6.9. BGP Command Reference

This command enables the BGP protocol instance and BGP configuration context. BGP is administratively enabled upon creation.

The no form of this command deletes the BGP protocol instance and removes all configuration parameters for the BGP instance. BGP must be shutdown before deleting the BGP instance. An error occurs if BGP is not shutdown first.

This command enables the add-paths configuration context and enables add-paths to be configured for one or more BGP route types. The BGP add-paths capability allows the router to send and receive multiple paths per prefix to and from a peer.

The no form of this command (no add-paths) removes add-paths from the configuration of BGP, the group, or the neighbor, causing sessions established using add-paths to go down and come back up without the add-paths capability.

This command configures the add-paths capability for IPv4 routes. By default, the add-paths capability is disabled for IPv4 routes.

Note: Add-paths are supported only for the label-IPv4 family.

The maximum number of paths to send per IPv4 NLRI is the configured send-limit, which is a mandatory parameter. The capability to receive multiple paths per prefix from a peer is configurable using the optional receive keyword. If the receive keyword is not included in the command, the receive capability is enabled by default.

The no form of this command disables add-paths support for IPv4 routes, causing sessions established using add-paths for IPv4 to go down and come back up without the add-paths capability.

This command configures the add-paths capability for IPv6 routes. By default, the add-paths capability is disabled for IPv6 routes.

Note: Add-paths are supported only for the label-IPv4 family.

The maximum number of paths to send per IPv6 NLRI is the configured send-limit, which is a mandatory parameter. The capability to receive multiple paths per prefix from a peer is configurable using the optional receive keyword. If the receive keyword is not included in the command, the receive capability is enabled by default.

The no form of this command disables add-paths support for IPv6 routes, causing sessions established using add-paths for IPv6 to go down and come back up without the add-paths capability.

This command configures the add-paths capability for VPN-IPv4 routes. By default, add-paths is not enabled for VPN-IPv4 routes.

The maximum number of paths per VPN-IPv4 NLRI to send is the configured send-limit, which is a mandatory parameter. The capability to receive multiple paths per prefix from a peer is configurable using the optional receive keyword. If the receive keyword is not included in the command, the receive capability is enabled by default.

The no form of this command disables add-paths support for VPN-IPv4 routes, causing sessions established using add-paths for VPN-IPv4 to go down and come back up without the add-paths capability.

This command configures the add-paths capability for VPN-IPv6 routes. By default, add-paths is not enabled for VPN-IPv6 routes.

The maximum number of paths per VPN-IPv6 NLRI to send is the configured send-limit, which is a mandatory parameter. The capability to receive multiple paths per prefix from a peer is configurable using the optional receive keyword. If the receive keyword is not included in the command the receive capability is enabled by default.

The no form of this command disables add-paths support for VPN-IPv6 routes, causing sessions established using add-paths for VPN-IPv6 to go down and come back up without the add-paths capability.

This command enables the advertising of inactive BGP routes to other BGP peers. By default, BGP only advertises BGP routes to other BGP peers if a specific BGP route is chosen by the route table manager as the most preferred route within the system and is active in the forwarding plane. This command allows system administrators to advertise a BGP route even though it is not the most preferred route within the system for a specific destination.

The no form of this command disables the advertising of inactive BGP routers to other BGP peers.

This command configures the IPv4 or IPv6 transport peers to exchange RFC 3107-labeled IPv4 or IPv6 routes.

If IPv4 is enabled, all IPv4 routes advertised to the remote BGP peer are sent with an RFC 3107-formatted label for the destination route.

If IPv6 is enabled, all IPv6 routes advertised to the remote BGP peer are sent with an RFC 3107-formatted label for the destination route.

The optional use-svc-routes parameter limits the number of BGP 3107 IPv4 labeled routes that are installed in the MPLS FIB. If this parameter is specified, only those BGP 3107 labeled routes that are required by services or required for establishing a BGP session with a configured neighbor are installed in the MPLS FIB. The following conditions trigger the installation of the MPLS label into the MPLS FIB for the received BGP 3107 IPv4 labeled route:

The no form of this command disables all configured options.

This command sets the router ID in the BGP aggregator path attribute to zero when BGP aggregates routes. This prevents different routers within an AS from creating aggregate routes that contain different AS paths.

When BGP is aggregating routes, it adds the aggregator path attribute to the BGP update messages. By default, BGP adds the ASN and router ID to the aggregator path attribute.

