Juniper iBGP

published: 17th of February 2019

Overview

8 steps to configure iBGP.

  • Configure a router-id
  • Configure an autonomous system number
  • Configure transport routing protocol
  • Configure a BGP group and define the peer type
  • Configure a BGP group local address
  • Add neighbors to the peer group
  • Define a routing policy to export routes
  • Assign the routing policy to the BGP group

Configuration

Configure a router-id.

cmd 
set routing-options router-id 10.255.1.1

Configure an autonomous system number.

cmd 
set routing-options autonomous-system 65100

Configure transport routing protocol.

cmd 
set protocols ospf3 area 0.0.0.0 interface lo0.0 passive
set protocols ospf3 area 0.0.0.0 interface ge-0/0/2.0
set protocols ospf3 realm ipv4-unicast area 0.0.0.0 interface lo0.0 passive
set protocols ospf3 realm ipv4-unicast area 0.0.0.0 interface ge-0/0/2.0

Configure a BGP group and define the peer type.

cmd 
set protocols bgp group IBGP-PEERS type internal

set protocols bgp group IBGPV6-PEERS type internal

Configure a BGP group local address.

cmd 
set protocols bgp group IBGP-PEERS local-address 10.255.1.1

set protocols bgp group IBGPV6-PEERS local-address fd00:10:255:1::1

Add neighbors to the peer group.

cmd 
set protocols bgp group IBGP-PEERS neighbor 10.255.1.2

set protocols bgp group IBGPV6-PEERS neighbor fd00:10:255:1::2

Define a routing policy to export routes.

cmd 
set policy-options policy-statement TO-EBGP-PEERS term 1 from protocol direct
set policy-options policy-statement TO-EBGP-PEERS term 1 then accept

set policy-options policy-statement TO-EBGPV6-PEERS term 1 from protocol direct
set policy-options policy-statement TO-EBGPV6-PEERS term 1 then accept

Assign the routing policy to the BGP group.

cmd 
set protocols bgp group EBGP-PEERS export TO-EBGP-PEERS

set protocols bgp group EBGPV6-PEERS export TO-EBGPV6-PEERS

Topology

network/topologies/2-router.svg

P1R1

cmd 
set routing-options router-id 10.255.1.1
set routing-options autonomous-system 65100
set protocols ospf3 area 0.0.0.0 interface lo0.0 passive
set protocols ospf3 area 0.0.0.0 interface ge-0/0/2.0
set protocols ospf3 realm ipv4-unicast area 0.0.0.0 interface lo0.0 passive
set protocols ospf3 realm ipv4-unicast area 0.0.0.0 interface ge-0/0/2.0
set protocols bgp group IBGP-PEERS type internal
set protocols bgp group IBGP-PEERS local-address 10.255.1.1
set protocols bgp group IBGP-PEERS neighbor 10.255.1.2
set protocols bgp group IBGPV6-PEERS type internal
set protocols bgp group IBGPV6-PEERS local-address fd00:10:255:1::1
set protocols bgp group IBGPV6-PEERS neighbor fd00:10:255:1::2
set policy-options policy-statement T0-IBGP-PEERS term 1 from protocol direct
set policy-options policy-statement T0-IBGP-PEERS term 1 then accept
set policy-options policy-statement T0-IBGPV6-PEERS term 1 from protocol direct
set policy-options policy-statement T0-IBGPV6-PEERS term 1 then accept
set protocols bgp group IBGP-PEERS export T0-IBGP-PEERS
set protocols bgp group IBGPV6-PEERS export T0-IBGPV6-PEERS

P1R2

cmd 
set routing-options router-id 10.255.1.2
set routing-options autonomous-system 65100
set protocols ospf3 area 0.0.0.0 interface lo0.0 passive
set protocols ospf3 area 0.0.0.0 interface ge-0/0/1.0
set protocols ospf3 realm ipv4-unicast area 0.0.0.0 interface lo0.0 passive
set protocols ospf3 realm ipv4-unicast area 0.0.0.0 interface ge-0/0/1.0
set protocols bgp group IBGP-PEERS type internal
set protocols bgp group IBGP-PEERS local-address 10.255.1.2
set protocols bgp group IBGP-PEERS neighbor 10.255.1.1
set protocols bgp group IBGPV6-PEERS type internal
set protocols bgp group IBGPV6-PEERS local-address fd00:10:255:1::2
set protocols bgp group IBGPV6-PEERS neighbor fd00:10:255:1::1
set policy-options policy-statement T0-IBGP-PEERS term 1 from protocol direct
set policy-options policy-statement T0-IBGP-PEERS term 1 then accept
set policy-options policy-statement T0-IBGPV6-PEERS term 1 from protocol direct
set policy-options policy-statement T0-IBGPV6-PEERS term 1 then accept
set protocols bgp group IBGP-PEERS export T0-IBGP-PEERS
set protocols bgp group IBGPV6-PEERS export T0-IBGPV6-PEERS

