Thoughts on BGP and Shared Hosting Environments

Had an interesting situation yesterday.

Received a new /20 allocation.
Split it into /19's and advertised it to two separate backbones via two
separate routers.

Users on the new /19's could get to about 75% of the available web hosts on
the internet.

I removed the /19's and advertised the entire /20 out of both servers,
problem resolved.

Any suggestions?

Also, what are the groups opinions on web hosting customers who want to
install custom ASP and COM components on a shared Windows 2000/IIS hosting
server? I'm having a debate with a sales dude over this issue.

My opinion is that it potentially destabilizes all of the virtual hosts on
that system. When I hear "Can you install just a couple of ASP or COM
components on my domain" my mind immediately goes to putting this customer
in their own dedicated colo server. I don't think its right to jeopardize
several hundred virtual domains because one $19.99/month customer wants to
load up a special .dll. But that's just my rant, market conditions can
dictate otherwise.

Christopher J. Wolff, VP, CIO
Broadband Laboratories, Inc.
phone:520.622.4338 x234

I hope you meant 2 /21's...


Received a new /20 allocation.
Split it into /19's

send code!


Your problem may be that, when you split a /20, you get two /21s, not two
/19s. Also, this is probably not the right forum for questions about NT web
hosting - you may get better, or at least more constructive, information,
elsewhere on that topic.

- Daniel Golding

Track which components are being asked for and consider supporting for the more popular ones. We did this when I was at Virtualscape and found it to be an easy way to differentiate your service and make customers happy.

It would be interesting to know what is happening to traffic in the broken
2x/21 setup. Did the various looking glasses see it correctly? Is it out
of traditional class a space, or that new block just assigned to apnic?

Brian "Sonic" Whalen
Success = Preparation + Opportunity

I'm guessing that the problem wasn't users getting to the sites. It was the
data getting back...

Normally, when folks advertise space less then RIR guidelines, the also
advertise the larger aggregate, to ensure that this sort of thing doesn't
happen due to filtering. Try advertising the /21s out each link, then the
aggregate out both links. As well. You should have most traffic going to the
more specifics, with some traffic, from route filteded networks using the
aggregates. The latter traffic will route via the more specifics, when it
reaches a network that knows them. In the worst case, this is slightly
suboptimal routing for those from route-filtering networks.

- Daniel Golding

Hmm, according to my error logs, the most requested components at
my site are /winnt/system32/cmd.exe and /htdocs/scripts/root.exe.

Couldn't resist. :wink:

Good point about which components to consider, though-- may be able
to make many folks happy with minimal disturbance.

Some sites run an "experimental, at your own risk" server with
some extras, for their most vocal customers. Putting the double
handful of whingers there can often be simpler than losing their
business, though admittedly it doesn't scale for very large


Rachel Luxemburg wrote: