will ISP peer with 2 local WAN routers?

Eugeniu Patrascu eugen at imacandi.net
Tue Aug 20 09:43:27 UTC 2013


A bit late to the discussion, but we use a stack of EX switches which
terminate L2 connections from the providers and two routers which have BGP
sessions with them.
Each switch has ports provisioned so that in case one switch fails, we just
simply move the ethernet cable to the working switch and everything is fine.

Eugeniu


On Sat, Aug 17, 2013 at 12:47 AM, Adam Greene <maillist at webjogger.net>wrote:

> Pete,
>
> Good point, thanks. Yes, in this case, there is some cause to believe that
> the switches will prove more reliable than the routers. They're older
> 7200VXR's and have had some lockups in the past, possibly due to PA card /
> IOS incompatibilities.
>
> But you're right, we are also considering accepting full or partial routes
> from both providers, one provider per router, and then doing iBGP between
> them to balance the load. We're thinking of deploying default routes and
> HSRP to stacked 3750's for round-robin load balancing on the LAN side.
>
> Thanks for the help!
>
> Adam
>
>
> -----Original Message-----
> From: Peter Kristolaitis [mailto:alter3d at alter3d.ca]
> Sent: Friday, August 16, 2013 5:30 PM
> To: nanog at nanog.org
> Subject: Re: will ISP peer with 2 local WAN routers?
>
> But the switches themselves are a single point of failure, so if a switch
> dies you still only have a single provider (assuming one switch per
> provider).  ;)
>
> All you're doing is moving the your single point of failure from the
> routers
> to the switches, with arguably very little increase in actual reliability
> (if any, depending on whether you think switches are less likely to fail
> than routers).
>
> - Pete
>
>
>
> On 08/16/2013 05:21 PM, Adam Greene wrote:
> > Thanks, Justin. Yes, we considered that option, too. But then if one
> > WAN router goes down, the customer will only have connectivity through
> > a single upstream provider. We'd prefer to maintain connectivity to
> > both even if a router fails. Switches in front of the routers is no
> problem.
> >
> > -----Original Message-----
> > From: Justin Vocke [mailto:justin.vocke at gmail.com]
> > Sent: Friday, August 16, 2013 4:47 PM
> > To: Adam Greene
> > Cc: <nanog at nanog.org>
> > Subject: Re: will ISP peer with 2 local WAN routers?
> >
> > The gotcha with that is then you need a switch in front of the
> > routers. I'd just setup a carrier on each router and run ibgp between.
> >
> > Sent from my iPhone
> >
> > On Aug 16, 2013, at 3:35 PM, "Adam Greene" <maillist at webjogger.net>
> wrote:
> >
> >> Hi guys,
> >>
> >>
> >>
> >> I have a customer who peers via eBGP with Lightpath aka Cablevision
> >> (AS
> >> 6128) and Level3 (AS 3356) and wants to do some dual-WAN router
> > redundancy.
> >>
> >>
> >> I have heard that carriers will sometimes agree to set up a /29 WAN
> >> subnet for a customer and peer with (2) customer routers.
> >>
> >>
> >>
> >> The customer is delaying on providing me with the proper circuit ID &
> >> contact information to be able to call Lightpath and Level3 directly
> >> and find out if they will do this, so I thought of asking this list.
> >>
> >>
> >>
> >> Is anyone aware if Lightpath and Level3 will agree to something like
> this?
> >>
> >>
> >> Thanks,
> >>
> >> Adam
> >>
> >>
> >>
> >>
> >>
> >
>
>
>
>
>


More information about the NANOG mailing list