BGP Configuration

show bgp peer-group

[Command]

show bgp peer-group

[Purpose]

This command displays configured BGP peer-groups

[View]

System view

[Use Cases]

sonic# show bgp peer-group
BGP peer-group PEER_V4_EBGP
 Peer-group type is external
 Configured address-families: IPv4 Unicast;
 Peer-group members:
  30.11.13.9 Established
  30.11.13.137 Active
BGP peer-group PEER_V4_IBGP
 Peer-group type is external
 Configured address-families: IPv4 Unicast;
BGP peer-group PEER_V4_INT
 Peer-group type is external
 Configured address-families: IPv4 Unicast;
BGP peer-group PEER_V6_EBGP
 Peer-group type is external
 Configured address-families: IPv4 Unicast;
 Peer-group members:
  2022::9300 Active
  2022::9310 Established
BGP peer-group PEER_V6_IBGP
 Peer-group type is external
 Configured address-families: IPv4 Unicast;
BGP peer-group PEER_V6_INT
 Peer-group type is external
 Configured address-families: IPv4 Unicast;

show ip bgp

[Command] show ip bgp {**view **[all| view_name ] | [**vrf ** [all| vrf_name ]]}

[Purpose]

Display the routing table of BGP view or VRF

[Parameter]

Parameter	Description
view	specify view
view_name	the name of view
vrf	specify VRF
vrf_name	the name of VRF

[View]

System view

[Use Cases]

sonic# show ip bgp vrf all
Instance default:
BGP table version is 2375, local router ID is 30.11.0.84, vrf id 0
Default local pref 100, local AS 65100
Status codes: s suppressed, d damped, h history, * 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
  Network     Next Hop      Metric LocPrf Weight Path
*> 0.0.0.0/0    30.11.13.9               0 65101 4200000001 i

show ip bgp neighbors

[Command]

show ip bgp neighbors

[Purpose]

Display the details of BGP neighbors

[View]

System view

[Use Cases]

sonic# show ip bgp neighbors
BGP neighbor is 1.1.1.2, remote AS 65100, local AS 65200, external link
 BGP version 4, remote router ID 2.1.1.2, local router ID 192.168.15.48
 BGP state = Established, up for 02:34:12
 Last read 00:00:09, Last write 00:00:12
 Hold time is 90, keepalive interval is 30 seconds
 Neighbor capabilities:
  4 Byte AS: advertised
  AddPath:
   IPv4 Unicast: RX advertised IPv4 Unicast
  Route refresh: advertised
  Address Family IPv4 Unicast: advertised and received
  Hostname Capability: advertised (name: sonic,domain name: n/a) not received
  Graceful Restart Capability: advertised
 Graceful restart information:
  Local GR Mode: Helper*
  Remote GR Mode: Disable
  R bit: False
  Timers:
   Configured Restart Time(sec): 120
   Received Restart Time(sec): 0
 Message statistics:
  Inq depth is 0
  Outq depth is 0
                     Sent    Rcvd
  Opens:             3         3
  Notifications:     0         4
  Updates:           2         6
  Keepalives:      338        337
  Route Refresh:     0         0
  Capability:        0         0
  Total:           343        350
 Minimum time between advertisement runs is 0 seconds
 For address family: IPv4 Unicast
 Update group 3, subgroup 3
 Packet Queue length 0
 Community attribute sent to this neighbor(all)
 25 accepted prefixes
 Connections established 3; dropped 2
 Last reset 02:34:17, No AFI/SAFI activated for peer
Local host: 1.1.1.1, Local port: 179
Foreign host: 1.1.1.2, Foreign port: 1051
Nexthop: 1.1.1.1
Nexthop global: fe80::211:24ff:fe1a:1b61
Nexthop local: fe80::211:24ff:fe1a:1b61
BGP connection: shared network
BGP Connect Retry Timer in Seconds: 120
Estimated round trip time: 1 ms
Read thread: on Write thread: on FD used: 27

show ip bgp

[Command]

show ip bgp

[Purpose] Display all route information received from BGP neighbors

[View]

System view

[Use Cases]

sonic# show ip bgp
Instance default:
BGP table version is 3, local router ID is 10.1.1.138, vrf id 0
Default local pref 100, local AS 65001
Status codes: s suppressed, d damped, h history, * 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
*> 10.1.1.138/32  0.0.0.0       0            32768 i
*> 10.1.1.139/32  10.1.1.2      0      0     65002 i
*> 10.1.1.216/32  10.1.1.2      0     65002  65003 i

show ip bgp statistics

[Command]

show ip bgp statistics

[Purpose]

Display BGP routing-related statistics

[View]

System view

[Use Cases]

sonic# show ip bgp statistics
BGP IPv4 Unicast RIB statistics (VRF default)
Total Advertisements          :      25
Total Prefixes                :      25
Average prefix length         :    19.20
Unaggregateable prefixes      :      25
Maximum aggregateable prefixes:      0
BGP Aggregate advertisements  :      0
Address space advertised      :    985600
         % announced          :     0.02
        /8 equivalent         :     0.06
        /24 equivalent        :   3850.00
Advertisements with paths     :      25
Longest AS-Path (hops)        :      1
Average AS-Path length (hops) :     1.00
Largest AS-Path (bytes)       :      6
Average AS-Path size (bytes)  :     6.00
Highest public ASN            :      0

show bgp neighbors log-info

[Command]

show bgp neighbors log-info

[Purpose]

Display the BGP neighbor status information.

[View]

System view

[Usage Scenario] Using this command, you can sequentially view the BGP neighbor’s re-establishment time, the last Errordown time, the reason for the Errordown, and the last establishment time. The reasons for Errordown include Admin. Shutdown (BGP session down), BFD down received (BFD session down), Interface down (interface down), Notification sent (Cease/Other Configuration Change [BGP session information changed] | Hold Timer Expired [BGP message timeout]), Notification received (Cease/Unspecific [BGP session termination] | Cease/Peer De-configured [peer BGP neighbor removed]), etc.

