Well, I finally found the trick: /sbin/ip route change to <ipaddr/prefix> via <gateway> mtu lock 1500 This command will disable MTU path discovery and all packets on the route will be sent without DF bit set. The only question now is how to configure this to be permanent? > -----Original Message----- > From: Pavel Rozenboim [mailto:pavelr@xxxxxxxxxxx] > Sent: Sun, June 29, 2003 9:45 AM > To: shrike-list@xxxxxxxxxx > Subject: RE: How to prevent IP fragmentation > > > > > > -----Original Message----- > > From: Emmanuel Seyman [mailto:seyman@xxxxxxxxxx] > > Sent: Thu, June 26, 2003 10:02 PM > > To: shrike-list@xxxxxxxxxx > > Subject: Re: How to prevent IP fragmentation > > > > > > On Thu, Jun 26, 2003 at 10:39:48AM +0200, Pavel Rozenboim wrote: > > > > > > I have a shrike and psyche boxes, which reside in different > > subnets that are > > > connected through Win2k router. Whenever I send a long > > packets between them > > > I get a "Destination unreacheable" response saying > > "Fragmentation needed" > > > from a router. In ethernet sniffer I see that both boxes > set a don't > > > fragment flag in the IP header. Is there a way to prevent > > this behavior. > > > > Run the command "echo 1 > /proc/sys/net/ipv4/ip_always_defrag" . > > > > If you want to make it a permanant setting, put this in > > /etc/sysctl.conf > > and run the command "service network restart": > > > > # Enables automatic defragmentation > > net.ipv4.ip_always_defrag = 1 > > Emmanuel, > > There is no such file in /proc/sys/net/ipv4 directory. > > > -- > Shrike-list mailing list > Shrike-list@xxxxxxxxxx > https://www.redhat.com/mailman/listinfo/shrike-list >