From: P729 (p729@xxxxxxx)
Date: Fri Jun 21 2002 - 16:33:29 GMT-3
You can't really "prevent" it. While you can control how traffic leaves your
network, you can only influence how traffic comes to your network to a
limited degree, as in sending BGP MEDs (which are often ignored), prepending
your AS-path or perhaps sending well-known communities.
Depending on your arrangement with your ISP, you'll pretty much have to talk
them into traffic engineering the path(s) taken by traffic destined for your
network from the Internet-at-large. It's more feasible if all of your
traffic comes via one ISP, but it becomes more difficult (perhaps totally
impractical) when two or more are involved and you aren't taking full
routes.
Regards,
Mas Kato
https://ecardfile.com/id/mkato
----- Original Message -----
From: "Carlos G Mendioroz" <tron@huapi.ba.ar>
To: "Groupstudy ccielab list" <ccielab@groupstudy.com>
Sent: Friday, June 21, 2002 11:18 AM
Subject: Re: HSRP: the other side ?
> It seems I'm not making an interesting thing out of this :-(
>
> Say you have 2 routers like before, but one has a 100Mbit interface
> and is the preferred access, and the other is an old 4000 with only
> 10Mbit interface, but you do HSRP between them not to have a
> single point of failure on the router. Obviously you don't want
> your traffic to come via the 10Mbit half duplex interface to your lan.
>
> How would you prevent it ?
>
> Carlos G Mendioroz wrote:
> >
> > I'm still looking for a way to solve what I think is a problem ;-)
> > Namely, you have a network and a couple of routers doing HSRP
> > for providing redundant exit path to the rest of the world.
> >
> > As I see it, this has two sides.
> >
> > 1) The inside:
> > HSRP solves the redundancy by using a polling mech (HSRP) to
> > identify which router out of a group is responsible for the
> > group MAC and IP. Every host on the net uses this MAC/IP to
> > go out. It works and actually can deal with many problems
> > (with track you can even react to some external problems).
> >
> > 2) The outside:
> > The rest of the world need to know how to reach your network.
> > And here, AFAIK HSRP has no hooks to make this easy.
> >
> > E.g.
> >
> > N -- R1 -- wan link to ISP
> > E
> > T -- R2 -- backup wan link to ISP
> >
> > When R2 turns active, how does it signal ISP that now traffic to your
> > net
> > should be forwarded to it (instead of to R1) ?
> >
> > It's easy if R1's net interface went down, but it might not be the
> > case...
> >
> > Comments ?
> > I have some weird ideas, but would like to know if there is an orthodox
> > way out.
> >
> > --
> > Carlos G Mendioroz <tron@huapi.ba.ar> LW7 EQI Argentina
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