Telco's write best practices for packet switching networks

Thu Mar 7 22:15:06 UTC 2002

On Thursday, March 7, 2002, at 04:37 , Sean Donelan wrote:

> My comment was originally prompted by the meeting minutes which
> reported on the survey data showing that 100% of carriers are 
> implementing
> firewalls in their gateways.  The 100% is what caught my eye.  As the
> topic comes up in various places, large ISPs repeatedly say they are
> unable to implement filters or packet screening on their high-speed
> links such as at peering points.

How recently are ISPs repeatedly saying this? Packet filtering on 
high-speed optical interfaces has been possible for some time, depending 
on your router vendor, for some value of "packet filtering".

I could understand it if the issue of how to manage packet filter 
definitions on routers as the network changes was a problem. But if I 
would be slightly surprised if there was still a universal voice saying 
"we absolutely cannot filter packets at the edge, because the vendors 
won't let us".

To meet the requirements of what I understood the original quoted 
fragment to be saying, it's perhaps not necessary to packet filter at 
the edge, anyway. You can apply a firewall to just the loopback 
interface of a junos box and arguably consider your control element 
firewalled.

Joe