[Use Cases]

sonic(config-router)# do show bgp neighbors log-info
--------------------------------------------------
BGP neighbor is 1.1.1.2
Date/Time    : 2024-12-25 02:32:31
Status       : Up
Date/Time    : 2024-12-25 02:32:01
Status       : Down
Down reason  : Notification sent (Cease/Other Configuration Change)
Date/Time    : 2024-12-25 02:30:09
Status       : Up

router bgp

[Command]

router bgp AS [view view_name |vrf vrf_name ]

no router bgp AS [view view_name |vrf vrf_name ]

[Purpose]

Enable a BGP protocol process with the specified AS number

[Parameter]

Parameter	Description
AS	AS number(1~4294967295) or ASN format as dot notation(0..65535).(0..65535)
view_name	specify the view name
vrf_name	specify the VRF name

[View]

System configuration view

[Notes] When VRF_name is not specified, the BGP protocol process belongs to the default VRF. When expressing ASN in dot notation, the decimal ASN 65538 is equivalent to the dot notation 1.2.

[Use Cases]

sonic# configure terminal
sonic(config)# router bgp 65100
sonic(config-router)#

bgp router-id

[Command]

bgp router-id A.B.C.D

no bgp router-id A.B.C.D

[Purpose]

This command specifies the router-ID

[Parameter]

Parameter	Description
A.B.C.D	configured router identifier

[View]

BGP configuration view

[Use Cases]

sonic# configure terminal
sonic(config)# router bgp 65100
sonic(config-router)# bgp router-id 1.1.1.1

bgp cluster-id

[Command] bgp cluster-id A.B.C.D

no bgp cluster-id A.B.C.D

[Purpose]

Configure the cluster ID for the route reflector

[View]

BGP configuration view

[Usage Scenario] When multiple route reflectors exist within a cluster, it is necessary to configure the same cluster ID to identify that these reflectors belong to the same cluster

[Use Cases]

sonic(config)# router bgp 65100
sonic(config-router)# bgp cluster-id 10.1.1.10

bgp bestpath

[Command]

bgp bestpath [as-path {confed | ignore | multipath-relax}]

no bgp bestpath [as-path {confed | ignore | multipath-relax}]

[Purpose]

Specify the bestpath decision method for BGP

[Parameter]

Parameter	Description
confed	Specifies that BGP considers AS path length and content when selecting the best route
ignore	Ignore the attributes when specifying bgp bestpath decision method multipath-relax. This command specifies that BGP decision process should consider paths of equal AS_PATH length candidates for multipath computation. Without the knob, the entire AS_PATH must match for multipath computation
multipath-relax	Ensure that when comparing routes where both are equal on most metrics, including local-pref, AS_PATH length, IGP cost, MED, that the tie is broken based on router-ID

[View]

BGP configuration view

[Use Cases]

sonic# configure terminal
sonic(config)# router bgp 65100
sonic(config-router)# bgp bestpath as-path ignore

bgp bestpath compare-routerid

[Command]

bgp bestpath compare-routerid

no bgp bestpath compare-routerid

[Purpose]

Configure BGP to ignore Router ID when selecting the best route

[View]

BGP configuration view

[Use Cases]

sonic# configure terminal
sonic(config)# router bgp 65100
sonic(config-router)# bgp bestpath as-path compare-routerid

bgp bestpath bandwidth

[Command]

bgp bestpath bandwidth {default-weight-for-missing|ignore|skip-missing}

no bgp bestpath bandwidth {default-weight-for-missing|ignore|skip-missing}

[Purpose]

Configure BGP’s treatment of bandwidth when selecting the best path

[Parameter]

Parameter	Description
default-weight-for-missing	When a route does not carry a bandwidth parameter, the default action is to assign a weight of 1
ignore	Ignore the bandwidth value in the route
skip-missing	Discard routes that do not carry a bandwidth parameter

[View]

BGP configuration view

[Use Cases]

sonic(config)# router bgp 65100
sonic(config-router)# bgp bestpath bandwidth default-weight-for-missing

bgp ebgp-requires-policy

[Command] bgp ebgp-requires-policy

no bgp ebgp-requires-policy

[Purpose]

This command requires incoming and outgoing filters to be applied for EBGP sessions

[View]

BGP configuration view

[Use Cases]

sonic# configure terminal
sonic(config)# router bgp 65100
sonic(config-router)# bgp ebgp-requires-policy

bgp graceful-restart restart-time

[Command]

bgp graceful-restart restart-time delay

no bgp graceful-restart restart-time delay

[Purpose]

Set the maximum waiting time for the remote end to wait for the successful reconstruction of the local BGP neighbor

[Parameter]

Parameter	Description
delay	Range value: 1-4094, unit: s

[View]

BGP configuration view

[Usage Scenario] After executing this command, when the remote device detects that the BGP peer established with the local device is in a Down state, it triggers the BGP session to enter Graceful Restart mode. During this time, the device can continue to use previously learned routing information without waiting for the BGP session to be reestablished. If the maximum waiting time is exceeded without a successful reconnection, the device exits the Graceful Restart process and withdraws routes.

[Use Cases]

sonic# configure terminal
sonic(config)# router bgp 65100
sonic(config-router)# bgp graceful-restart restart-time 200

bgp graceful-restart rib-stale-time

[Command]

bgp graceful-restart rib-stale-time delay

no bgp graceful-restart rib-stale-time delay

[Purpose]

Configure the maximum waiting time for the local end to wait for the End-Of-RIB marker from the remote end

[Parameter]

Parameter	Description
delay	Range value: 1-3600, unit: s

[View]

BGP configuration view

[Usage Scenario] After the local end and remote end rebuild the BGP session, the local end should receive the End-Of-RIB marker from the remote end within the time set by this command. If the End-Of-RIB marker is not received within the specified time, the local end will exit the Graceful Restart process and withdraw routes.

