Default external BGP route propagation behavior without policies

A newly created or existing BGP instance, group, or EBGP neighbor in a classic interface (the classic CLI and SNMP) maintains backwards compatibility with the insecure default to advertise and receive all routes. It is not compliant with RFC 8212. The secure default behavior must be enabled using the ebgp-default-reject-policy command in these cases.

A newly created BGP instance, group, or EBGP neighbor in a model-driven interface (the MD-CLI, NETCONF, or gRPC) applies the secure default behavior to reject all routes. It is compliant with RFC 8212. The secure behavior can be disabled using the ebgp-default-reject-policy command. However, Nokia recommends configuring import and export policies that express the intended routing instead of using the insecure default behavior. Defining an empty policy does not match any routes, an accept must match the route through an action accept or default-action accept statement.

The default behavior is inherited from the BGP instance to the group to an EBGP neighbor.

The import and export policies that are applied can be displayed using info detail or the show router bgp neighbor commands.

Table: Default EBGP route propagation behavior shows the default EBGP route propagation behavior according to how the neighbor was configured.

Table: Default EBGP route propagation behavior
Management-interface configuration-mode Classic Mixed Model-driven
BGP instance, group, or EBGP neighbor Configured in a classic interface Configured in a classic interface Configured in a model-driven interface Configured in a model-driven interface

Configured before Release 19.5.R1

Default accept

Default accept

Default accept

Default accept

Configured in Release 19.5.R1 or higher

Default accept

Default accept

Default reject1

Default reject1

ISSU to Release 19.5.R1 or higher

Default accept

Default accept

According to rows 1 and 21

According to rows 1 and 21

Reboot with Release 19.5.R1 or higher

Default accept

Default accept

According to rows 1 and 21

Default reject1

Caution: Configuration in model-driven management-interface configuration-mode made before Release 19.5.R1 changes from default accept to default reject if the router is rebooted with Release 19.5.R1 or higher. Configuration in classic or mixed mode maintains the existing default accept behavior.
1 Indicates a default behavior change