Subject: Re: fragmentation by NetBSD routers vs. reassembly on other systems....
To: NetBSD Networking Technical Discussion List <tech-net@NetBSD.ORG>
From: None <firstname.lastname@example.org>
Date: 09/02/2000 14:41:26
>> router 1 was broken from DF bit manipulation. it behaved like this:
>> - if DF bit is raised on a packet, it worked fine. it transmits
>> icmp "too big" as necessary toward source, if the source node sends
>> - if DF bit is off, it behaved wrong. if the source node sends
>> 1500byte-packets, it drops the packet onto the floor. router 1
>> should have fragmented the packet on its own and relay it to router 2
>> (VLAN side), but it did not.
>My "router 1" is my 486/66 NetBSD-1.4V machine with a GIF tunnel, and it
>does appear to successfully send fragmented packets, and most remote
>systems do recieve those fragmented packets sucessfully and they
>apparently reassemble them without problems.
>Other than that though your observations do appear to match my own.
don't you have any other (not-administered-by-you) device in the middle?
when i read your original posting my impression was that you are
having problem with SMTP, to far-away peers.... anyway, you may want to
gather as much tcpdump traces as you can, and cross-check these to see
anyone is behaving strange.