[Use Cases]

sonic# configure terminal
sonic(config)# router bgp 65100
sonic(config-router)# bgp graceful-restart rib-stale-time 20

bgp shutdown

[Command]

**bgp shutdown ** [message String ]

**no bgp shutdown ** [message String ]

[Purpose]

Administrative shutdown of all peers of a BGP instance

[Parameter]

Parameter	Description
string	An optional shutdown message MSG can be specified.

[View]

BGP configuration view

[Use Cases]

sonic# configure terminal
sonic(config)# router bgp 65100
sonic(config-router)# bgp shutdown message testing

bgp network import-check

[Command]

bgp network import-check

no bgp network import-check

[Purpose]

Check for the networks existence in RIB

[View]

BGP configuration view

[Usage Scenario] This configuration modifies the behavior of the network statement. If you have this configured the underlying network must exist in the rib. If you have the [no] form configured then BGP will not check for the networks existence in the rib. For versions 7.3 and before frr defaults for datacenter were the network must exist, traditional did not check for existence. For versions 7.4 and beyond both traditional and datacenter the network must exist.

[Use Cases]

sonic# configure terminal
sonic(config)# router bgp 65100
sonic(config-router)# bgp network import-check

bgp update-delay

[Command]

bgp update-delay MAX-DELAY [ ESTABLISH-WAIT ] no bgp update-delay MAX-DELAY [ ESTABLISH-WAIT ]

[Purpose]

Configuring a global delay for sending Update messages

[Parameter]

Parameter	Description
MAX-DELAY	Max delay in seconds (0..3600)
ESTABLISH-WAIT	Establish wait in seconds (1..3600)

[View]

System configuration view

[Use Cases]

sonic# configure terminal
sonic(config)# bgp update-delay 2 2

update-delay

[Command] update-delay MAX-DELAY

no update-delay MAX-DELAY

[Purpose]

This command is used to delay the advertisement of BGP routes after a BGP process is restarted.

[Parameter]

Parameter	Description
MAX-DELAY	Range value: 0-3600, unit: s

[View]

BGP configuration view

[Use Cases]

sonic# configure terminal
sonic(config)# router bgp 65100
sonic(config-router)# update-delay 2

distance

[Command]

distance ebpg_distance ibgp_distance local_distance

distance distance A.B.C.D/M [ip-prefix-name]

no distance ebpg_distance ibgp_distance local_distance

no distance distance A.B.C.D/M [ip-prefix-name]

[Purpose]

Modify the administrative distance for the route

[Parameter]

Parameter	Description
ebpg_distance	Modify the administrative distance of EBGP routes, the value range: 1-255
ibgp_distance	Modify the administrative distance of IBGP routes, the value range is 1-255
local_distance	Change the administrative distance of the local route, the value range is 1-255
distance	Sets the administrative distance for a particular route
A.B.C.D/M	IP-prefix
ip-prefix-name	The name of ip-prefix list

[View]

BGP configuration view

[Usage Scenario] If the system has a static route configured from the kernel, it has a distance of 0. In some cases, it might be useful to override the route. E.g.: Kernel has a statically configured default route, and you received another default route from the BGP and want to install it to be preferred over the static route. In such a case, user can set a higher distance from the kernel. By default, the administrative distance for EBGP routes is 200, the administrative distance for IBGP routes is 20, and the administrative distance for local routes is 1.

[Use Cases]

sonic# configure terminal
sonic(config)# router bgp 65100
sonic(config-router)# distance 20 0.0.0.0/0

redistribute

[Command]

**redistribute ** [babel|connected|eigrp|isis|kernel|openfabric|ospf|ospf6|rip|ripng|sharp|static|table|vnc|vnc-direct] [metric metric_id ] [route-map String ] **no redistribute ** [babel|connected|eigrp|isis|kernel|openfabric|ospf|ospf6|rip|ripng|sharp|static|table|vnc|vnc-direct] [metric metric_id ] [route-map String ]

[Purpose]

Redistribute routes from other protocols into BGP

[Parameter]

Parameter	Description
metric_id	Set the metric for route
route-map String	Apply a route-map

[View]

Address-family view

[Use Cases]

sonic# configure terminal
sonic(config)# router bgp 65100
sonic(config-router)# address-family ipv4 unicast
sonic(config-router-af)# redistribute ospf metric 200

bgp listen range

[Command]

bgp listen range { A.B.C.D/M | X:X::X:X*/M* } peer-group name

no bgp listen range { A.B.C.D/M | X:X::X:X*/M* } peer-group name

[Purpose]

Allow establishing BGP neighbor relationships with all IP addresses within the specified address range

[Parameter]

Parameter	Description
A.B.C.D/M X:X::X:X*/M*	IP range
name	Peer group name

[View]

BGP configuration view

[Use Cases]

sonic(config)# router bgp 65100
sonic(config-router)# neighbor TEST peer-group
sonic(config-router)# neighbor TEST remote-as external
sonic(config-router)# bgp listen range 10.111.1.0/24 peer-group TEST

bgp listen limit

[Command]

bgp listen limit neighor_number

no bgp listen limit neighor_number

[Purpose] Define the maximum number of peers accepted for one BGP instance

[Parameter]

Parameter	Description
neighbor_number	Configure Dynamic Neighbors listen limit value (1..5000)

[View]

BGP configuration view

[Use Cases]

sonic# configure terminal
sonic(config)# router bgp 65100
sonic(config-router)# bgp listen limit 20

bgp default ipv4-unicast

[Command]

bgp default ipv4-unicast

no bgp default ipv4-unicast

[Purpose]

IPv4 unicast address families for all neighbors are enabled by default

[View]

BGP configuration view

[Notes] By default, all neighbors do not enable the IPv4 unicast address family and require manual configuration to set their state to Active. After configuring the bgp default ipv4-unicast command, the created BGP peer automatically enables the IPv4 unicast address family by default.