Verification

Show BGP neighbour info.

cmd 
show bgp neighbor

# output

Peer: 10.255.1.2+56570 AS 65100 Local: 10.255.1.1+179 AS 65100
  Group: IBGP-PEERS            Routing-Instance: master
  Forwarding routing-instance: master
  Type: Internal    State: Established    Flags: <Sync>
  Last State: OpenConfirm   Last Event: RecvKeepAlive
  Last Error: None
  Export: [ T0-IBGP-PEERS ]
  Options: <Preference LocalAddress Refresh>
  Local Address: 10.255.1.1 Holdtime: 90 Preference: 170
  Number of flaps: 0
  Peer ID: 10.255.1.2      Local ID: 10.255.1.1        Active Holdtime: 90
  Keepalive Interval: 30         Group index: 0    Peer index: 0    SNMP index: 3
  I/O Session Thread: bgpio-0 State: Enabled
  BFD: disabled, down
  NLRI for restart configured on peer: inet-unicast
  NLRI advertised by peer: inet-unicast
  NLRI for this session: inet-unicast
  Peer supports Refresh capability (2)
  Stale routes from peer are kept for: 300
  Peer does not support Restarter functionality
  Restart flag received from the peer: Notification
  NLRI that restart is negotiated for: inet-unicast
  NLRI of received end-of-rib markers: inet-unicast
  NLRI of all end-of-rib markers sent: inet-unicast
  Peer does not support LLGR Restarter functionality
  Peer supports 4 byte AS extension (peer-as 65100)
  Peer does not support Addpath
  Table inet.0 Bit: 20000
    RIB State: BGP restart is complete
    Send state: in sync
    Active prefixes:              6
    Received prefixes:            9
    Accepted prefixes:            9
    Suppressed due to damping:    0
    Advertised prefixes:          9
  Last traffic (seconds): Received 397507 Sent 6822 Checked 397507
  Input messages:  Total 255	Updates 2	Refreshes 0	Octets 4955
  Output messages: Total 254	Updates 1	Refreshes 0	Octets 4892
  Output Queue[1]: 0            (inet.0, inet-unicast)

Peer: fd00:10:255:1::2+61842 AS 65100 Local: fd00:10:255:1::1+179 AS 65100
  Group: IBGPV6-PEERS          Routing-Instance: master
  Forwarding routing-instance: master
  Type: Internal    State: Established    Flags: <Sync>
  Last State: OpenConfirm   Last Event: RecvKeepAlive
  Last Error: None
  Export: [ T0-IBGPV6-PEERS ]
  Options: <Preference LocalAddress Refresh>
  Local Address: fd00:10:255:1::1 Holdtime: 90 Preference: 170
  Number of flaps: 0
  Peer ID: 10.255.1.2      Local ID: 10.255.1.1        Active Holdtime: 90
  Keepalive Interval: 30         Group index: 1    Peer index: 0    SNMP index: 4
  I/O Session Thread: bgpio-0 State: Enabled
  BFD: disabled, down
  NLRI for restart configured on peer: inet6-unicast
  NLRI advertised by peer: inet6-unicast
  NLRI for this session: inet6-unicast
  Peer supports Refresh capability (2)
  Stale routes from peer are kept for: 300
  Peer does not support Restarter functionality
  Restart flag received from the peer: Notification
  NLRI that restart is negotiated for: inet6-unicast
  NLRI of received end-of-rib markers: inet6-unicast
  NLRI of all end-of-rib markers sent: inet6-unicast
  Peer does not support LLGR Restarter functionality
  Peer supports 4 byte AS extension (peer-as 65100)
  Peer does not support Addpath
  Table inet6.0 Bit: 30000
    RIB State: BGP restart is complete
    Send state: in sync
    Active prefixes:              6
    Received prefixes:            8
    Accepted prefixes:            8
    Suppressed due to damping:    0
    Advertised prefixes:          8
  Last traffic (seconds): Received 397507 Sent 47584 Checked 397507
  Input messages:  Total 1768	Updates 2	Refreshes 0	Octets 33770
  Output messages: Total 1767	Updates 1	Refreshes 0	Octets 33707
  Output Queue[2]: 0            (inet6.0, inet6-unicast)

Show BGP group info.

cmd 
show bgp group

# output

Group Type: Internal    AS: 65100                  Local AS: 65100
  Name: IBGP-PEERS      Index: 0                   Flags: <>
  Export: [ T0-IBGP-PEERS ]
  Holdtime: 0
  Total peers: 1        Established: 1
  10.255.1.2+56570
  inet.0: 6/9/9/0