When this command is enabled, BGP adds the router ID to the aggregator path attribute. This command is used at the group level to revert to the value defined under the global level, while this command is used at the neighbor level to revert to the value defined under the group level.

The no form of this command used at the global level reverts to default where BGP adds the ASN and router ID to the aggregator path attribute.

The no form of this command used at the group level reverts to the value defined at the global level.

The no form of this command used at the neighbor level reverts to the value defined at the group level.

This command enables accumulated Interior Gateway Protocol (AIGP) path attribute support with one or more BGP peers. BGP path selection among routes with an associated AIGP metric is based on the end-to-end IGP metrics of the different BGP paths, even when these BGP paths span more than one AS and IGP instance.

The no form of this command disables AIGP path attribute support, removes the AIGP attribute from advertised routes, and causes the AIGP attribute in received routes to be ignored.

This command configures a TCP authentication keychain to use for the session. The keychain allows the rollover of authentication keys during the lifetime of a session.

This command configures the BGP authentication key.

Authentication is performed between neighboring routers before setting up the BGP session by verifying the password. Authentication is performed using the MD-5 message based digest.

The no form of this command reverts to the default value.

This command enables the computation and use of a backup path for labeled IPv4 BGP-learned prefixes belonging to the base router. Multiple paths must be received for a prefix to take advantage of this feature. When a prefix has a backup path and its primary paths fail, the affected traffic is rapidly diverted to the backup path without waiting for control plane reconvergence to occur. When many prefixes share the same primary paths, and in some cases also the same backup path, the time to failover traffic to the backup path is independent of the number of prefixes.

By default, IPv4 prefixes do not have a backup path installed in the IOM.

The no form of this command disables the use of a backup path.

This command enables path selection configuration.

This command configures the comparison of BGP routes based on the Multi-Exit Discriminator (MED) path attribute.

The default behavior of 7210 SAS (equivalent to the no form of this command) is to only compare two routes on the basis of MED if they have the same neighbor AS (the first non-confed AS in the received AS_PATH attribute). Also by default, a route without a MED attribute is handled the same as though it had a MED attribute with the value 0.

This command without the strict-as keyword allows MED to be compared even if the paths have a different neighbor AS; in this case, if neither the zero nor infinity keyword is specified, the zero option is inferred, meaning a route without a MED is handled as though it had a MED attribute with the value 0. When the strict-as keyword is present, MED is only compared between paths from the same neighbor AS; in this case, zero or infinity is mandatory and tells BGP how to interpret paths without a MED attribute.

The no form of this command only compares two routes on the basis of MED if they have the same neighbor AS.

This command specifies whether the AS path is used to determine the best BGP route.

If this command is enabled, the AS paths of incoming routes are not used in the route selection process.

The no form of this command removes the parameter from the configuration.

This command configures BGP to disregard the resolved distance to the BGP next hop in its decision process for selecting the best route to a destination.

When configured in the config>router>bgp>best-path-selection context, this command applies to the comparison of two BGP routes with the same NLRI learned from base router BGP peers. When configured in the config>service>vprn context, this command applies to the comparison of two BGP-VPN routes for the same IP prefix imported into the VPRN from the base router BGP instance. When configured in the config>service>vprn>bgp>best-path-selection context, this command applies to the comparison of two BGP routes for the same IP prefix learned from VPRN BGP peers.

The no form of this command reverts to the default behavior whereby BGP factors the distance to the next hop into its decision process.

This command modifies the route selection behavior.

When the this command is enabled and the current best path to a destination was learned from eBGP peer X with BGP identifier x, new paths that are received from eBGP peer Y with BGP identifier y and are equivalent will not change the best path even if y is less than x during BGP identifier comparison.

The no form of this command reverts to the default behavior of selecting the route with the lowest BGP identifier (y) as best.

This command configures the cluster ID for a route reflector server.

Route reflectors reduce the number of iBGP sessions required within an AS. Normally, all BGP speakers within an AS must have a BGP peering with every other BGP speaker in an AS. A route reflector and its clients form a cluster. Peers that are not part of the cluster are considered to be non-clients.

When a route reflector receives a route, it must first select the best path from all the paths received. If the route was received from a non-client peer, the route reflector sends the route to all clients in the cluster. If the route came from a client peer, the route reflector sends the route to all non-client peers and to all client peers except the originator.