[Use Cases]

sonic# configure terminal
sonic(config)# router bgp 65100
sonic(config-router)# bgp default ipv4-unicast

bgp default local-preference

[Command]

bgp default local-preference value

no bgp default local-preference value

[Purpose]

configuring the default local preference for BGP

[View]

BGP configuration view

[Notes] By default, the default local priority is 100.

[Use Cases]

sonic# configure terminal
sonic(config)# router bgp 65100
sonic(config-router)# bgp default local-preference 100

bgp default shutdown

[Command]

bgp default shutdown

no bgp default shutdown

[Purpose]

Set the default state of the newly configured peer to shutdown

[View]

BGP configuration view

[Notes] After configuring this command, all newly added BGP peers will require manual configuration of the no shutdown command to be used properly.

[Use Cases]

sonic# configure terminal
sonic(config)# router bgp 65100
sonic(config-router)# bgp default shutdown

bgp route-reflector allow-outbound-policy

[Command] bgp route-reflector allow-outbound-policy

no bgp route-reflector allow-outbound-policy

[Purpose]

Allowing route policies to affect reflected routes

[View]

BGP configuration view

[Usage Scenario] By default, policies that modify route attributes configured in a route-map do not affect routes that are reflected by route reflectors. Enabling this feature allows route attributes to be modified and take effect on all reflected routes.

[Use Cases]

sonic# configure terminal
sonic(config)# router bgp 65100
sonic(config-router)# bgp route-reflector allow-outbound-policy

bgp fast-external-failover

[Command]

bgp route-reflector allow-outbound-policy

no bgp route-reflector allow-outbound-policy

[Purpose]

Enable BGP to immediately close the EBGP peer when there is link instability.

[View]

BGP configuration view

[Use Cases]

sonic# configure terminal
sonic(config)# router bgp 65100
sonic(config-router)# bgp fast-external-failover

aggregate-address

[Command]

aggregate-address ip-address { mask-length | mask } [as-set|summary-only|route-map String |origin{incomplete|igp|egp}]

no aggregate-address ip-address { mask-length | mask } [as-set|summary-only|route-map String |origin{incomplete|igp|egp}]

[Purpose]

This command specifies an aggregate address

[Parameter]

Parameter	Description
ip-address	Specifies an IP address of the summarized route. Theaddress is in dotted decimal notation
mask	IP address mask, the address is in dotted decimal natation
mask-length	Length of the IP address mask
as-set	Include AS-set in the generated routes
summary-only	Announce only the aggregated route
route-map String	Apply a route-map for an aggregated prefix
origin{incomplete|igp|egp}	Specify ORIGIN for an aggregated prefix

[View]

IP Address-family View

[Usage Scenario] This command can be used to aggregate and advertise routes from the local routing table. To ensure that the aggregated routes have loop prevention, you can use the “as-set” keyword to create an aggregate route that inherits the Origin, AS_Path, Community, and large-community attributes from the specific routes. By configuring “summary-only,” you can suppress all the detailed routes included in the aggregate route, only announcing the aggregate route. This helps reduce the routing load on BGP peers.

[Use Cases]

sonic# configure terminal
sonic(config)# router bgp 65100
sonic(config-router)# address-family ipv6 unicast
sonic(config-router-af)# aggregate-address 100::1/64

network

[Command]

network ip-address { mask-length | mask } [ route-map string ]

no network *ip-address { mask-length | mask } [ route-map string ]

[Purpose] This command adds the announcement network.

[Parameter]

Parameter	Description
A.B.C.D	IP address, the address is in dotted decimal natation
mask	IP address mask, the address is in dotted decimal natation
mask-length	Length of the IP address mask
route-map string	Apply a route-map for an aggregated prefix

[View]

IP address-family view

[Use Cases]

sonic# configure terminal
sonic(config)# router bgp 65100
sonic(config-router)# address-family ipv4 unicast
sonic(config-router-af)# network 1.1.1.0/24

neighbor graceful-restart

[Command]

neighbor { A.B.C.D | X:X::X:X | String } {graceful-restart|graceful-restart-disable|graceful-restart-helper}

no neighbor { A.B.C.D | X:X::X:X | String } {graceful-restart|graceful-restart-disable|graceful-restart-helper}

[Purpose]

This command will enable BGP graceful restart functionality.

[Parameter]

Parameter	Description
A.B.C.D	Neighbor address
X:X::X:X	Neighbor IPv6 address
String	Peer-group name
gracefule-restart	Graceful Restart command for a neighbor
gracefule-restart-disable	Graceful Restart Disable command for a neighbor
gracefule-restart-helper	Graceful Restart Helper command for a neighbor

[View]

BGP configuration view

[Use Cases]

sonic# configure terminal
sonic(config)# router bgp 65100
sonic(config-router)# neighbor 1.1.1.1 graceful-restart

neighbor advertisement-interval

[Command]

neighbor { A.B.C.D | X:X::X:X | String } advertisement-interval internal

no neighbor { A.B.C.D | X:X::X:X | String } advertisement-interval internal

[Purpose]

Configure the time interval for a peer to send route prefix update messages

[Parameter]

Parameter	Description
A.B.C.D	Neighbor address
X:X::X:X	Neighbor IPv6 address
String	Peer-group name
internal	The range of value: 0-600, default value is: 0

