---------- sean@donelan.com wrote: ----------
The hard part is I now always take over networks that have been in
operation a long time and enabling these policies can be very painful
after the fact. Establishing them when the network is new is a
different story.
Whatever you decide, whether you know what the policies are or not, there
are always have a set of default network policies.
The question is do you explain to you customers just as carefully what
your default policy doesn't do, as well as what it does. Do you take
just as much time to carefully explain the risks and what may break to
your customers of allowing that traffic as you would of not allowing that
traffic.
It seems to be very painful whatever decision is made.
The default policy is we allow eveything. It takes no explaining.
If you don't bother to explain to the same customers who you believe couldn't figure out how to change the default settings, what the risks and how to protect their computers on the Internet, is it any wonder that normal user's have such a difficult time being safe on the Internet?
I understand the port 25 issue and am reconsidering it for dynamic addresses on outbound traffic, but at least one person on NANOG showed me a use of that. Like network engineers at many other companies, I'm spread so thin that it's hard to find the time to do work like this and I keep putting it on the back burner. VZ had it completely open and I have followed that as we seperated this network from their network, as
I can't take on the extra work of fixing brokenness that would result from applying the filter.
Like I said, there is always a default policy whether you know what
that policy is or not. You probably end up spending the resources on
the front-end or on the back-end.
Implementing source address verification can take years, but if you
never start, you will never finish.
Implementing sanity checks for IP headers can take years, but if you
never start, you will never finish.
Implementing unsolicited/unwanted traffic controls can take years, but
if you never start, you will never finish.
Do you think caller-id/call-blocking/harrassing-call-trace were easy, or
rather they took years of hard work. Although the technology may change,
people seem to stay the same. And people seem to be adept at doing the
same stuff with new technology to other people.