[124880] in North American Network Operators' Group
RE: Best Practice: 2routers, 2isp, 1AS
daemon@ATHENA.MIT.EDU (Dylan Ebner)
Wed Apr 7 10:07:11 2010
From: Dylan Ebner <dylan.ebner@crlmed.com>
To: Beavis <pfunix@gmail.com>, "nanog@nanog.org" <nanog@nanog.org>
Date: Wed, 7 Apr 2010 14:06:25 +0000
In-Reply-To: <h2ne02ea4ef1004062242gdeddcbd5jcd7108aa4e16ea3f@mail.gmail.com>
Errors-To: nanog-bounces+nanog.discuss=bloom-picayune.mit.edu@nanog.org
You can still use vrrp in the inside. We have a similar configuration to wh=
at you have defined. Two routers, 4 ISPs, BGP annoucing 2 /24's. We get par=
tial routes and prepend on 3 of the isps to only use our primary. Our prima=
ry is delivered via fiber and the backup isps are delivered via copper ethe=
rnet. We use interface tracking with reachability to determine if we are ha=
ving a problem with one of our downstreams. This way, if we still have a li=
nk light, but no traffic flow we can detect and adjust accordingly.
Dylan=20
-----Original Message-----
From: Beavis [mailto:pfunix@gmail.com]=20
Sent: Wednesday, April 07, 2010 12:42 AM
To: nanog@nanog.org
Subject: Re: Best Practice: 2routers, 2isp, 1AS
thanks for the reply brian. :)
sorry for a bit lack on the info, I was thinking of using VRRP. but my
2 links are running on different interface-types isp1 runs via
ethernet while the other is on an ATM interface. I only have 1 router
that has an ATM interface. setting it to VRRP would cause me problems
if it was a physical failure. I have a small /24 to advertise on my
AS. I'll go and check on the "Performance Based Routing" you
recommend.
thanks,
-b
On Tue, Apr 6, 2010 at 11:25 PM, Brian Feeny <bfeeny@mac.com> wrote:
>
> There are alot more questions that need to be asked. =A0Like how much add=
ress space do you have to announce? What routes are you getting from each I=
SP?
>
> Assuming you are an end user, and knowing the very limited information I =
know at this point, I would make sure that these two routers LAN interfaces=
are in some sort of transit vlan/subnet with my downstream router, which w=
ould also be participating in iBGP. =A0Alternately you could have that rout=
er do VRRP/HSRP with your two border routers, but I prefer iBGP.
>
> I would then setup both routers using OER (Optimized Edge Routing, i thin=
k now known as Performance Based Routing), to handle outbound. =A0You could=
just announce your /24 out each provider (assuming that's what you had) to=
handle inbound, or if you have larger than that you could announce the agg=
regate out both and more specifics out each to do some type of balancing.
>
> Its hard to say there is a best practice here, as there are so many scena=
rios. =A0I will say that I like OeR/PfR for edge customers who are dual hom=
ed. =A0BGP is very arbitrary, and its nice to have some real metrics that m=
ean something to play with :)
>
> Brian
>
>
> On Apr 7, 2010, at 1:14 AM, Beavis wrote:
>
>> Greetings!
>>
>> =A0 Want to ask out anybody on the list about a "best practice" of the
>> setup below:
>>
>> - 2 ISP's (A & B)
>> - 2 Routers (A & B)
>>
>> I want Router-A for ISP-A, Router-B for ISP-B and have Router-A &
>> Router-B talk and be able to pass routes on each side in an event of a
>> physical failure on one of the Routers.
>>
>> I was planning at first to setup a multi-home BGP, but I want to have
>> physical redundancy as well.
>>
>> ASCII-diag
>>
>> =3D--[RouterA]--isp1(bgp)
>> L =A0 =A0|
>> A =A0 iBGP
>> N =A0 =A0|
>> =3D--[RouterB]--isp2(bgp)
>>
>> Any recommendation would awesomely appreciated.
>>
>> -B
>>
>>
>> --
>> () =A0ascii ribbon campaign - against html e-mail
>> /\ =A0www.asciiribbon.org =A0 - against proprietary attachments
>>
>
>
--=20
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