[View]

BGP configuration view

[Use Cases]

sonic# configure terminal
sonic(config)# router bgp 65100
sonic(config-router)# neighbor 1.1.1.1 advertisement-interval 2

neighbor bfd

[Command]

neighbor { A.B.C.D | X:X::X:X | String } bfd [date-plane]

[Purpose] Enable BFD functionality for a specific peer

[Parameter]

Parameter	Description
date-plane	Specify that locally generated BFD packets are processed by the hardware

[View]

BGP configuration view

[Usage Scenario] By default, when BFD functionality is enabled, both the reception and transmission of BFD packets on the device are processed by the CPU. If the device is running multiple network protocols and the CPU is relatively busy, it may lead to inaccurate BFD detection results due to CPU processing delays. Enabling this feature ensures that BFD packets generated locally by the device are processed by the hardware, reducing the performance load on the CPU

[Use Cases]

sonic(config) router bgp 65100
sonic(config-router)# neighbor 44.1.3.1 remote-as external
sonic(config-router)# neighbor 44.1.3.1 bfd data-plane

neighbor capability extended-nexthop

[Command]

neighbor { A.B.C.D | X:X::X:X | String } capability extended-nexthop

no neighbor { A.B.C.D | X:X::X:X | String } capability extended-nexthop

[Purpose]

Allow BGP to negotiate extended next-hop capability with its peers

[Parameter]

Parameter	Description
A.B.C.D	Neighbor address
X:X::X:X	Neighbor IPv6 address
String	Peer-group name

[View]

BGP configuration view

[Notes] Allow bgp to negotiate the extended-nexthop capability with it’s peer. If user is peering over a IPv6 LL address then this capability is turned on automatically. If user is peering over a IPv6 Global Address then turning on this command will allow BGP to install IPv4 routes with IPv6 nexthops if you do not have IPv4 configured on interfaces.

[Use Cases]

sonic# configure terminal
sonic(config)# router bgp 65100
sonic(config-router)# neighbor 1.1.1.1 capability extended-nexthop

neighbor capability dynamic

[Command]

neighbor { A.B.C.D | X:X::X:X | String } capability dynamic

no neighbor { A.B.C.D | X:X::X:X | String } capability dynamic

[Purpose]

Allow bgp to negotiate the extended-nexthop capability with it’s peer.

[Parameter]

Parameter	Description
A.B.C.D	Neighbor address
X:X::X:X	Neighbor IPv6 address
String	Peer-group name

[View]

BGP configuration view

[Notes] Dynamic Capability defines a new BGP message (CAPABILITY) that can be used to set/unset BGP capabilities without bringing down a BGP session. This includes changing graceful-restart (LLGR also) timers, enabling/disabling add-path, and other supported capabilities.

[Use Cases]

sonic# configure terminal
sonic(config)# router bgp 65100
sonic(config-router)# neighbor 1.1.1.1 capability dynamic

neighbor description

[Command]

neighbor { A.B.C.D | X:X::X:X | String } description String

no neighbor { A.B.C.D | X:X::X:X | String } description String

[Purpose]

Set description of the peer.

[Parameter]

Parameter	Description
A.B.C.D	Neighbor address
X:X::X:X	Neighbor IPv6 address
String	Peer-group name
String	Describing this neighbor

[View]

BGP configuration view

[Use Cases]

sonic# configure terminal
sonic(config)# router bgp 65100
sonic(config-router)# neighbor 1.1.1.1 description test

neighbor disable-connected-check

[Command]

neighbor { A.B.C.D | X:X::X:X | String } disable-connected-check

no neighbor { A.B.C.D | X:X::X:X | String } disable-connected-check

[Purpose]

Allow peerings between directly connected EBGP peers using loopback addresses.

[Parameter]

Parameter	Description
A.B.C.D	Neighbor address
X:X::X:X	Neighbor IPv6 address
String	Peer-group name

[View]

BGP configuration view

[Use Cases]

sonic# configure terminal
sonic(config)# router bgp 65100
sonic(config-router)# neighbor 1.1.1.1 disable-connected-check

neighbor ebgp-multihop

[Command]

neighbor { A.B.C.D | X:X::X:X | String } ebgp-multihop count

no neighbor { A.B.C.D | X:X::X:X | String } ebgp- multihop count

[Purpose]

Specifying ebgp-multihop allows sessions with eBGP neighbors to establish when they are multiple hops away

[Parameter]

Parameter	Description
A.B.C.D	Neighbor address
X:X::X:X	Neighbor IPv6 address
String	Peer-group name
count	Maximum hop count (1..255)

[View]

BGP configuration view

[Use Cases]

sonic# configure terminal
sonic(config)# router bgp 65100
sonic(config-router)# neighbor 1.1.1.1 ebgp-multihop 2

neighbor interface

[Command]

neighbor { A.B.C.D | X:X::X:X | String } interface interface_name

no neighbor { A.B.C.D | X:X::X:X | String } interface interface_name

[Purpose]

When you connect to a BGP peer over an IPv6 link-local address, you have to specify the IFNAME of the interface used for the connection.

