Description

This knowledge article explains about the BGP connection attempt made by the unconfigured neighbour 130.16.0.1 that is the FXP interface of a cluster.

 

Symptoms

SRX observes below logs :-

 

rpd[2150]: bgp_listen_accept: Connection attempt from unconfigured neighbor: 130.16.0.1+62937

rpd[2150]: bgp_listen_accept:6432: NOTIFICATION sent to 130.16.0.1+62937 (proto): code 6 (Cease) subcode 5 (Connection Rejected), Reason: Connection attempt from unconfigured neighbor: 130.16.0.1+62937

rpd[2150]: bgp_listen_accept: Connection attempt from unconfigured neighbor: 130.16.0.1+60369

rpd[2150]: bgp_listen_accept:6432: NOTIFICATION sent to 130.16.0.1+60369 (proto): code 6 (Cease) subcode 5 (Connection Rejected), Reason: Connection attempt from unconfigured neighbor: 130.16.0.1+60369

rpd[2150]: bgp_listen_accept: Connection attempt from unconfigured neighbor: 130.16.0.1+53321

rpd[2150]: bgp_listen_accept:6432: NOTIFICATION sent to 130.16.0.1+53321 (proto): code 6 (Cease) subcode 5 (Connection Rejected), Reason: Connection attempt from unconfigured neighbor: 130.16.0.1+53321

rpd[2150]: bgp_listen_accept: Connection attempt from unconfigured neighbor: 130.16.0.1+56130

rpd[2150]: bgp_listen_accept:6432: NOTIFICATION sent to 130.16.0.1+56130 (proto): code 6 (Cease) subcode 5 (Connection Rejected), Reason: Connection attempt from unconfigured neighbor: 130.16.0.1+56130

Solution

When we configure BGP on SRX cluster, BGP listens to all the interfaces/IPs including fxp1 local ip (129.16.0.1 on node0/130.16.0.1 on node1) which is used as control port in SRX cluster.

 

You can verify it by using below command

root@abc-srx3xx% netstat -a -n | grep 179 | grep LISTEN

tcp46 0 0 *.179 *.* LISTEN

tcp4 0 0 *.179 *.* LISTEN

 

Regarding the BGP connection attempt from fxp1 interface, when SRX is configured with the non-stop active routing in routing-option hierarchy,

 

routing-options {

  autonomous-system 65101;

  }

  nonstop-routing; <<<<<-------

}

 

Replication of control packets occurs between the primary and secondary. This is to ensure that the secondary maintains current state information with the primary. We refer to this as JSR socket replication. In addition, with the state list, BGP listens to the secondary via control port as a local active interface. The TCP/BGP packets that are currently visible in that control interface are due to this.

 

NSR (non stop active routing ) is not supported on the SRX platform. In supported platform NSR is used along with GRES (Graceful routing engine switchover).

Nonstop Active Routing System Requirements

 

Fix is to remove the NSR config from the SRX using the below command.

 

#delete routing-options nonstop-routing

#commit

Modification History

2024-05-14 : Article Created