For redundancy, a cluster can have multiple route reflectors.

The no form of this command deletes the cluster ID and disables the route reflection at the global BGP level or for the specified group or neighbor.

This command configures the BGP connect retry timer value.

When this timer expires, BGP tries to reconnect to the configured peer. This configuration parameter can be set at three levels: global level (applies to all peers), peer-group level (applies to all peers in group) or neighbor level (only applies to specified peer). The most specific value is used.

The no form of this command used at the global level reverts to the default value.

The no form of this command used at the group level reverts to the value defined at the global level.

The no form of this command used at the neighbor level reverts to the value defined at the group level.

This command enables BGP route damping for learned routes that are defined within the route policy. Use damping to reduce the number of update messages sent between BGP peers and reduce the load on peers without affecting the route convergence time for stable routes. Damping parameters are set through route policy definition.

The no form of this command used at the global level reverts route damping.

The no form of this command used at the group level reverts to the value defined at the global level.

The no form of this command used at the neighbor level reverts to the value defined at the group level.

When damping is enabled and the route policy does not specify a damping profile, the default damping profile is used. This profile is always present and consists of the following parameters:

This command enables a text description stored in the configuration file for a configuration context.

The no form of this command removes the description string from the context.

This command disables the use of 4-byte ASNs. It can be configured at all three level of the hierarchy so it can be specified down to the per peer basis.

If this command is enabled, 4-byte ASN support should not be negotiated with the associated remote peers.

The no form of this command reverts to the default behavior, which is to enable the use of 4-byte ASN.

This command disables the exchange of capabilities when the command is enabled. After the peering is flapped, any new capabilities are not negotiated and strictly support IPv4 routing exchanges with that peer.

The no form of this command removes this command from the configuration and reverts to the default behavior.

This command disables the reflection of routes by the route reflector at the BGP, group, or neighbor level.

This command only disables the reflection of routes from other client peers. Routes learned from non-client peers are still reflected to all clients.

The no form of this command re-enables client reflection of routes.

This command configures BGP to disable sending communities.

This command configures BGP fast external failover.

This command enables the use of the IGP next hop to the BGP next hop as the next hop of last resort.

This command enables BGP peer tracking. BGP peer tracking allows a BGP peer to be dropped immediately if the route used to resolve the BGP peer address is removed from the IP routing table, and there is no alternative available. The BGP peer does not wait for the hold timer to expire; therefore, the BGP reconvergence process is accelerated.

The no form of this command disables peer tracking.

This command enables a route reflector of VPN-IP routes to be deployed in the data path between two BGP peers (a peer X and a peer Y) in a next-hop resolution.

Note: Scaling and convergence should be considered before enabling this command.

When this command is configured, all received VPN-IP routes, regardless of route target, are imported into the dummy VRF, where the BGP next hops are resolved. The label-route-transport-tunnel command in the config>router>bgp>next-hop-resolution context determines what types of tunnels are eligible to resolve the next hops.

If a received VPN-IP route from iBGP peer X is resolved and selected as best so that it can be readvertised to an iBGP peer Y, and the BGP next hop is modified toward peer Y (by using the next-hop-self command in the Y group or neighbor context, or by using the next-hop action command in an export policy applied to Y), BGP allocates a new VPN service label value for the route, signals that new label value to Y, and programs the IOM to do the corresponding label swap operation. The supported combinations of X and Y are the following:

The no form of this command causes the route to be readvertised without a new service label, or a new service label to not be advertised between the two peers.

This command specifies the export route policy used to determine which routes are advertised to peers. Route policies are configured in the config>router>policy-options context.

This configuration parameter can be set at three levels: global level (applies to all peers), group level (applies to all peers in peer-group), or neighbor level (only applies to specified peer). The most specific level is used.

When multiple policy names are specified, the policies are evaluated in the order they are specified. A maximum of 15 policy names can be configured. The first policy that matches is applied.

When multiple export commands are issued, the last command entered overrides the previous command.

When no export policies are specified, BGP routes are advertised and non-BGP routes are not advertised by default.

The no form of this command removes the policy association with the BGP instance. To remove association of all policies, use the no export command without arguments.

This command specifies the address family or families to be supported over BGP peerings in the base router. This command is additive so entering the family command adds the specified address family to the list.

The no form of this command removes the specified address family from the associated BGP peerings. If an address family is not specified, reset the supported address family back to the default.