[Parameter]

Parameter	Description
A.B.C.D	Neighbor address
X:X::X:X	Neighbor IPv6 address
String	Interface name or neighbor tag
interface_name	Interface name

[View]

BGP configuration view

[Usage Scenario] When you connect to a BGP peer over an IPv6 link-local address, you have to specify the IFNAME of the interface used for the connection. To specify IPv4 session addresses, see the neighbor PEER update-source command below

[Use Cases]

sonic# configure terminal
sonic(config)# router bgp 65100
sonic(config-router)# neighbor 1.1.1.1 interface Ethernet49

neighbor local-as

[Command]

neighbor { A.B.C.D | X:X::X:X | String } local-as ASN [no-prepend] [replace-as]

no neighbor { A.B.C.D | X:X::X:X | String } local-as ASN [no-prepend] [replace-as]

[Purpose] Specify an alternate AS for this BGP process when interacting with the specified peer

[Parameter]

Parameter	Description
A.B.C.D	Neighbor address
X:X::X:X	Neighbor IPv6 address
String	Interface name or neighbor tag
ASN	AS number

[View]

BGP configuration view

[Usage Scenario] Specify an alternate AS for this BGP process when interacting with the specified peer. With no modifiers, the specified local-as is prepended to the received AS_PATH when receiving routing updates from the peer, and prepended to the outgoing AS_PATH (after the process local AS) when transmitting local routes to the peer. If the no-prepend attribute is specified, then the supplied local-as is not prepended to the received AS_PATH. If the replace-as attribute is specified, then only the supplied local-as is prepended to the AS_PATH when transmitting local-route updates to this peer.

[Notes] Note that replace-as can only be specified if no-prepend is.

[Use Cases]

sonic# configure terminal
sonic(config)# router bgp 65100
sonic(config-router)# neighbor 1.1.1.1 local-as 123 no-prepend replace-as

neighbor password

[Command] neighbor { A.B.C.D | X:X::X:X | String } password PASSWORD

neighbor { A.B.C.D | X:X::X:X | String } password PASSOWRD

[Purpose]

Set a MD5 password to be used with the tcp socket that is being used to connect to the remote peer

[Parameter]

Parameter	Description
A.B.C.D	Neighbor address
X:X::X:X	Neighbor IPv6 address
String	IPeer-group name
PASSWORD	The password

[View]

BGP configuration view

[Usage Scenario] To enhance the security of BGP connections, MD5 authentication can be used during the establishment of TCP connections. When the passwords at both ends of the BGP neighbors do not match, the BGP neighbor establishment will fail.

[Notes] It is important to note that the key will be displayed in ciphertext, meaning that the password will not be visible in plain text.

[Use Cases]

sonic# configure terminal
sonic(config)# router bgp 65100
sonic(config-router)# neighbor 1.1.1.1 password test1234

neighbor port

[Command]

neighbor { A.B.C.D | X:X::X:X | String } port PORT

no neighbor { A.B.C.D | X:X::X:X | String } port PORT

[Purpose]

Specify the L4-port to use for the BGP session to this neighbor

[Parameter]

Parameter	Description
A.B.C.D	Neighbor address
X:X::X:X	Neighbor IPv6 address
String	Peer-group name
PORT	TCP port number (0..65535)

[View]

BGP configuration view

[Use Cases]

sonic# configure terminal
sonic(config)# router bgp 65100
sonic(config-router)# neighbor 1.1.1.1 port 234

neighbor remote-as

[Command]

neighbor { A.B.C.D | X:X::X:X | String } remote-as [ ASN |internal|external]

no neighbor { A.B.C.D | X:X::X:X | String } remote-as [ ASN |internal|external]

[Purpose]

Create a new neighbor whose remote-as is ASN

[Parameter]

Parameter	Description
A.B.C.D	Neighbor address
X:X::X:X	Neighbor IPv6 address
String	Peer-group name
ASN	AS number

[View]

BGP configuration view

[Use Cases]

sonic# configure terminal
sonic(config)# router bgp 65100
sonic(config-router)# neighbor 1.1.1.1 remote-as 65101
sonic(config-router)# neighbor 1.1.1.1 remote-as external

neighbor peer-group

[Command]

neighbor peer-group-name peer-group

no neighbor peer-group-name peer-group

[Purpose]

Create a peer group

[View]

BGP configuration view

[Usage Scenario] In large-scale BGP networks, the number of peers can be substantial, and many of these peers share similar policies. Configuring these peers can be repetitive, but using peer groups can simplify the configuration process. When a user wants to apply the same configuration to several peers, they can create a peer group, configure it accordingly, and then add the peers to that group. This way, all peers within the group inherit the group’s configuration.

[Use Cases]

sonic# configure terminal
sonic(config)# router bgp 65100
sonic(config-router)# neighbor PEER_V4_EBGP peer-group

neighbor peer-group

[Command] neighbor { A.B.C.D | X:X::X:X | String } peer-group NAME

no neighbor { A.B.C.D | X:X::X:X | String } peer-group NAME

[Purpose]

This command bind specific peer to peer group

[Parameter]

Parameter	Description
A.B.C.D	Neighbor address
X:X::X:X	Neighbor IPv6 address
NAME	peer-group name

[View]

BGP configuration view

[Usage Scenario] A peer group is a collection of peers with similar policies or attributes. When a peer joins a peer group, the configuration settings for that peer group apply to all members within the group. In situations where there are a significant number of peers with identical configurations in the network, configuring peer groups can streamline the setup process.

[Use Cases]

sonic# configure terminal
sonic(config)# router bgp 65100
sonic(config-router)# neighbor 1.1.1.1 peer-group PEER_V4_EBGP

neighbor update-source

[Command]

neighbor { A.B.C.D | X:X::X:X | String } update-source { A.B.C.D | X:X::X:X | String }

no neighbor { A.B.C.D | X:X::X:X | String } update-source { A.B.C.D | X:X::X:X | String }

[Purpose]

Specify the IPv4 source address to use for the BGP session to this neighbor

[Parameter]

Parameter	Description
A.B.C.D	Neighbor address
X:X::X:X	Neighbor IPv6 address
String	Peer-group name

[View]

BGP configuration view

[Usage Scenario] Specify the IPv4 source address to use for the BGP session to this neighbor, may be specified as either an IPv4 address directly or as an interface name.

