NAT and MTU

[Will Saxon]

> -----Original Message-----
> From: Brent Wiese [mailto:brently at bjwcs.com]
> Sent: Tuesday, July 08, 2003 8:45 PM
> To: freebsd-questions at freebsd.org
> Subject: NAT and MTU
> 
> 
> I have a machine that is being double-NAT'd.
> 
> Would it make sense to set the MTU lower to account for the 
> NAT overhead?
> 
> It makes sense to me as I know MTU, but I like to check in 
> case my thinking
> isn't right. :)


Why would it matter? Does NAT increase the overall datagram size? I thought it just changed addresses and stored connection information in a table somewhere. If this is the case, just having NAT, even 2x, isn't going to make it any more likely that your traffic will fragment.

-Will