This command enables the use of split horizon. Split horizon prevents routes from being reflected back to a peer that sends the best route. It applies to routes of all address families and to eBGP or iBGP sending peers.

The no form of this command means that no effort is taken to prevent a best route from being reflected back to the sending peer.

This command causes the base instance BGP export route policies to be applied to VPN-IPv4 routes.

The no form of this command disables the application of the base instance BGP route policies to VPN-IPv4 routes.

This command causes the base instance BGP import route policies to be applied to VPN-IPv4 routes.

The no form of this command disables the application of the base instance BGP import route policies to VPN-IPv4 routes.

This command enables the context to configure a BGP peer group.

The no form of this command deletes the specified peer group and all configurations associated with the peer group. The group must be shutdown before it can be deleted.

This command configures the BGP hold time, expressed in seconds.

The BGP hold time specifies the maximum time BGP waits between successive messages (either keepalive or update) from its peer, before closing the connection. This configuration parameter can be set at three levels: global level (applies to all peers), group level (applies to all peers in group), or neighbor level (only applies to specified peer). The most specific value is used.

Even though the 7210 SAS implementation allows setting the keepalive time separately, the configured keepalive timer is overridden by the hold-time value under the following circumstances.

The no form of this command used at the global level reverts to the default value.

The no form of this command used at the group level reverts to the value defined at the global level.

The no form of this command used at the neighbor level reverts to the value defined at the group level.

This command specifies the import route policy to use to determine which routes are accepted from peers. Route policies are configured in the config>router>policy-options context.

This configuration parameter can be set at three levels: global level (applies to all peers), group level (applies to all peers in peer-group), or neighbor level (only applies to specified peer). The most specific level is used.

When multiple policy names are specified, the policies are evaluated in the order they are specified. A maximum of 15 policy names can be specified. The first policy that matches is applied.

When multiple import commands are issued, the last command entered overrides the previous command.

When an import policy is not specified, BGP routes are accepted by default.

The no form of this command removes the policy association with the BGP instance. To remove association of all policies, use no import without arguments.

This command configures the BGP keepalive timer. A keepalive message is sent every time this timer expires.

The keepalive parameter can be set at three levels: global level (applies to all peers), group level (applies to all peers in peer-group), or neighbor level (only applies to specified peer). The most specific value is used.

The keepalive value is generally one third of the hold-time interval. The 7210 SAS implementation allows the keepalive value and the hold-time interval to be independently set; however, under the following circumstances, the configured keepalive value is overridden by the hold-time value.

The no form of this command used at the global level reverts to the default value.

The no form of this command used at the group level reverts to the value defined at the global level.

The no form of this command used at the neighbor level reverts to the value defined at the group level.

This command configures the local IP address used by the group or neighbor when communicating with BGP peers.

Outgoing connections use the local-address as the source of the TCP connection when initiating connections with a peer.

When a local address is not specified, 7210 SAS uses the system IP address when communicating with iBGP peers and uses the interface address for directly connected EBGP peers. This command is used at the neighbor level to revert to the value defined under the group level.

The no form of this command removes the configured local address for BGP.

The no form of this command used at the group level reverts to the value defined at the global level.

The no form of this command used at the neighbor level reverts to the value defined at the group level.

This command configures a BGP virtual autonomous system (AS) number.

In addition to the ASN configured for BGP in the config>router>autonomous-system context, a virtual (local) ASN is configured.The virtual ASN is added to the as-path message before the router ASN makes the virtual AS the second AS in the as-path.

This command can be configured at three levels: global level (applies to all peers), group level (applies to all peers in peer-group), or neighbor level (only applies to specified peer). By specifying this command at each neighbor level, it is possible to have a separate AS number for each eBGP session.

When a command is entered multiple times for the same AS, the last command entered is used in the configuration. Add or remove the private keyword dynamically by reissuing the command.

Changing the local AS at the global level in an active BGP instance causes the BGP instance to restart with the new local ASN. Changing the local AS at the global level in an active BGP instance causes BGP to reestablish the peer relationships with all peers in the group with the new local ASN. Changing the local AS at the neighbor level in an active BGP instance causes BGP to reestablish the peer relationship with the new local ASN.

