Re: Traceroute Mal-formed packets

From: Casey Carter (ccarter@cs.uiuc.edu)
Date: Thu Mar 06 2003 - 09:39:06 EST


John McLaren wrote:

>I stand corrected.. i should have said "udp length" rather than header length.
>I was under the impression that this had to be multiples of long words also.
>
>
You can even send a 0 byte UDP packet if you want, so any length >= 8
(the header size) is valid.

>Nonetheless... what is the need for any data in this packet? Traceroute
>uses incrementing to assure that the return packets can be effectively
>ID'd, right?
>
>
traceroute is a testing tool. Since you might want to determine where
packets to host X of size greater than Y bytes are being dropped, adding
data bytes is useful.

>If nothing else, this anomoly might be useful in identifying certain router
>types that consider this to be a mal-formed packet.
>
>
I think it's very likely that Cisco can build RFC791-compliant routers.
 The most likely source of problems here is the NAT setup.

>JMcLaren
>
>-
>To unsubscribe from this list: send the line "unsubscribe linux-net" in
>the body of a message to majordomo@vger.kernel.org
>More majordomo info at http://vger.kernel.org/majordomo-info.html
>
>

-- 
Casey Carter
Casey@Carter.net
ccarter@uiuc.edu
AIM: cartec69

- To unsubscribe from this list: send the line "unsubscribe linux-net" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html



This archive was generated by hypermail 2b29 : Fri Mar 07 2003 - 22:00:01 EST