Group Type: Internal    AS: 65100                  Local AS: 65100
  Name: IBGPV6-PEERS    Index: 1                   Flags: <>
  Export: [ T0-IBGPV6-PEERS ]
  Holdtime: 0
  Total peers: 1        Established: 1
  fd00:10:255:1::2+61842
  inet6.0: 6/8/8/0

Groups: 2  Peers: 2    External: 0    Internal: 2    Down peers: 0   Flaps: 0
Table          Tot Paths  Act Paths Suppressed    History Damp State    Pending
inet.0
                       9          6          0          0          0          0
inet6.0
                       8          6          0          0          0          0

Show BGP summary info.

cmd 
show bgp summary

# output

Groups: 2 Peers: 2 Down peers: 0
Table          Tot Paths  Act Paths Suppressed    History Damp State    Pending
inet.0
                       9          6          0          0          0          0
inet6.0
                       8          6          0          0          0          0
Peer                     AS      InPkt     OutPkt    OutQ   Flaps Last Up/Dwn State|#Active/Received/Accepted/Damped...
10.255.1.2            65100        259        258       0       0     1:55:32 6/9/9/0              0/0/0/0
fd00:10:255:1::2       65100       1772       1771       0       0    13:14:54 Establ
  inet6.0: 6/8/8/0

Show BGP routing table.

cmd 
show route protocol bgp

# output

inet.0: 56 destinations, 59 routes (56 active, 0 holddown, 0 hidden)
+ = Active Route, - = Last Active, * = Both

10.1.12.0/24        [BGP/170] 01:55:52, localpref 100, from 10.255.1.2
                      AS path: I, validation-state: unverified
                    > to 10.1.12.2 via ge-0/0/2.0
10.1.23.0/24       *[BGP/170] 01:55:52, localpref 100, from 10.255.1.2
                      AS path: I, validation-state: unverified
                    > to 10.1.12.2 via ge-0/0/2.0
10.1.24.0/24       *[BGP/170] 01:55:52, localpref 100, from 10.255.1.2
                      AS path: I, validation-state: unverified
                    > to 10.1.12.2 via ge-0/0/2.0
10.1.25.0/24       *[BGP/170] 01:55:52, localpref 100, from 10.255.1.2
                      AS path: I, validation-state: unverified
                    > to 10.1.12.2 via ge-0/0/2.0
10.1.26.0/24       *[BGP/170] 01:55:52, localpref 100, from 10.255.1.2
                      AS path: I, validation-state: unverified
                    > to 10.1.12.2 via ge-0/0/2.0
10.1.27.0/24       *[BGP/170] 01:55:52, localpref 100, from 10.255.1.2
                      AS path: I, validation-state: unverified
                    > to 10.1.12.2 via ge-0/0/2.0
10.1.28.0/24       *[BGP/170] 01:55:52, localpref 100, from 10.255.1.2
                      AS path: I, validation-state: unverified
                    > to 10.1.12.2 via ge-0/0/2.0
10.255.1.2/32       [BGP/170] 01:55:52, localpref 100, from 10.255.1.2
                      AS path: I, validation-state: unverified
                    > to 10.1.12.2 via ge-0/0/2.0
192.168.121.0/24    [BGP/170] 01:55:52, localpref 100, from 10.255.1.2
                      AS path: I, validation-state: unverified
                    > to 10.1.12.2 via ge-0/0/2.0

inet6.0: 94 destinations, 96 routes (94 active, 0 holddown, 0 hidden)
+ = Active Route, - = Last Active, * = Both