This is an optional command and can be used in a circumstance like the following example. Provider router P is moved from AS1 to AS2. The customer router that is connected to P, however, is configured to belong to AS1. To avoid reconfiguring the customer router, the local-as value on router P can be set to AS1. Therefore, router P adds AS1 to the as-path message for routes it advertises to the customer router.

The no form of this command used at the global level removes any virtual ASN configured.

The no form of this command used at the group level reverts to the value defined at the global level.

The no form of this command used at the neighbor level reverts to the value defined at the group level.

This command configures the BGP local preference attribute in incoming routes, if not specified, and configures the default value for the attribute.

This command is used if the BGP route arrives from a BGP peer without the local-preference command configured.

The specified value can be overridden by any value set via a route policy. This configuration parameter can be set at three levels: global level (applies to all peers), group level (applies to all peers in peer-group), or neighbor level (only applies to specified peer). The most specific value is used.

The no form of this command at the global level specifies that incoming routes with local-preference set are not overridden, and routes arriving without local-preference set are interpreted as if the route had local-preference value of 100.

The no form of this command used at the group level reverts to the value defined at the global level.

The no form of this command used at the neighbor level reverts to the value defined at the group level.

This command configures how the BGP peer session handles loop detection in the AS path.

This command can be set at three levels: global level (applies to all peers), group level (applies to all peers in peer-group), or neighbor level (only applies to specified peer). The most specific value is used.

Dynamic configuration changes of loop-detect are not recognized.

The no form of this command used at the global level reverts to the default value.

The no form of this command used at the group level reverts to the value defined at the global level.

The no form of this command used at the neighbor level reverts to the value defined at the group level.

This command enables advertising the MED and assigns the value used for the path attribute for the MED advertised to BGP peers if the MED is not already set.

The specified value can be overridden by any value set via a route policy.

This command can be set at three levels: global level (applies to all peers), group level (applies to all peers in peer-group), or neighbor level (only applies to specified peer). The most specific value is used.

The no form of this command used at the global level reverts to default where the MED is not advertised.

The no form of this command used at the group level reverts to the value defined at the global level.

The no form of this command used at the neighbor level reverts to the value defined at the group level.

This command configures the minimum interval at which a path attribute, originated by the local router, can be advertised to a peer.

This command can be set at three levels: global level (applies to all peers), group level (applies to all peers in peer-group), or neighbor level (only applies to specified peer). The most specific value is used.

The no form of this command used at the global level reverts to the default value.

The no form of this command used at the group level reverts to the value defined at the global level.

The no form of this command used at the neighbor level reverts to the value defined at the group level.

This command configures the minimum interval at which a prefix can be advertised to a peer.

This command can be set at three levels: global level (applies to all peers), group level (applies to all peers in peer-group), or neighbor level (only applies to specified peer). The most specific value is used.

The no form of this command used at the global level reverts to default value.

The no form of this command used at the group level reverts to the value defined at the global level.

The no form of this command used at the neighbor level reverts to the value defined at the group level.

When this command is enabled, route refresh messages are not required or issued when VPN route policy changes are made; RIB-IN retains all MP-BGP routes.

The no form of this command disables the feature.

This command configures the time to live (TTL) value entered in the IP header of packets sent to an eBGP peer multiple hops away.

The no form of this command conveys to the BGP instance that the eBGP peers are directly connected.

The no form of this command used at the global level reverts to the default value.

The no form of this command used at the group level reverts to the value defined at the global level.

The no form of this command used at the neighbor level reverts to the value defined at the group level.

This command configures BGP to advertise routes to members of a group or to a specific neighbor using a local address of the BGP instance as the BGP next-hop address. This command is set regardless of the route source (eBGP or iBGP) or its family. When used with VPN-IPv4 and VPN-IPv6 routes, the enable-rr-vpn-forwarding command should also be configured.

The no form of this command uses standard protocol behavior to decide whether to set next-hop-self in advertised routes.

This command enables the context to configure next-hop resolution.

This command enables the context to configure the binding of BGP labeled routes to tunnels.

This command configures the binding of BGP labeled routes to tunnels for a specific family.

This command configures the resolution state of BGP labeled routes using tunnels to BGP peers.

This command enables the context to configure the subset of tunnel types used in the resolution of BGP label routes using tunnels to BGP peers.

This command configures LDP tunneling for next-hop resolution.

This command configures RSVP tunneling for next-hop resolution.

