Cat 6k Private VLANs - was RE: SUMMARY: bw usage?

[Chance Whaley]

split-horizon states that you never should send information about a route
back in the direction from which it came. Typically, this is only applicable
to DV protocols and the like, but has meaning elsewhere. People have long
ignored the rules of split horizon for routing, ie. Frame Relay networks.
With the right configuration it really isnt an issue.

But now for the hosting environment its even less meaningfull. In the
private VLAN concept, communites of interest (for lack of a better term) are
manually created, that allow a given port to only speak (L2) with the router
port, and any other ports in its community. For the simple hosting
environment its perfect. Everyone is assigned out of the same addressing
block, regardless of the order in which the cages/servers were turned up.

This is probably not the greatest solution for colo providers hosting cages
and interconnects. But for a simple webfarm and hosting operations its very
workable.

My $0.02. From someone who as implemented them, and likes them very much.

.chance

-----Original Message-----
From: owner-nanog@merit.edu [mailto:owner-nanog@merit.edu]On Behalf Of
Alex Rubenstein
Sent: Friday, July 28, 2000 11:22 AM
To: Neil J. McRae
Cc: (David M. Ramsey); nanog@merit.edu
Subject: Re: SUMMARY: bw usage?




> You might want to look at cricket and RRDTool for a much more
> scalable solution. [http://cricket.soundforge.net/].
>
> >
> >    - Cisco 6500 switches apparently support "Private VLANS", which
> >      don't burn up IP addresses.  Sounds cool, wish I had a 6500 ;-)
>
> I'd be interested in finding out more about this as we are currently
> using CAT 6500 switches and burning up IP addresses can you tell
> me more about this?


If I'm not mistaken, Private VLANs causes a big time split-horizon issue..