[Use Cases]

sonic# configure terminal
sonic(config)# router bgp 65100
sonic(config-router)# neighbor 1.1.1.1 update-source Ethernet49

neighbor activate

[Command]

neighbor { A.B.C.D | X:X::X:X | String } activate

no neighbor { A.B.C.D | X:X::X:X | String } activate

[Purpose]

Enable a specific BGP peer

[Parameter]

Parameter	Description
A.B.C.D	IPv4 address
X:X::X:X	IPv6 address

[View]

IP Address-family view

[Notes] By default, only the IPv4 unicast address family is announced to all neighbors. Using the no bgp default ipv4-unicast configuration overrides this default so that all address families need to be enabled explicitly

[Use Cases]

sonic# configure terminal
sonic(config)# router bgp 65100
sonic(config-router)# address-family ipv4 unicast
sonic(config-router-af)# network 1.1.1.1 activate

neighbor allowas-in

[Command]

neighbor { A.B.C.D | X:X::X:X | String } **allowas-in ** [ number |origin]

no neighbor { A.B.C.D | X:X::X:X | String } **allowas-in ** [ number |origin]

[Purpose] This command accepts incoming routes with AS paths that have the same value as the current system’s AS

[Parameter]

Parameter	Description
A.B.C.D	Neighbor address
X:X::X:X	Neighbor IPv6 address
String	Interface name or neighbor tag
number	Number of occurrences of AS number (1..10)

[View]

IP address-family view

[Usage Scenario] Normally, BGP determines the presence of loops by checking for the presence of the same AS number in the AS_PATH attribute. This command allows you to configure the maximum number of times the local AS number is allowed to repeat, meeting the requirements of special scenarios。

[Use Cases]

sonic# configure terminal
sonic(config)# router bgp 65100
sonic(config-router)# address-family ipv4 unicast
sonic(config-router-af)# neighbor 1.1.1.1 allowas-in 2

neighbor as-override

[Command]

neighbor { A.B.C.D | X:X::X:X | String } as-override

no neighbor { A.B.C.D | X:X::X:X | String } as-override

[Purpose]

Override AS number of the originating router with the local AS number

[Parameter]

Parameter	Description
A.B.C.D	Neighbor address
X:X::X:X	Neighbor IPv6 address
String	Interface name or neighbor tag

[View]

IP address-family view

[Use Cases]

sonic# configure terminal
sonic(config)# router bgp 65100
sonic(config-router)# address-family ipv4 unicast
sonic(config-router-af)# neighbor 1.1.1.1 as-override

neighbor attribute-unchanged

[Command]

neighbor { A.B.C.D | X:X::X:X | String }**attribute-unchanged ** [{as-path|next-hop|med}]**no neighbor { A.B.C.D | X:X::X:X | String } **attribute-unchanged ** [{as-path|next-hop|med}]

[Purpose]

Preserve the next hop when advertising routes to a specified EBGP peer

[Parameter]

Parameter	Description
A.B.C.D	Neighbor address
X:X::X:X	Neighbor IPv6 address
String	Peer group name

[View]

IP address-family view

[Use Cases]

sonic# configure terminal
sonic(config)# router bgp 65100
sonic(config-router)# address-family ipv4 unicast
sonic(config-router-af)# neighbor 1.1.1.1 attribute-unchanged as-path

neighbor default-originate

[Command]

neighbor { A.B.C.D | X:X::X:X | String } **default-originate ** [route-map WORD ]

no neighbor { A.B.C.D | X:X::X:X | String } **default-originate ** [route- map WORD ]

[Purpose]

Advertise a default route to a specified peer

[Parameter]

Parameter	Description
A.B.C.D	Neighbor address
X:X::X:X	Neighbor IPv6 address
String	Peer-group name
WORD	Route-map name

[View]

IP address-family view

[Use Cases]

sonic# configure terminal
sonic(config)# router bgp 65100
sonic(config-router)# address-family ipv4 unicast
sonic(config-router-af)# neighbor 1.1.1.1 default-originate route-map test

neighbor next-hop-self

[Command]

neighbor { A.B.C.D | X:X::X:X | String } next-hop-self [force]

no neighbor { A.B.C.D | X:X::X:X | String } next-hop-self [force]

[Purpose]

When announcing routes to IBGP peers or peer groups, set the next hop attribute to the local IP address

[Parameter]

Parameter	Description
A.B.C.D	Neighbor address
X:X::X:X	Neighbor IPv6 address
String	Interface name or neighbor tag
Force	If the optional keyword force is specified, the modification is done also for routes learned via IBGP

[View]

IP address-family view

[Usage Scenario] By default, when a device learns routes from its EBGP neighbors and forwards them to its IBGP neighbors, it does not modify the next-hop IP address of the routes. As a result, the next hop of the route remains the Neighbor address of the EBGP neighbor. When IBGP neighbors receive these routes, they become unusable because the next hop is unreachable. To avoid this situation, you can resolve it by configuring the “next-hop-self” command.

[Use Cases]

sonic# configure terminal
sonic(config)# router bgp 65100
sonic(config-router)# address-family ipv4 unicast
sonic(config-router-af)# neighbor 1.1.1.1 next-hop-self force

neighbor prefix-list

[Command]

neighbor { A.B.C.D | X:X::X:X | String } prefix-list NAME [in|out]

no neighbor { A.B.C.D | X:X::X:X | String } prefix-list NAME [in|out]

[Purpose]

Apply a prefix-list on the neighbor

[Parameter]

Parameter	Description
A.B.C.D	Neighbor address
X:X::X:X	Neighbor IPv6 address
String	Interface name or neighbor tag
NAME	prefix-list name

[View]

IP address-family view

[Use Cases]

sonic# configure terminal
sonic(config)# router bgp 65100
sonic(config-router)# address-family ipv4 unicast
sonic(config-router-af)# neighbor 1.1.1.1 prefix-list test in

neighbor route-reflector-client

[Command]

neighbor { A.B.C.D | X:X::X:X | String } route-reflector-client

no neighbor { A.B.C.D | X:X::X:X | String } route-reflector-client

[Purpose]

Configure the current device as a route reflector when establishing a BGP connection with the specified neighbor

[View]

IP address-family view

[Usage Scenario] To ensure connectivity between IBGP peers, it’s necessary to establish full mesh connections between IBGP peers. However, when there are many IBGP peers, this consumes significant network and CPU resources. Utilizing route reflectors can address this issue by allowing BGP routers to establish connections only with a few route reflectors instead of all other routers.

