Hi Job ,all > From: Job Snijders [mailto:j...@ntt.net] > Sent: Thursday, June 22, 2017 10:47 PM
[...] > the place where the low local preference is set > should move closer to the initiator of the gshut. Instead of setting > the low LP on Adj-RIB-Out to IBGP neighbors, the low LP should be set > during application of the local policy on the relevant Adj-RIB-In. Current version of the draft changes the LOCAL_PREF on the Adj-RIB-Out and not on the Loc_RIB. This has a technical benefit as otherwise, the router may (locally) select a backup route which it is not allowed to advertise, which would trigger the sending of a withdraw of the original route. i.e. not a g-shut. This may be considered as a corner case, but I don't see why we would choose not cover it. I suppose that one can also see some operational drawbacks: a) seems less intuitive. b) traffic received from external interfaces on this specific g-shut router (the egress in the AS) are forwarded on the "nominal"/g-shut path, rather than on the backup path. IMO: - "a" is not a big concern as the related configuration is pre-configured once for all on the router. We are not discussing the configuration applied at maintenance time. - "b" has no impact on the customer loss of connectivity as this traffic may be locally rerouted in no time (up to zero packet loss) by the router which needs to update its FIB "in place". i.e. the destination IP prefix is never removed from the FIB. Only the outgoing interface is changed, and during this change, both outgoing interfaces are valid (both the old and the new). So although some may see a tradeoff, I'd rather favor the generality of the mechanism. Specifically as not covering the corner cases may surprise the operator. Thanks, Regards, --Bruno _________________________________________________________________________________________________________________________ Ce message et ses pieces jointes peuvent contenir des informations confidentielles ou privilegiees et ne doivent donc pas etre diffuses, exploites ou copies sans autorisation. Si vous avez recu ce message par erreur, veuillez le signaler a l'expediteur et le detruire ainsi que les pieces jointes. Les messages electroniques etant susceptibles d'alteration, Orange decline toute responsabilite si ce message a ete altere, deforme ou falsifie. Merci. This message and its attachments may contain confidential or privileged information that may be protected by law; they should not be distributed, used or copied without authorisation. If you have received this email in error, please notify the sender and delete this message and its attachments. As emails may be altered, Orange is not liable for messages that have been modified, changed or falsified. Thank you. _______________________________________________ GROW mailing list GROW@ietf.org https://www.ietf.org/mailman/listinfo/grow
