Sequence of IP fragment packets on the wire

["Henning P. Schmiedehausen" <hps@intermeta.de>]

Hi,

as far as I can see, Linux sends out fragmented IP packets
"butt-first":

11:34:53.927146 alice > bob: (frag 44605:343@1480)
11:34:53.927189 alice.4831 > bob.udpdemo:  udp 1815 (frag 44605:1480@0+)

(where the first packet is actually the fragmented 2nd part of the
second packet).

This confuses at least one firewall appliance. As I understand it,
this is done for efficency reasons. Still, is there any way to
suppress this and get the packets sent out in "head first" sequence? I
know that routers might resort the fragments again but in my case I
have an "alice -- firewall -- bob" topology which at the moment drops
the fragment on the floor...

Is there a way to configure this? Maybe even connection specific? 

I tested 2.2.19 and 2.4.18 with 100 MBit Ethernet (3Com and eepro100).
Both show the same behaviour.

	Regards
		Henning



-- 
Dipl.-Inf. (Univ.) Henning P. Schmiedehausen       -- Geschaeftsfuehrer
INTERMETA - Gesellschaft fuer Mehrwertdienste mbH     hps@intermeta.de

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