[Use Cases]

sonic# configure terminal
sonic(config)# router bgp 65100
sonic(config-router)# address-family ipv4 unicast
sonic(config-router-af)# neighbor 1.1.1.1 route-reflector-client

neighbor route-map

[Command]

neighbor { A.B.C.D|X:X::X:X | String } route-map NAME [in|out]

no neighbor { A.B.C.D | X:X::X:X | String } route-map NAME [in|out]

[Purpose]

Apply a route-map on the neighbor

[Parameter]

Parameter	Description
A.B.C.D	Neighbor address
X:X::X:X	Neighbor IPv6 address
String	Peer-group name
NAME	route-map name

[View]

IP address-family view

[Use Cases]

sonic# configure terminal
sonic(config)# router bgp 65100
sonic(config-router)# address-family ipv4 unicast
sonic(config-router-af)# neighbor 1.1.1.1  route-map test in

neighbor send-community

[Command]

neighbor { A.B.C.D | X:X::X:X | String } send-community [both|all|extended|standard|large]

no neighbor { A.B.C.D | X:X::X:X | String } send- community [both|all|extended|standard|large]

[Purpose]

Set the route’community for the neighbor.

[Parameter]

Parameter	Description
A.B.C.D	Neighbor address
X:X::X:X	Neighbor IPv6 address
String	Peer-group name
both	Send both standard and extended community attributes
all	Send both standard, extended and large community attributes
extended	Send extended community attributes
standard	Send standard community attributes
large	Send large community attributes

[View]

IP address-family view

[Use Cases]

sonic# configure terminal
sonic(config)# router bgp 65100
sonic(config-router)# address-family ipv4 unicast
sonic(config-router-af)# neighbor 1.1.1.1 send-community extended

neighbor shutdown

[Command]

neighbor { A.B.C.D | X:X::X:X | String } **shutdown ** [[message MSG ] |[rtt rtt [count count ]]]

no neighbor { A.B.C.D | X:X::X:X | String } **shutdown ** [[message MSG ] ||[rtt rtt [count count ]]]

[Purpose]

Shutdown the peer.

[Parameter]

Parameter	Description
A.B.C.D	Neighbor address
X:X::X:X	Neighbor IPv6 address
String	Interface name or neighbor tag
MSG	Shutdown message
rtt	Round-trip-time in milliseconds (1..65535)
count	Specify the number of keepalives before shutdown

[View]

BGP configuration view

[Use Cases]

sonic# configure terminal
sonic(config)# router bgp 65100
sonic(config-router)# neighbor 1.1.1.1 shutdown message testing

neighbor ttl-security hops

[Command]

neighbor { A.B.C.D | X:X::X:X | String } ttl-security hops NUMBER

no neighbor { A.B.C.D | X:X::X:X | String } ttl-security hops NUMBER

[Purpose]

This command enforces Generalized TTL Security Mechanism (GTSM), as specified in RFC 5082.

[Parameter]

Parameter	Description
A.B.C.D	Neighbor address
X:X::X:X	Neighbor IPv6 address
String	Interface name or neighbor tag
NUMBER	Number of hops to BGP peer (1..254)

[View]

BGP configuration view

[Notes] With this command, only neighbors that are the specified number of hops away will be allowed to become neighbors. This command is mutually exclusive with ebgp-multihop.

[Use Cases]

sonic# configure terminal
sonic(config)# router bgp 65100
sonic(config-router)# neighbor 1.1.1.1 ttl-security hops 2

neighbor weight

[Command]

neighbor { A.B.C.D | X:X::X:X | String } weight WEIGHT

no neighbor { A.B.C.D | X:X::X:X | String } weight WEIGHT

[Purpose]

This command specifies a default weight value for the neighbor’s routes.

[Parameter]

Parameter	Description
A.B.C.D	Neighbor address
X:X::X:X	Neighbor IPv6 address
String	Interface name or neighbor tag
WEIGHT	Weight (0..65535)

[View]

IP address-family view

[Use Cases]

sonic# configure terminal
sonic(config)# router bgp 65100
sonic(config-router)# address-family ipv4 unicast
sonic(config-router-af)# neighbor 1.1.1.1 weight 2

neighbor interface

[Command] neighbor { ethernet | link-aggregation | vlan } ID interface no neighbor { ethernet | link-aggregation | vlan } ID interface

[Purpose] Establish BGP connections using the interface’s IPv6 link-local address.

[Parameter]

Parameter	Description
ID	interface id/link-aggregation id/ vlan id

[View] BGP config view、IP address-family view

[Notes] To use this command, first enable ipv6 use-link-local on the relevant interface. Configuring a BGP peer this way is equivalent to using the neighbor [ip-address] command and supports all the same command-line options.

[Use Cases]

sonic# configure terminal
sonic(config)# router bgp 65100
sonic(config-router)# neighbor ethernet 1 interface remote-as 200
sonic(config-router-af)# address-family ipv4 unicast
sonic(config-router-af)# neighbor ethernet 1 activate