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Example: Configuring External BGP Point-to-Point Peer Sessions

This example shows how to configure BGP point-to-point peer sessions.

Requirements

Before you begin, if the default BGP policy is not adequate for your network, configure routing policies to filter incoming BGP routes and to advertise BGP routes.

Overview

Figure 1 shows a network with BGP peer sessions. In the sample network, Device E in AS 17 has BGP peer sessions to a group of peers called external-peers. Peers A, B, and C reside in AS 22 and have IP addresses 10.10.10.2, 10.10.10.6, and 10.10.10.10. Peer D resides in AS 79, at IP address 10.21.7.2. This example shows the configuration on Device E.

Figure 1: Typical Network with BGP Peer Sessions

Typical Network with BGP Peer Sessions

Configuration

CLI Quick Configuration

To quickly configure this example, copy the following commands, paste them into a text file, remove any line breaks, change any details necessary to match your network configuration, and then copy and paste the commands into the CLI at the [edit] hierarchy level.

set interfaces ge-1/2/0 unit 0 description to-A set interfaces ge-1/2/0 unit 0 family inet address 10.10.10.1/30 set interfaces ge-0/0/1 unit 5 description to-B set interfaces ge-0/0/1 unit 5 family inet address 10.10.10.5/30 set interfaces ge-0/1/0 unit 9 description to-C set interfaces ge-0/1/0 unit 9 family inet address 10.10.10.9/30 set interfaces ge-1/2/1 unit 21 description to-D set interfaces ge-1/2/1 unit 21 family inet address 10.21.7.1/30 set protocols bgp group external-peers type external set protocols bgp group external-peers peer-as 22 set protocols bgp group external-peers neighbor 10.10.10.2 set protocols bgp group external-peers neighbor 10.10.10.6 set protocols bgp group external-peers neighbor 10.10.10.10 set protocols bgp group external-peers neighbor 10.21.7.2 peer-as 79 set routing-options autonomous-system 17

Step-by-Step Procedure

The following example requires you to navigate various levels in the configuration hierarchy. For information about navigating the CLI, see Using the CLI Editor in Configuration Mode in the CLI User Guide.

To configure the BGP peer sessions:

  1. Configure the interfaces to Peers A, B, C, and D.
    [edit interfaces]user@E# set ge-1/2/0 unit 0 description to-A user@E# set ge-1/2/0 unit 0 family inet address 10.10.10.1/30 user@E# set ge-0/0/1 unit 5 description to-B user@E# set ge-0/0/1 unit 5 family inet address 10.10.10.5/30 user@E# set ge-0/1/0 unit 9 description to-C user@E# set ge-0/1/0 unit 9 family inet address 10.10.10.9/30 user@E# set ge-1/2/1 unit 21 description to-D user@E# set ge-1/2/1 unit 21 family inet address 10.21.7.1/30
  2. Set the autonomous system (AS) number.
    [edit routing-options]user@E# set autonomous-system 17
  3. Create the BGP group, and add the external neighbor addresses.
    [edit protocols bgp group external-peers]user@E# set neighbor 10.10.10.2 user@E# set neighbor 10.10.10.6 user@E# set neighbor 10.10.10.10
  4. Specify the autonomous system (AS) number of the external AS.
    [edit protocols bgp group external-peers]user@E# set peer-as 22
  5. Add Peer D, and set the AS number at the individual neighbor level.

    The neighbor configuration overrides the group configuration. So, while peer-as 22 is set for all the other neighbors in the group, peer-as 79 is set for neighbor 10.21.7.2.

    [edit protocols bgp group external-peers]user@E# set neighbor 10.21.7.2 peer-as 79
  6. Set the peer type to external BGP (EBGP).
    [edit protocols bgp group external-peers]user@E# set type external

Results

From configuration mode, confirm your configuration by entering the show interfaces, show protocols, and show routing-options commands. If the output does not display the intended configuration, repeat the instructions in this example to correct the configuration.

