Hi Stuart, all please find my responses below, On Tue, 18 Sep 2018 at 11:14, Stuart Henderson <s...@spacehopper.org> wrote: > > On 2018-09-18, Claudio Jeker <cje...@diehard.n-r-g.com> wrote: > > > > I recomend using the default especially against ebgp peers. > > MikroTik in particular are known to be bad at keeping up with BGP timers. > Yes we have had some pain with this we are migrating off them (slowly but surely)
> > > > bgpd should be able to handle the minimal hold time with 30 or 60 > > peers just fine but I'm not so sure about any other system. Also flaping > > sessions because of too aggressive holdtime is counterproductive the > > session flap dampening will kick in and will keep session longer down than > > needed. Thanks for this insight it really helpful > > > > In the end, like with most tuning, you need to check for yourself with what > > you are comfortable with. > > This is mostly down to what your peers can handle (at a particular time), > and other people's real world experience will mostly not reflect that. > yes, Im more concerned about the L3 Switches that would be running BGP and the speed of their control plane... > You might think to check "bgpctl sh nei" over time and monitor how "Last > read" compares with "keepalive interval" to get a baseline, but if you do > then beware, that will mostly just show things under a normal situation. > If hold times expire because somebody's router is too busy on occasion, > flapping the session is just going to make it *even more* busy, adding > to the problem (which can be especially nasty at an IXP). > the read times vary between 1 and 3 seconds from my tests, > Are you seeing actual problems with peers that cause you to want to do > this? It was mainly an issue internally where we had alot of IGP sessions (full Table) with multihop bgp sessions running (which depend on OSPF), we had some problems with a couple of routers were oSPF would loose adjacency and I was trying to lower the impact of those on BGP. or improve convergence times if / when it happened.. I just need to migrate off those routers that are causing me pain > > - If so and it's IXP-wide, maybe talk to the IXP? If it happens during > maintenance and they aren't already following BCP214 (session culling), > perhaps they could do that. Thankfully it is not an IXP wide issue.. > > - If so and it's individual peers, maybe consider dropping them if > they're unreliable and not that important, or talking to them if they > are important? They are internal peers so they are important ... I will stick to the defaults based on what Stuart and Claudio Recommended Thanks I really appreciate your help, > > -- Kindest regards, Tom Smyth Mobile: +353 87 6193172 The information contained in this E-mail is intended only for the confidential use of the named recipient. If the reader of this message is not the intended recipient or the person responsible for delivering it to the recipient, you are hereby notified that you have received this communication in error and that any review, dissemination or copying of this communication is strictly prohibited. If you have received this in error, please notify the sender immediately by telephone at the number above and erase the message You are requested to carry out your own virus check before opening any attachment.
