The user of an Alcatel-Lucent 7750 SR wants to see the effect of changing an import policy immediately. What is the best command to force re-evaluation of the import policy with minimal impact?

The clear router bgp neighbor soft-inbound command is the most appropriate and least disruptive method to re-evaluate a modified BGP import policy on a Nokia 7750 SR. This command leverages the BGP Route Refresh capability (RFC 2918) to request the neighbor to resend its routing updates. The local router then re-processes these updates against the new import policy without resetting the BGP session, thus having a minimal impact on network stability and traffic flow.

A. Configure router bgp shutdown: This command tears down the BGP session entirely. While re-establishing the session would re-evaluate the policy, it is highly disruptive and not a minimal impact solution.
B. Clear router bgp neighbor soft: This command triggers a soft reset for both inbound and outbound policies. Since the goal is only to re-evaluate the import policy, soft-inbound is more specific and has a more minimal impact.
D. Clear router bgp protocol: This command resets the entire BGP protocol instance, dropping all BGP sessions and clearing all BGP routes. This is the most disruptive option and is incorrect.

1. Nokia 7750 SR OS R21.10.R1 Router Configuration Guide, Section: BGP Command Reference.

Page 1018, clear router bgp neighbor command description: The guide details the soft-inbound parameter, stating it "Resets the BGP connection softly for the specified BGP neighbor for the inbound direction only. This option re-applies import policies without resetting the BGP session." This directly supports option C as the correct method for re-evaluating import policies with minimal impact.

2. Nokia 7750 SR OS R21.10.R1 CLI Command Reference, Section: clear commands.

Under clear>router>bgp>neighbor: The documentation explicitly differentiates between soft (for both directions) and soft-inbound (for import policy re-evaluation only). It confirms that soft-inbound is the most precise command for the user's requirement, avoiding unnecessary re-evaluation of export policies. This reinforces why option B is less optimal than C.