This command selects the SR tunnel type programmed by an IS-IS instance in the TTM for next-hop resolution and specifies SR tunnels (shortest path) to destinations reachable by the IS-IS protocol.

This command allows BGP to use the SR tunnel in the tunnel table submitted by the lowest preference IS-IS instance or, in the case of IS-IS instances with the same lowest preference, the IS-IS instance with the lowest ID number.

This command selects the SR tunnel type programmed by an OSPF instance in the TTM for next-hop resolution and specifies SR tunnels (shortest path) to destinations reachable by the OSPF protocol.

This command allows BGP to use the SR tunnel in the tunnel table submitted by the lowest preference OSPF instance or, in the case of OSPF instances with the same lowest preference, the OSPF instance with the lowest ID number.

This command opens the configuration tree for sending or accepting BGP filter lists from peers (outbound route filtering).

This command enables the context to configure sending or accepting extended-community-based BGP filters.

For the no form of the command to work, all subcommands (send-orf, accept-orf) must be removed first.

This command instructs the router to negotiate the receive capability in the BGP ORF negotiation with a peer and to accept filters that the peer wishes to send.

The no form of this command causes the router to remove the accept capability in the BGP ORF negotiation with a peer and to clear any existing ORF filters that are currently in place.

This command instructs the router to negotiate the send capability in the BGP outbound route filtering (ORF) negotiation with a peer.

This command also causes the router to send a community filter, prefix filter, or AS path filter configured as an inbound filter on the BGP session to its peer as an ORF Action ADD.

The no form of this command causes the router to remove the send capability in the BGP ORF negotiation with a peer.

The no form also causes the router to send an ORF remove action for a community filter, prefix filter, or AS path filter configured as an inbound filter on the BGP session to its peer.

If the comm-id parameters are not exclusively route target communities, the router extracts appropriate route targets and uses those. If the comm-id parameters specified contain no route targets, the router does not send an ORF.

This command creates a BGP peer/neighbor instance within the context of the BGP group.

This command can be issued repeatedly to create multiple peers and their associated configuration.

The no form of this command removes the specified neighbor and the entire configuration associated with the neighbor. The neighbor must be administratively shut down before attempting to delete it. If the neighbor is not shut down, the command does not result in any action except a warning message on the console indicating that the neighbor is still administratively up.

This command configures the AS number for the remote peer. The peer AS number must be configured for each configured peer.

For eBGP peers, the peer AS number configured must be different from the AS number configured for this router under the global level, because the peer will be in a different AS than this router.

For iBGP peers, the peer AS number must be the same as the AS number of this router configured under the global level.

This is a required command for each configured peer. This command can be configured under the group level for all neighbors in a particular group.

This command enables path MTU discovery for the associated TCP connections. In doing so, the MTU for the associated TCP session is initially set to the egress interface MTU. The DF bit is also set so that if a router along the path of the TCP connection cannot handle a packet of a particular size without fragmenting, an ICMP message is sent back to set the path MTU for the specific session to a lower value that can be forwarded without fragmenting.

The no form of this command disables path MTU discovery.

This command configures the route preference for routes learned from the configured peers.

This command can be set at three levels: global level (applies to all peers), group level (applies to all peers in peer-group), or neighbor level (only applies to specified peer). The most specific value is used.

The lower the preference, the higher the chance of the route being the active route. The 7210 SAS assigns BGP routes highest default preference compared to routes that are direct, static, or learned through MPLS or OSPF.

The no form of this command used at the global level reverts to default value.

The no form of this command used at the group level reverts to the value defined at the global level.

The no form of this command used at the neighbor level reverts to the value defined at the group level.

This command configures the maximum time before stale routes are purged.

This command disables the delay (Minimum Route Advertisement) on sending BGP withdrawals. Normal route withdrawals may be delayed up to the minimum route advertisement to allow for efficient packing of BGP updates.

The no form of this command removes this command from the configuration and reverts withdrawal processing to the normal behavior.

This command configures the maximum number of routes BGP can learn from a peer.

When the number of routes reaches 90% of this limit, an SNMP trap is sent. When the limit is exceeded, the BGP peering is dropped and disabled.

The no form of this command removes the configuration.

This command enables private ASNs to be removed from the AS path before advertising them to BGP peers.

When this command is set at the global level, it applies to all peers regardless of group or neighbor configuration. When the command is set at the group level, it applies to all peers in the group regardless of the neighbor configuration.