[edit]user@E# show interfaces
ge-1/2/0 {unit 0 {description to-A;family inet {address 10.10.10.1/30;}}}
ge-0/0/1 {unit 5 {description to-B;family inet {address 10.10.10.5/30;}}}
ge-0/1/0 {unit 9 {description to-C;family inet {address 10.10.10.9/30;}}}
ge-1/2/1 {unit 21 {description to-D;family inet {address 10.21.7.1/30;}}}
[edit]user@E# show protocols
bgp {group external-peers {type external;peer-as 22;neighbor 10.10.10.2;neighbor 10.10.10.6;neighbor 10.10.10.10;neighbor 10.21.7.2 {peer-as 79;}}}
[edit]user@E# show routing-optionsautonomous-system 17;

If you are done configuring the device, enter commit from configuration mode.

Verification

Confirm that the configuration is working properly.

Verifying BGP Neighbors

Purpose

Verify that BGP is running on configured interfaces and that the BGP session is active for each neighbor address.

Action

From operational mode, run the show bgp neighbor command.

user@E> show bgp neighbor
Peer: 10.10.10.2+179 AS 22     Local: 10.10.10.1+65406 AS 17   
  Type: External    State: Established    Flags: <Sync>
  Last State: OpenConfirm   Last Event: RecvKeepAlive
  Last Error: None
  Options: <Preference PeerAS Refresh>
  Holdtime: 90 Preference: 170
  Number of flaps: 0
  Peer ID: 10.10.10.2       Local ID: 10.10.10.1       Active Holdtime: 90
  Keepalive Interval: 30         Peer index: 0   
  BFD: disabled, down
  Local Interface: ge-1/2/0.0                       
  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)
  Restart time configured on the peer: 120
  Stale routes from peer are kept for: 300
  Restart time requested by this peer: 120
  NLRI that peer supports restart for: inet-unicast
  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 supports 4 byte AS extension (peer-as 22)
  Peer does not support Addpath
  Table inet.0 Bit: 10000
    RIB State: BGP restart is complete
    Send state: in sync
    Active prefixes:              0
    Received prefixes:            0
    Accepted prefixes:            0
    Suppressed due to damping:    0
    Advertised prefixes:          0
  Last traffic (seconds): Received 10   Sent 6    Checked 1   
  Input messages:  Total 8522   Updates 1       Refreshes 0     Octets 161922
  Output messages: Total 8433   Updates 0       Refreshes 0     Octets 160290
  Output Queue[0]: 0

Peer: 10.10.10.6+54781 AS 22   Local: 10.10.10.5+179 AS 17   
  Type: External    State: Established    Flags: <Sync>
  Last State: OpenConfirm   Last Event: RecvKeepAlive
  Last Error: None
  Options: <Preference PeerAS Refresh>
  Holdtime: 90 Preference: 170
  Number of flaps: 0
  Peer ID: 10.10.10.6       Local ID: 10.10.10.1       Active Holdtime: 90
  Keepalive Interval: 30         Peer index: 1   
  BFD: disabled, down                   
  Local Interface: ge-0/0/1.5                       
  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)
  Restart time configured on the peer: 120
  Stale routes from peer are kept for: 300
  Restart time requested by this peer: 120
  NLRI that peer supports restart for: inet-unicast
  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 supports 4 byte AS extension (peer-as 22)
  Peer does not support Addpath
  Table inet.0 Bit: 10000
    RIB State: BGP restart is complete
    Send state: in sync
    Active prefixes:              0
    Received prefixes:            0
    Accepted prefixes:            0
    Suppressed due to damping:    0
    Advertised prefixes:          0
  Last traffic (seconds): Received 12   Sent 6    Checked 33  
  Input messages:  Total 8527   Updates 1       Refreshes 0     Octets 162057
  Output messages: Total 8430   Updates 0       Refreshes 0     Octets 160233
  Output Queue[0]: 0

