Juniper BGP Convergence Time

Thu May 17 12:55:20 UTC 2018

Just be aware of the impact a default route can have on your infrastructure, such as uRPF no longer works as expected as everything has a valid route. 

----- 
Mike Hammett 
Intelligent Computing Solutions 
http://www.ics-il.com 

Midwest-IX 
http://www.midwest-ix.com 

----- Original Message -----

From: "Adam Kajtar" <akajtar at wadsworthcity.org> 
To: erich at gotfusion.net 
Cc: nanog at nanog.org 
Sent: Wednesday, May 16, 2018 9:32:27 AM 
Subject: Re: Juniper BGP Convergence Time 

Erich, 

Good Idea. I can't believe I didn't think of that earlier. Simple and 
effective. I will go ahead and request the defaults from my ISP and update 
the thread of the findings. 

Thanks! 

On Wed, May 16, 2018 at 10:03 AM Kaiser, Erich <erich at gotfusion.net> wrote: 

> A last resort route (default route) could still be good to take from your 
> ISP(s) even if you still do full routes, as the propagation is happening on 
> the internet side, you should at least have a path inbound through the 
> other provider. The default route at least would send the traffic out if 
> it does not see the route locally. Just an idea. 
> 
> 
> 
> On Wed, May 16, 2018 at 8:22 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 
> > 
> > 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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