RE: BGP Load Balancing

That's not why...

The inbound traffic has issues (again I cite Cogent from using them every day
for 10 years) because they have network configuration issues -and other
Tier1's steer traffic away from them... so while you think "you are
multi-homed 2 two tier1's) there is Level3 and then there is everyone else -
then WAY down on the list is Cogent... I have seen frequently stuff like NY to
NJ traceroutes going through Chicago or San Jose if Cogent is involved..
imagine the inbound???? YIKES!!

My AS is multi-homed with level3 and hurricane - but Level 3 is so good (I'm
on the same edge router as salesforce.com :) I don't need load balancing)

Now, regarding outbound - would you want 50% of your traffic to use a crappy
carrier, if you have a 1 good/fast carrier?

I never do load balancing for that reason- we just buy big enough circuits so
that the primary is much larger than the needs of the network - if youre not
getting those prices - shop around... its affordable now

From: Nicky [mailto:ccienovice_at_gmail.com]
Sent: Tuesday, August 28, 2012 11:18 AM
To: Joseph L. Brunner
Cc: ccielab_at_groupstudy.com
Subject: Re: BGP Load Balancing

Joseph,

In "Provider+default routes" case Tier-I ISP's also cannot provide much of
help.The upstream peers can manipulate the traffic.

The outbound traffic will load balance(not perfectly but still...) but inbound
will always have an issue.
On Tue, Aug 28, 2012 at 8:36 PM, Joseph L. Brunner
<joe_at_affirmedsystems.com<mailto:joe_at_affirmedsystems.com>> wrote:
No true.. it's much more likely you will see inbound traffic load balanced as
your carriers run default-less - as do their upstream peers...

Your unique /24 (or whatever length) netblocks will be sent through the
internet from both of your sources, and random traffic will come in via
either, assuming no other attributes are changed between providers...

Now, outbound is much harder in that scenario... with cef enabled (and it has
to be for many reasons) you would need some per-packet load balancing and that
may not be what you want if one carrier is much better connected or just plain
faster than another...

I would recommend if you truly want to load balance, forget about default-only
and take "Provider + default routes" this way you are assured to send traffic
to your provider to get to mutual customers... this works best when you ISP's
are 2 great ones, like Level3 and ATT. It works not so great when you use
Level3 and Cogent let's say - as Cogent has all sorts of bad routing policies
and you will not have much luck.

Thanks!

-----Original Message-----
From: nobody_at_groupstudy.com<mailto:nobody_at_groupstudy.com>
[mailto:nobody_at_groupstudy.com<mailto:nobody_at_groupstudy.com>] On Behalf Of
Nicky
Sent: Tuesday, August 28, 2012 11:00 AM
To: ccielab_at_groupstudy.com<mailto:ccielab_at_groupstudy.com>
Subject: BGP Load Balancing

Hi All,

If there are two ISP terminating on two different routers and only default
route is accepted from ISP then can I load balance the traffic?

AFAIK the outgoing traffic will be load balanced but not possible for incoming
traffic.

Regards,
Nick

Blogs and organic groups at http://www.ccie.net
Received on Tue Aug 28 2012 - 15:22:20 ART