On Fri, Nov 22, 2019 at 12:32 PM Baldur Norddahl <baldur.nordd...@gmail.com> wrote: > > > > On Fri, Nov 22, 2019 at 1:21 AM Christopher Morrow <morrowc.li...@gmail.com> > wrote: >> >> On Fri, Nov 22, 2019 at 2:01 AM Saku Ytti <s...@ytti.fi> wrote: >> > >> > On Thu, 21 Nov 2019 at 19:44, Baldur Norddahl <baldur.nordd...@gmail.com> >> > wrote: >> > >> > > A BGP reset can cause routing trouble for as much as 15 minutes. Since >> > > you have two sessions that mitigates the problem somewhat. But >> > > nevertheless this will not be acceptable. >> > >> > As there are best path algorithms which consider route age, BGP reset >> > impact may be indefinite. >> >> fortunately we have a second actual provider... so this all isn't >> super impacting to us, just weird and unexpected on my part. >> > > No that is not helping. When the BGP session flaps your routes via that > provider are withdrawn. Everyone out there that were using those routes will > need to switch. But consider the following: > > ISP A has routes from both of your providers > ISP B has A as uplink > > BGP works so that ISP A is only announcing the route that he is actually > using to ISP B. ISP B therefore does not have both of your routes. When the > active route is withdrawn ISP B will momentary be without any route to your > network. It can take some time after the withdraw before ISP A announces that > he now is using the alternative route. This gets worse with longer chains. > Also some ISPs are using route flap limiting techniques that can prolong this > process. > > As I said, my experience is that you can expect as much as 15 minutes of > flaky internet after a BGP reset. This is with multiple transit providers.
Yup, I'm sensitive to flapping causing problems. This was why i started the thread, which really should have been: "Is there a well known bug people are working around? or is this a new problem I should chase with the provider? or 'nah, everyone does this, you just aren't normally paying attention'" > > I can not say too much about why you have BGP resets, but I can say that you > really want it fixed. It will affect your connectivity. > fortunately 3am local time is not prime-internet-use time :) phew! (not a great excuse though, of course) I'll be chasing up the provider to see what's up. thanks! -chris > Regards, > > Baldur >