fd00:10:1:12::/64   [BGP/170] 13:15:14, localpref 100, from fd00:10:255:1::2
                      AS path: I, validation-state: unverified
                    > to fe80::2ab7:adff:fe8b:8b46 via ge-0/0/2.0
fd00:10:1:23::/64  *[BGP/170] 13:15:14, localpref 100, from fd00:10:255:1::2
                      AS path: I, validation-state: unverified
                    > to fe80::2ab7:adff:fe8b:8b46 via ge-0/0/2.0
fd00:10:1:24::/64  *[BGP/170] 13:15:14, localpref 100, from fd00:10:255:1::2
                      AS path: I, validation-state: unverified
                    > to fe80::2ab7:adff:fe8b:8b46 via ge-0/0/2.0
fd00:10:1:25::/64  *[BGP/170] 13:15:14, localpref 100, from fd00:10:255:1::2
                      AS path: I, validation-state: unverified
                    > to fe80::2ab7:adff:fe8b:8b46 via ge-0/0/2.0
fd00:10:1:26::/64  *[BGP/170] 13:15:14, localpref 100, from fd00:10:255:1::2
                      AS path: I, validation-state: unverified
                    > to fe80::2ab7:adff:fe8b:8b46 via ge-0/0/2.0
fd00:10:1:27::/64  *[BGP/170] 13:15:14, localpref 100, from fd00:10:255:1::2
                      AS path: I, validation-state: unverified
                    > to fe80::2ab7:adff:fe8b:8b46 via ge-0/0/2.0
fd00:10:1:28::/64  *[BGP/170] 13:15:14, localpref 100, from fd00:10:255:1::2
                      AS path: I, validation-state: unverified
                    > to fe80::2ab7:adff:fe8b:8b46 via ge-0/0/2.0
fd00:10:255:1::2/128
                    [BGP/170] 13:15:14, localpref 100, from fd00:10:255:1::2
                      AS path: I, validation-state: unverified
                    > to fe80::2ab7:adff:fe8b:8b46 via ge-0/0/2.0

Show routes advertised to neighbor.

cmd 
show route advertising-protocol bgp 10.255.1.2

# output

inet.0: 56 destinations, 59 routes (56 active, 0 holddown, 0 hidden)
  Prefix		  Nexthop	       MED     Lclpref    AS path
* 10.1.12.0/24            Self                         100        I
* 10.1.13.0/24            Self                         100        I
* 10.1.14.0/24            Self                         100        I
* 10.1.15.0/24            Self                         100        I
* 10.1.16.0/24            Self                         100        I
* 10.1.17.0/24            Self                         100        I
* 10.1.18.0/24            Self                         100        I
* 10.255.1.1/32           Self                         100        I
* 192.168.121.0/24        Self                         100        I


show route advertising-protocol bgp fd00:10:255:1::2

# output

inet6.0: 94 destinations, 96 routes (94 active, 0 holddown, 0 hidden)
  Prefix		  Nexthop	       MED     Lclpref    AS path
* fd00:10:1:12::/64       Self                         100        I
* fd00:10:1:13::/64       Self                         100        I
* fd00:10:1:14::/64       Self                         100        I
* fd00:10:1:15::/64       Self                         100        I
* fd00:10:1:16::/64       Self                         100        I
* fd00:10:1:17::/64       Self                         100        I
* fd00:10:1:18::/64       Self                         100        I
  fd00:10:255:1::1/128
*                         Self                         100        I

Show routes received from neighbor.

cmd 
show route receive-protocol bgp 10.255.1.2

# output

inet.0: 56 destinations, 59 routes (56 active, 0 holddown, 0 hidden)
  Prefix		  Nexthop	       MED     Lclpref    AS path
  10.1.12.0/24            10.255.1.2                   100        I
* 10.1.23.0/24            10.255.1.2                   100        I
* 10.1.24.0/24            10.255.1.2                   100        I
* 10.1.25.0/24            10.255.1.2                   100        I
* 10.1.26.0/24            10.255.1.2                   100        I
* 10.1.27.0/24            10.255.1.2                   100        I
* 10.1.28.0/24            10.255.1.2                   100        I
  10.255.1.2/32           10.255.1.2                   100        I
  192.168.121.0/24        10.255.1.2                   100        I

inet6.0: 94 destinations, 96 routes (94 active, 0 holddown, 0 hidden)


show route receive-protocol bgp fd00:10:255:1::2

# output

inet.0: 56 destinations, 59 routes (56 active, 0 holddown, 0 hidden)

inet6.0: 94 destinations, 96 routes (94 active, 0 holddown, 0 hidden)
  Prefix		  Nexthop	       MED     Lclpref    AS path
  fd00:10:1:12::/64       fd00:10:255:1::2             100        I
* fd00:10:1:23::/64       fd00:10:255:1::2             100        I
* fd00:10:1:24::/64       fd00:10:255:1::2             100        I
* fd00:10:1:25::/64       fd00:10:255:1::2             100        I
* fd00:10:1:26::/64       fd00:10:255:1::2             100        I
* fd00:10:1:27::/64       fd00:10:255:1::2             100        I
* fd00:10:1:28::/64       fd00:10:255:1::2             100        I
  fd00:10:255:1::2/128
                          fd00:10:255:1::2             100        I

https://www.juniper.net/documentation/en_US/junos/topics/concept/bgp-ibgp-understanding.html

https://www.juniper.net/documentation/en_US/junos/topics/example/routing-protocol-bgp-security-internal-peering-session-configuring-cli.html

https://www.juniper.net/documentation/en_US/junos/topics/topic-map/ospfv3-multiple-address-families.html