7210 SAS software recognizes the set of ASNs that are defined by IANA as private. These are ASNs in the range of 64512 through 65535, inclusive.

The no form of this command used at the global level reverts to the default value.

The no form of this command used at the group level reverts to the value defined at the global level.

The no form of this command used at the neighbor level reverts to the value defined at the group level.

This command specifies the router ID to be used with this BGP instance.

Changing the BGP router ID on an active BGP instance causes the BGP instance to restart with the new router ID. The router ID must be set to a valid host address. By default, no router ID is configured for BGP; the system interface IP address is used.

This command administratively disables an entity. When disabled, an entity does not change, reset, or remove any configuration settings or statistics.

The operational state of the entity is disabled as well as the operational state of any entities contained within. Many objects must be shut down before they may be deleted.

Unlike other commands and parameters where the default state is not indicated in the configuration file, the shutdown and no shutdown states are always indicated in system-generated configuration files.

Default administrative states for services and service entities are described in Special Cases.

The no form of this command places an entity in an administratively enabled state.

This command designates the BGP peer as type internal or external.

Specifying the internal parameter type indicates the peer is an iBGP peer; specifying the external parameter type indicates the peer is an eBGP peer.

By default, 7210 SAS derives the type of neighbor based on the local AS specified. If the local AS specified is the same as the AS of the router, the peer is considered internal. If the local AS is different, the peer is considered external.

The no form of this command used at the group level reverts to the default value.

The no form of this command used at the neighbor level reverts to the value defined at the group level.

This command configures the autonomous system number (ASN) for the router. A router can only belong to one AS. An ASN is a globally unique number with an AS. This number is used to exchange exterior routing information with neighboring ASs and as an identifier of the AS.

If the ASN is changed on a router with an active BGP instance, the new AS number is not used until the BGP instance is restarted either by administratively disabling and enabling (shutdown/no shutdown) the BGP instance or rebooting the system with the new configuration.

This command configures the router ID for the router instance.

The router ID is used by both OSPF and BGP routing protocols in this instance of the routing table manager.

When configuring a new router ID, protocols are not automatically restarted with the new router ID. The next time a protocol is initialized, the new router ID is used. This can result in an interim period of time when different protocols use different router IDs.

To force the new router ID to be used, issue the shutdown and no shutdown commands for each protocol that uses the router ID, or restart the entire router.

By default, the system uses the system interface address (which is also the loopback address). If a system interface address is not configured, use the last 32 bits of the chassis MAC address.

The no form of this command to reverts to the default value.

This command displays router instance information.

This command enables the context to display BGP-related information.

This command displays BGP sessions using a particular authentication keychain.

This command displays BGP routes that have been dampened because of route flapping. This command can be entered with or without a route parameter.

When the detail keyword is included, more detailed information displays.

When only the command is entered (without any parameters included except detail), all dampened routes are listed.

When a parameter is specified, the matching route or routes are listed.

When a decayed, history, or suppressed keyword is specified, only those types of dampened routes are listed.

This command displays group information for a BGP peer group. This command can be entered with or without parameters.

When this command is entered without a group name, information about all peer groups displays.

When this command is issued with a specific group name, information only pertaining to that specific peer group displays.

The “State” field displays the BGP group operational state. Valid states are the following:

This command displays BGP neighbor information. This command can be entered with or without parameters.

When this command is issued without any parameters, information about all BGP peers displays.

When the command is issued with a specific IP address or ASN, information regarding only that specific peer or peers with the same AS displays.

When either received-routes or advertised-routes is specified, the routes received from or sent to the specified peer is listed (see second output example).

Note: This information is not available when using SNMP.

When either history or suppressed is specified, the routes learned from those peers that either have a history or are suppressed (respectively) are listed.

The “State” field displays the BGP peer protocol state. In addition to the standard protocol states, this field can also display the “Disabled” operational state, which indicates the peer is operationally disabled and must be restarted.

This command displays BGP next-hop information.

This command displays a summary of BGP path attributes.

This command displays BGP route information.

If this command is issued without any parameters, the entire BGP routing table is displayed.

If this command is issued with an IP prefix/mask or IP address, the best match for the parameter is displayed.

This command displays a summary of BGP neighbor information.

The “State” field displays the global BGP operational state. The valid values are the following:

For example, if a BGP peer is operationally disabled, the state in the summary table shows the state “Disabled.”