I have reviewed this document as part of the security directorate's
ongoing effort to review all IETF documents being processed by the IESG.
These comments were written primarily for the benefit of the  security
area directors.  Document editors and WG chairs should treat  these
comments just like any other last call comments.

The summary of the review is Ready.

(note I am a tourist in the BGP area)

This document basically states that people doing network maintenance so often make mistakes that leak into the global BGP table, that it would be a good idea to just firewall all the BGP traffic going out of your network edge as a preventive measure. It's a sad state of software/firmware that an external firewalling process is deemed necessary to properly (re)configure BGP.

This document has an empty Security Considerations section. As this BCP document is basically a "cut yourself off the internet while doing maintenance" I agree that there is basically nothing worse that could happen other then not doing this RFC BCP and then leaking faulty BGP information onto the public internet. One could add something like "don't forget to delete the firewall rules afterwards" or "be sure to use ipv4 and ipv6 rules to prevent BGP leaks", but then again this whole band aid RFC is meant for people who apparently have shown an inability of properly executing RFC's anyway, and this document just tries to convince them to only cut themselves, and not everyone else.