Routing device declares its own capabilities. However, when the routing device receives a connection from the peerĪnd an Open message, it replies with another BGP Open message. Once you configure the routing device toīe passive, the routing device does not originate the TCP connection. When a session is passive, the routing device does not send This example focuses on the EBGP case,īut the same workaround works for the RR case. The way to prevent these unnecessary session flaps is to configureĪn extra RR client or EBGP session as a passive session with a neighborĪddress that does not exist. In the master instance for a VPN NLRI family causes the table advertisement The first EBGP session or removing the EBGP session from the configuration Non-RR or the reverse (by adding or removing the cluster statement) causes the table advertisement change. Related to the VPN NLRI family are brought down to implement the tableĪdvertisement change for the VPN NLRI family. VPN network layer reachability information (NLRI) families. Although this example focuses on the family inet-vpn unicast statement, the concept applies to all (or the reverse), all sessions over which VPN routes are exchanged Needing two copies of a route to not needing two copies of a route When, because of a configuration change, BGP transitions from That should be advertised to inet.0 so that they are advertised. ![]() ![]() In Junos OS, a route is only exported one time from one routing tableĪs a primary route to another routing table as a secondary route.īecause the route in instance.inet.0 is alreadyĪ secondary route, it is not allowed to be moved again to the bgp.l3vpn.0 Route in instance.inet.0 is a secondary route. Two copies of the route are needed to enable best-route selection.Ī PE router might receive the same VPN route from a CE device and Then BGP exports the routes to other PE routers. The instance.inet.0 table to the bgp.l3vpn.0 Has an EBGP peer or RR clients, BGP first exports the VPN routes from If BGP does need to propagate VPN routes because the session The creation of two copies of many routes (one in the instance.inet.0 table and one in the bgp.l3vpn.0 table). This behavior is efficient in that it avoids Session has no EBGP peer and no RR clients, BGP exports VPN routesĭirectly from the instance.inet.0 routing table If BGP does not need to propagate VPN routes because the The reason for the flapping behavior is related to BGP operationīGP has the following two modes of operation with respect Is configured, a flap of either the RR IBGP session or the EBGP sessionĬauses flaps of all other BGP sessions that are configured with the family inet-vpn unicast statement. Reflector (RR) or an AS boundary router (an external BGP peer) andĪ VPN family (for example, the family inet-vpn unicast statement) When a router or switch is configured as either a route Sessions on the routing device are dropped and then reestablished. If you change the address family specified in the hierarchy level, all current BGP Such as renaming a BGP group, resets the BGP sessions. Group with the same AS number, all BGP sessions in the IBGP groupĪnd the new route reflector group are reset.Ĭhanging configuration statements that affect BGP peers, Sessions are contained in the same group.Ĭreating a new route reflector-If you have an internalīGP (IBGP) group with an AS number and create a new route reflector Same autonomous system (AS) number with the group where you add theĬluster ID, all BGP sessions are reset regardless of whether the BGP Same routing device, the following modifications to the route reflectionĬonfiguration cause current BGP sessions to be reset:Īdding a cluster ID-If a BGP session shares the If you configure both route reflection and VPNs on the ![]() To be reset (dropped and then reestablished). Certain configuration actions and events cause BGP sessions
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