RE: Faster 'Net growth rate raises fears about routers

From: Travis Pugh []
Sent: Tuesday, April 03, 2001 10:34 AM

I'm at a multi-POP network in Boston. We've had great luck selling
customers a Verizon circuit into one of our POPs and a
Worldcom circuit
into a different one. It costs more, but they don't have nearly the
exposure of a single circuit customer. However, if you're
not set up to
do this, the appropriate level of paranoia calls for circuits to two
different providers. Maybe if SPs really addressed availability
requirements of their customers, it wouldn't be such an issue.

The problem with this, if done, is that we back right into the other problem
of prefix filtering. If the customer has a /19 or /20, there is generally no
problem. But, if it is the usual case (/24) then only one of the upstreams
can aggragate the routes up. What is the other ISP to do? How would this be
made to work? BTW, this is exactly the reason we weren't fully multi-homed

Yes, greg described a way where both interfaces (end point) were NAT'd.
However, I have a concern with brittleness and tinker-factor there.

Apologies. We are a SP, and offer this service to customers. They get
redundancy, and we don't have to punch holes in our aggregates.


Cisco has a knob for conditional advertising. If this functionality were
standardised, documented and marketed more installation consultants could
make use of it. This would undoubtably help the aggregation cause as most of
the time fault conditions would not be active.