Juniper BGP Convergence Time

Thu May 17 15:19:44 UTC 2018

You shouldn't need to contact your ISP on the lowered BGP timers as BGP
should establish based on the lowest value.  That said, they may have a
value limit where anything lower than that, is set at your own risk.

You can look at running BFD over the BGP session as well.  Technically it
has nothing to do with convergence, but it can quickly detect a down issue
and drop BGP right away.

On Wed, May 16, 2018 at 9:22 AM, Adam Kajtar <akajtar at wadsworthcity.org>
wrote:

> I could use static routes but I noticed since I moved to full routes I have
> had a lot fewer customer complaints about latency(especially when it comes
> to Voice and VPN traffic).
>
> I wasn't using per-packet load balancing. I believe juniper default is per
> IP.
>
> My timers are as follows
>  Active Holdtime: 90
>  Keepalive Interval: 30
>
> Would I be correct in thinking I need to contact my ISP to lower these
> values?
>
> An interesting note is when I had both ISPs connected into a single MX104
> the failover was just a few seconds.
>
> Thanks again.
>
>
>
> On Tue, May 15, 2018 at 8:42 PM Ben Cannon <ben at 6by7.net> wrote:
>
> > Have you checked your timeouts ?
> >
> > -Ben
> >
> > > On May 15, 2018, at 4:09 PM, Kaiser, Erich <erich at gotfusion.net>
> wrote:
> > >
> > > Do you need full routes?  What about just a default route from BGP?
> > >
> > > Erich Kaiser
> > > The Fusion Network
> > > erich at gotfusion.net
> > > Office: 815-570-3101
> > >
> > >
> > >
> > >
> > >> On Tue, May 15, 2018 at 5:38 PM, Aaron Gould <aaron1 at gvtc.com> wrote:
> > >>
> > >> You sure it doesn't have something to do with 60 seconds * 3 = 180
> secs
> > of
> > >> BGP neighbor Time out before it believes neighbor is dead and remove
> > routes
> > >> to that neighbor?
> > >>
> > >> Aaron
> > >>
> > >>> On May 15, 2018, at 9:10 AM, Adam Kajtar <akajtar at wadsworthcity.org>
> > >> wrote:
> > >>>
> > >>> Hello:
> > >>>
> > >>> I'm running two Juniper MX104s. Each MX has 1 ISP connected running
> > >>> BGP(full routes). iBGP is running between the routers via a two port
> > 20G
> > >>> lag. When one of the ISPs fails, it can take upwards of 2 minutes for
> > >>> traffic to start flowing correctly. The router has the correct route
> in
> > >> the
> > >>> routing table, but it doesn't install it in the forwarding table for
> > the
> > >>> full two mins.
> > >>>
> > >>> I have a few questions if anyone could answer them.
> > >>>
> > >>>  - What would a usual convergence time be for this setup?
> > >>>  - Is there anything I could do speed this process up? (I tried
> > >> Multipath)
> > >>>  - Any tips and tricks would be much appreciated
> > >>>
> > >>> Thanks in Advance
> > >>> --
> > >>> Adam Kajtar
> > >>> Systems Administrator
> > >>> City of Wadsworth
> > >>> akajtar at wadsworthcity.org
> > >>> -----------------------------------------------------
> > >>> http://www.wadsworthcity.com
> > >>>
> > >>> Facebook <http://www.facebook.com/cityofwadsworth>* |* Twitter
> > >>> <https://twitter.com/CityOfWadsworth> *|* Instagram
> > >>> <https://www.instagram.com/cityofwadsworth/> *|* YouTube
> > >>> <https://www.youtube.com/channel/UCymlH-AZgvxTaHtgp3-AmDQ>
> > >>
> > >>
> >
>
>
> --
> Adam Kajtar
> Systems Administrator, Safety Services
> City of Wadsworth
> Office 330.335.2865
> Cell 330.485.6510
> akajtar at wadsworthcity.org
> -----------------------------------------------------
> http://www.wadsworthcity.com
>
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>