Hi Paul > -----Original Message----- > From: Paul Jakma [mailto:[email protected]] > Sent: Tuesday, November 03, 2015 1:53 AM > To: Andrew Qu > Cc: J Yu; Jacqueline Yu; Martin Winter; [email protected] > Subject: RE: [quagga-dev 13461] Re: Kernel routes does not get updated > when neighbor remove the "next-hop-self" configuration > > On Mon, 2 Nov 2015, Andrew Qu wrote: > > > Hi Paul, > > > > I have a concern about your fix. > > > > In the case of ECMP, your fix will completely remove the FIB entry > > which will cause the complete removal of the FIB entry in hardware > and > > cause the traffic dropped if there is no default network till the new > > update of the same FIB entry arries. > > Hmm, can you expand? > > This fix is to remove the prefix from the zebra RIB, if bgpd has > decided the route is no longer valid and must be withdrawn from zebra. > Jacqueline's fix does this too, doesn't it? > > If the route is still valid, bgpd will still just update it with zebra > accordingly (which should also work for the BGP multi-path case, AFAICT, > but can't test). > > This shouldn't interfere with non-BGP routes. > > Or am I missing something?
Sorry, I miss-read the code path. Your fix has nothing to do with the case I have in mind. And Martin confirmed that there is no issue in the iBGP mpath in terms of per-path withdraw behavior. So there is no concern from me. Thanks for clarifying this. Andrew > > > The ideal fix of this problem should be just deleting the path of a > > FIB entry which should be modified, not the FIB entry if there are > > valid alternative paths. > > In this case, what happens is that: > > - bgpd receives an UPDATE of a route, with an implicit withdraw of the > prior path. > > - in the normal course of things, bgpd just updates the zebra RIB > accordingly (with implicit withdraw of the previous route). > > - if the new path turns out to be invalid (e.g. nexthop doesn't > resolve), > the route stays in the BGP RIB, however it must be deleted from the > zebra RIB. > > There isn't a difference approach, other than that Jacqueline's patch > sends the old next-hop to ensure it matches, and mine doesn't. It just > unconditionally deletes the BGP route for the prefix. The net intended > effect, in both fixes, is that the BGP route is gone from zebra, or not? > > > I may be wrong, but it seems to me that at least Jacueline's fix is > > more toward the optimal fix if it is not THE right fix. > > Stashing references to the old, implicitly withdrawn, no longer valid, > BGP attribute set in the new route just doesn't quite do it for me. > It's another thing to leak or get wrong. > > Perhaps I've misunderstood though? > > regards, > -- > Paul Jakma [email protected] @pjakma Key ID: 64A2FF6A > Fortune: > The biggest difference between time and space is that you can't reuse > time. > -- Merrick Furst ************* Email Confidentiality Notice ******************** The information contained in this e-mail message (including any attachments) may be confidential, proprietary, privileged, or otherwise exempt from disclosure under applicable laws. It is intended to be conveyed only to the designated recipient(s). Any use, dissemination, distribution, printing, retaining or copying of this e-mail (including its attachments) by unintended recipient(s) is strictly prohibited and may be unlawful. If you are not an intended recipient of this e-mail, or believe that you have received this e-mail in error, please notify the sender immediately (by replying to this e-mail), delete any and all copies of this e-mail (including any attachments) from your system, and do not disclose the content of this e-mail to any other person. Thank you! _______________________________________________ Quagga-dev mailing list [email protected] https://lists.quagga.net/mailman/listinfo/quagga-dev
