the alleged evils of NAT, was Rate of growth on IPv6 not fast enough?

Jon Lewis jlewis at
Tue Apr 27 13:37:08 CDT 2010

On Tue, 27 Apr 2010 Valdis.Kletnieks at wrote:

> The difference is that if a protocol wants to be end-to-end, I can fix a
> firewall to not break it.  You don't have that option with a NAT.

Maybe we want end-to-end to break.

Firewalls can trivially be misconfigured such that they're little more 
than routers, fully exposing all the hosts behind them to everything bad 
the internet has to offer (hackers, malware looking to spread itself, 

At least with NAT, if someone really screws up the config, the "inside" 
stuff is all typically on non-publicly-routed IPs, so the worst likely to 
happen is they lose internet, but at least the internet can't directly 
reach them.

This has to be one of the bigger reasons people actually like using NAT.

  Jon Lewis                   |  I route
  Senior Network Engineer     |  therefore you are
  Atlantic Net                |
_________ for PGP public key_________

More information about the NANOG mailing list