Paul, see in-line
On 4/21/2016 4:51 AM, Paul Jakma wrote: > On Wed, 20 Apr 2016, Lou Berger wrote: > >> To up level a moment: to me the most important thing is to keep >> fixes/improvements rolling into the quagga base and not let a single >> patch block overall progress on improving the code base. I liked the >> idea of proposed branches floated awhile back on the list (don't recall >> who sent it) but any approach that brings in patches would be good. > We were doing that. Rounds of integration. > > Kicking off the latest round seems to have stalled. Not sure why. in this week coordination call donald said he'd kick off a bug fix branch and david said he'd start a release branch as soon as he has commit approval (which I believe vincent said he'd approve.) Not sure where they stand on this other than not seeing any new branch on savana. >> the whole project, then I think it's better to accept *something* and >> move on, then to argue about what is *optimal* -- which I think we're >> not going to agree on. > See my reply to Martin. > > If the routing loop issue is serious, then we should take it seriously. I know we disagree on this -- I personally see loops with standard routers as a bigger deal as the loop can introduced on a change on the standard router, while in the quagga only case we can document the issue (either use fffe or the new config option, if present -- not sure where would be the best place, perhaps the ospf manual section?) and inform the quagga users about the risk. > And the prior patch just flips the SPF behaviour and doesn't provide a > config option. So in the interim, it might just increase the number of > networks that see this issue. > > If it's not serious at all, then it still needs config options (first > patch was missing those), I like the config option, but given a choice between conformant and no-config, I'd take the former for the reasons as above. > and also it's worth bearing in mind that H-bit > is on the horizon, and see if we can wait for that. I think is a reasonable, but not necessary feature to support. > Either way, THE PREVIOUSLY SUBMITTED PATCH WAS **NOT SUITABLE**. I accept that it may not have been optimal, but I think this is just one perspective. > (And Cumulus were extremely slow in engaging on comments on that patch - > I'm sure it's been over a year since I first tried to have a dialogue > about that patch with them). > >> So this is where I think we're going to disagree. I just don't see >> folks operating their networks with max link cost in the normal case, so >> I'm not really too concerned about the old Quagga routers. I accept >> this is a matter of perspective, and unless an operator/user stands up >> and starts arguing this -- I suspect we're going to continue to >> disagree. > I agree with you. I don't think it's a major issue at all generally. > Others raised concerns that it could be though. So, even on mixed networks > that have topologies where this loop is *possible*, I suspect it's rare > it's ever an issue. However, /if/ it's an issue, I could agree it'd be an > annoying one ("Hmm, why are my switches melting?"). yes loops are bad. The possibility of changing a config on a major vendor router, e.g., cisco or juniper, and having the network melt due to quagga non-conformance (which is likely to be viewed as a bug by most) would be *really* bad for quagga- IMO... > >> As I said above, I think getting *a* fix in for this, and getting code >> base moving is more important than getting the default "right" -- again >> just one opinion. > That's great. But if it's not an issue, there's no issue in disregarding a > patch that lacks the config option, and then waiting for one that does > have it (which now exists). > > It's potentially also not an issue - given how long Quagga has had this > behaviour - to wait for H-bit. > >> As long as the H bit usage follows the latest WG draft -- no need to >> introduce something quagga specific here... > H-bit support would be fully conformant, in the sense it would be acted on > regardless of the 0xffff SPF compatibility setting. In the patch I sent. > >> this is the crux of disagreement - I think you're proposing going >> through a lot of work for a set of corner-case users that don't exists >> (those who run quagga and today use max cost in every day stable >> operations.) Maybe I'm wrong and my perspective is influenced by >> non-quagga usage. > Well, I've had people telling me how bad routing loops are, and won't > someone think of the routing loops! (humour), so forgive me if I went and > took those concerns seriously. > > It's frustrating to have to deal with ever shifting concerns. At a purely > logical level, if routing loops are an issue then the first Cumulus patch > was insufficient and more work was needed; if not such a huge issue, then > what is the issue in setting it aside and taking the time to see if both > current Quagga and "transit OK" behaviour could be accommodated together > (and the Quagga behaviour is actually useful - a standard is proposed to > allow that behaviour to be signalled)? > > The responses I've had do not make logical sense to me. Particularly > viewed in the context of how we've treated other interoperability/default > issues (interoperability with system configuration like link-default; or > with RFCs, like the RIP auth bug of ages ago, or this). > > Apparently the issue is serious enough that WE MUST APPLY A PATCH! So > urgent, we must apply one that /extends/ the issue that is so concerning > to further networks in the interim, but we don't have to look at patches > that try minimise that and make it configurable cause the issue isn't > serious. > > Baffling really. > >> I suspect it (stable usage of max cost) is rarely used so am really just >> arguing against all the extra work (and time) to get to same end state. > Max cost would be used for limited windows of time. The concern seemed to > be those windows can be long enough for routing loops to be nasty. > >> Again, IMO it would be better to get *something* in that allows either >> operation under config control while we/whoever wants continues this >> debate on the default behavior... > Agreed. > > ****There is only 1 patch that adds config options***!!!!! I think we're both repeating ourselves at this point - so let me up level: 1) how do we move forward on the max cost behavior 2) how do we get moving on the next release (and the clearing out http://patchwork.quagga.net/project/quagga/list/)? Lou > regards, _______________________________________________ Quagga-dev mailing list Quagga-dev@lists.quagga.net https://lists.quagga.net/mailman/listinfo/quagga-dev