Re: PMTU issues due to TOS field manipulation (for DSCP)
From: Andi Kleen <hidden>
Date: 2003-12-10 19:34:33
From: Andi Kleen <hidden>
Date: 2003-12-10 19:34:33
On Wed, 10 Dec 2003 10:23:15 -0800 (PST) "Kevin W. Rudd" [off-list ref] wrote:
Thoughts? Comments?
I don't think the network users will be very happy if you require changing all end hosts this way. How about the following hack? For DF=1 packets the ipid field is useless. When you rewrite the TOS to DSCP save the old TOS in the ipid field. When you see an ICMP fragment required message with the right DSCP on the router restore the old TOS from the ipid field. One drawback is that there are a few VJ header compression servers that require changing ipid. But you can still handle these by not overwriting all bits of ipid so that it still changes (keep a few changing bits) -Andi