Peer: 10.10.10.10+55012 AS 22  Local: 10.10.10.9+179 AS 17   
  Type: External    State: Established    Flags: <Sync>
  Last State: OpenConfirm   Last Event: RecvKeepAlive
  Last Error: None
  Options: <Preference PeerAS Refresh>
  Holdtime: 90 Preference: 170
  Number of flaps: 0
  Peer ID: 10.10.10.10      Local ID: 10.10.10.1       Active Holdtime: 90
  Keepalive Interval: 30         Peer index: 2   
  BFD: disabled, down
  Local Interface: fe-0/1/0.9                       
  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)
  Restart time configured on the peer: 120
  Stale routes from peer are kept for: 300
  Restart time requested by this peer: 120
  NLRI that peer supports restart for: inet-unicast
  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 supports 4 byte AS extension (peer-as 22)
  Peer does not support Addpath
  Table inet.0 Bit: 10000
    RIB State: BGP restart is complete
    Send state: in sync
    Active prefixes:              0
    Received prefixes:            0
    Accepted prefixes:            0
    Suppressed due to damping:    0
    Advertised prefixes:          0
  Last traffic (seconds): Received 15   Sent 6    Checked 37  
  Input messages:  Total 8527   Updates 1       Refreshes 0     Octets 162057
  Output messages: Total 8429   Updates 0       Refreshes 0     Octets 160214
  Output Queue[0]: 0

Peer: 10.21.7.2+61867 AS 79    Local: 10.21.7.1+179 AS 17   
  Type: External    State: Established    Flags: <ImportEval Sync>
  Last State: OpenConfirm   Last Event: RecvKeepAlive
  Last Error: None
  Options: <Preference PeerAS Refresh>
  Holdtime: 90 Preference: 170
  Number of flaps: 0
  Peer ID: 10.21.7.2        Local ID: 10.10.10.1       Active Holdtime: 90
  Keepalive Interval: 30         Peer index: 3   
  BFD: disabled, down
  Local Interface: ge-1/2/1.21                      
  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)
  Restart time configured on the peer: 120
  Stale routes from peer are kept for: 300
  Restart time requested by this peer: 120
  NLRI that peer supports restart for: inet-unicast
  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 supports 4 byte AS extension (peer-as 79)
  Peer does not support Addpath
  Table inet.0 Bit: 10000
    RIB State: BGP restart is complete
    Send state: in sync
    Active prefixes:              0     
    Received prefixes:            0
    Accepted prefixes:            0
    Suppressed due to damping:    0
    Advertised prefixes:          0
  Last traffic (seconds): Received 28   Sent 24   Checked 47  
  Input messages:  Total 8521   Updates 1       Refreshes 0     Octets 161943
  Output messages: Total 8427   Updates 0       Refreshes 0     Octets 160176
  Output Queue[0]: 0

Verifying BGP Groups

Purpose

Verify that the BGP groups are configured correctly.

Action

From operational mode, run the show bgp group command.

user@E> show bgp group
Group Type: External                               Local AS: 17
  Name: external-peers  Index: 0                   Flags: <> 
  Holdtime: 0
  Total peers: 4        Established: 4
  10.10.10.2+179
  10.10.10.6+54781
  10.10.10.10+55012
  10.21.7.2+61867
  inet.0: 0/0/0/0

Groups: 1  Peers: 4    External: 4    Internal: 0    Down peers: 0   Flaps: 0
Table          Tot Paths  Act Paths Suppressed    History Damp State    Pending
inet.0                 0          0          0          0          0          0

Verifying BGP Summary Information

Purpose

Verify that the BGP configuration is correct.

Action

From operational mode, run the show bgp summary command.

user@E> show bgp summary
Groups: 1 Peers: 4 Down peers: 0
Table          Tot Paths  Act Paths Suppressed    History Damp State    Pending
inet.0                 0          0          0          0          0          0
Peer                     AS      InPkt     OutPkt    OutQ   Flaps Last Up/Dwn State|#Active/Received/Accepted/Damped...
10.10.10.2               22       8559       8470       0       0 2d 16:12:56 0/0/0/0              0/0/0/0
10.10.10.6               22       8566       8468       0       0 2d 16:12:12 0/0/0/0              0/0/0/0
10.10.10.10              22       8565       8466       0       0 2d 16:11:31 0/0/0/0              0/0/0/0
10.21.7.2                79       8560       8465       0       0 2d 16:10:58 0/0/0/0              0/0/0/0
 

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Published: 2013-02-08

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