On Fri, Sep 27, 2002 at 01:38:44PM -0500, John Hawley wrote:
> Did something change in the kernel between 2.4.17 and 18 concerning ICMP
> fragmentation?  I've been noticing (and getting complaints from local
> users) that some web sites are unaccessable.  

IIRC, ECN (Explicit Congestion Notification) was turns on by default.
This causes problems with some firewalls (that haven't been upgraded).
Jeff Garzik has a web page with details about this.  

To turn it off `echo 0 > /proc/sys/net/ipv4/tcp_ecn`

Nate