The following BGP events from inventory service are handled as part of event handling.
When router BGP delete message is received, fabric passes through all the IP and EVPN neighbors, peer group tables and the entries corresponding to the device for which router BGP delete message is received and mark the entries as ‘create‘ to configure the router BGP and its related neighbors on the device.
When BGP IP neighbor delete message is received, fabric passes through all the IP neighbors deleted and which exists in fabric database for a given neighbor IP or remote ASN and mark the entries as ‘create‘ to configure the deleted IP neighbors on the device.
When BGP IP neighbor update message is received, fabric passes through all the IP neighbors matching the neighbor IP for the device in the database. If any of the fabric managed attribute in the IP neighbor table is changed, fabric marks the entries as ‘update‘ and pushes the configuration back to the device.
When BGP EVPN neighbor delete message is received, fabric passes through all the EVPN neighbors deleted and which exists in fabric database for a given neighbor IP or remote ASN and mark the entries as ‘create‘ to configure back the deleted EVPN neighbors on the device.
When BGP EVPN neighbor update message is received, fabric passes through all the EVPN neighbors matching the neighbor IP for the device in database. If any of the fabric managed attribute in the EVPN neighbor table is changed, fabric marks the entries as ‘update‘ and pushes the configuration back to the device.
Peer Group Delete message is received only when there are no IP/EVPN neighbors associated with it. If there are no IP/EVPN neighbors associated with it, fabric marks the Peer Group as ‘delete‘.
When Peer group attributes such as BFD and remote ASN change, inventory sends a peer group update message. The fabric processes this message and checks if the peer group exists in the database. If the peer group exists and there are changes to the attributes, the fabric pushes the peer group configuration with fabric intended configuration back to the device.
BGP IP Address Family Delete message is received when the IP address-family for a device is deleted through CLI or out-of-band means. When fabric receives this message, it passes through all the IP neighbors associated with that address-family and marks the entries as ‘create config‘ to restore all the deleted IP neighbors on the device.
BGP EVPN Address Family Delete message is received when the EVPN address-family for a device is deleted through CLI or out-of-band means. When fabric receives the message, it passes through all the EVPN neighbors associated with that address-family and marks the entries as ‘create config‘ to restore all the deleted EVPN neighbors on the device.