUT0 and check if output matches the following regular expressions:

10.10.0.200.*Established
Show output
IPv4 Unicast Summary:
BGP router identifier 10.10.0.100, local AS number 20 VRF default vrf-id 0
BGP table version 1
RIB entries 1, using 128 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        1    0    0 00:00:01  Established        1        0 FRRouting/10.4.1

Total number of neighbors 1

Attention

Verify the neighbor is a member of peer-group MYGROUP.

Step 4: Run command protocols bgp show ip neighbors neighbor peer at DUT0 and check if output matches the following regular expressions:

Member of peer-group MYGROUP
Show output
BGP neighbor is 10.10.0.200, remote AS 20, local AS 20, internal link
  Local Role: undefined
  Remote Role: undefined
Hostname: osdx
 Member of peer-group MYGROUP for session parameters
  BGP version 4, remote router ID 10.10.0.200, local router ID 10.10.0.100
  BGP state = Established, up for 00:00:01
  Last read 00:00:00, Last write 00:00:00
  Hold time is 90 seconds, keepalive interval is 30 seconds
  Configured hold time is 90 seconds, keepalive interval is 30 seconds
  Configured tcp-mss is 0, synced tcp-mss is 1448
  Configured conditional advertisements interval is 60 seconds
  Neighbor capabilities:
    4 Byte AS: advertised and received
    AddPath:
      IPv4 Unicast: RX advertised and received
    Paths-Limit:
      IPv4 Unicast: advertised (0) and received (0)
    Long-lived Graceful Restart: advertised and received
      Address families by peer:
    Route refresh: advertised and received
    Enhanced Route Refresh: advertised and received
    Address Family IPv4 Unicast: advertised and received
    Hostname Capability: advertised (name: osdx,domain name: n/a) received (name: osdx,domain name: n/a)
    Version Capability: advertised software version (FRRouting/10.4.1) received software version (FRRouting/10.4.1)
    Link-Local Next Hop Capability: not advertised not received
    Graceful Restart Capability: advertised and received
      Remote Restart timer is 120 seconds
      Address families by peer:
        none
  Graceful restart information:
    End-of-RIB send: IPv4 Unicast
    End-of-RIB received: IPv4 Unicast
    Local GR Mode: Helper*
    Remote GR Mode: Helper
    R bit: True
    N bit: True
    Timers:
      Configured Restart Time(sec): 120
      Received Restart Time(sec): 120
      Configured LLGR Stale Path Time(sec): 0
    IPv4 Unicast:
      F bit: False
      End-of-RIB sent: Yes
      End-of-RIB sent after update: Yes
      End-of-RIB received: Yes
      Timers:
        Configured Stale Path Time(sec): 360
        LLGR Stale Path Time(sec): 0
  Message statistics:
    Inq depth is 0
    Outq depth is 0
                         Sent       Rcvd
    Opens:                  2          1
    Notifications:          0          0
    Updates:                1          2
    Keepalives:             1          1
    Route Refresh:          0          0
    Capability:             0          0
    Total:                  4          4

  Prefix statistics:
    Inbound filtered: 0
    AS-PATH loop: 0
    Originator loop: 0
    Cluster loop: 0
    Invalid next-hop: 0
    Withdrawn: 0
    Attributes discarded: 0

  Minimum time between advertisement runs is 0 seconds

 For address family: IPv4 Unicast
  MYGROUP peer-group member
  Update group 1, subgroup 1
  Packet Queue length 0
  Community attribute sent to this neighbor(all)
  1 accepted, 0 sent prefixes

  Connections established 1; dropped 0
  Last reset 00:00:03,  Waiting for peer OPEN (FRRouting/10.4.1)
  Internal BGP neighbor may be up to 255 hops away.
Local host: 10.10.0.100, Local port: 179
Foreign host: 10.10.0.200, Foreign port: 43162
Nexthop: 10.10.0.100
Nexthop global: fe80::dcad:beff:feef:6c00
Nexthop local: fe80::dcad:beff:feef:6c00
BGP connection: shared network
BGP Connect Retry Timer in Seconds: 30
Estimated round trip time: 0 ms
Read thread: on  Write thread: on  FD used: 25

Attention

Verify route 10.10.0.0/24 is received with weight 5 from the peer-group.

Step 5: Run command protocols bgp show ip 10.10.0.0/24 at DUT0 and check if output matches the following regular expressions:

weight 5
Show output
BGP routing table entry for 10.10.0.0/24, version 1
Paths: (1 available, best #1, table default)
  Not advertised to any peer
  Local
    10.10.0.200 from 10.10.0.200 (10.10.0.200)
      Origin incomplete, metric 0, localpref 100, weight 5, valid, internal, best (First path received)
      Last update: Thu Mar  5 15:47:15 2026