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Re: Re: Re: trouble about IP Fragmentation by using the Linux Virtual Se

To: frederic.buche@xxxxxxxxxx
Subject: Re: Re: Re: trouble about IP Fragmentation by using the Linux Virtual Server
Cc: lvs-users@xxxxxxxxxxxxxxxxxxxxxx
From: Julian Anastasov <ja@xxxxxx>
Date: Mon, 16 Sep 2002 16:32:29 +0300 (EEST)
        Hello,

On Mon, 16 Sep 2002 frederic.buche@xxxxxxxxxx wrote:

> Our trouble has now disappeer with the patch you gave me.
> Is it only a temporary patch or can I include it definitely on my system ?

        I have attached another patch, that changes other
cases, before we decide what will be the best looking fix. But
you can live even with the first patch (DR only).

        Hm, bad csums?:

> 10:02:14.545925 195.101.125.28.18232 > 195.6.241.14.smtp: . [bad tcp cksum
> 8291!] 71612:71612(0) ack 466327435 win 0 (DF) (ttl 59, id 21494, len 40)
> 10:02:14.545946 195.101.125.28.18232 > 195.6.241.14.smtp: . [bad tcp cksum
> 8291!] 0:0(0) ack 1 win 0 (DF) (ttl 59, id 21494, len 40)

        Yes, it is working but may be the tcpdump snap length is too
short to correctly calculate the csum for the long packets, the
csum state is not shown (tcpdump -s 2000):

> 10:02:16.119955 195.101.125.28.18232 > 195.6.241.14.smtp: . 88:1516(1428)
> ack 295 win 8466 (frag 57119:1448@0+) [tos 0x10]  (ttl 124, len 1468)
> 10:02:16.120019 195.101.125.28.18232 > 195.6.241.14.smtp: . 88:1548(1460)
> ack 295 win 8466 [tos 0x10]  (ttl 124, id 57119, len 1500)
> 10:02:16.120464 195.101.125.28.18232 > 195.6.241.14.smtp: P 1548:1893(345)
> ack 295 win 8466 (DF) [tos 0x10]  (ttl 124, id 57375, len 385)
> 10:02:16.120485 195.101.125.28.18232 > 195.6.241.14.smtp: P 1548:1893(345)
> ack 295 win 8466 (DF) [tos 0x10]  (ttl 124, id 57375, len 385)

        Thanks, we should provide fix for the next release.

> Frédéric BUCHE
> maito : frederic.buche@xxxxxxxxxx

Regards

--
Julian Anastasov <ja@xxxxxx>

Attachment: csum2.diff
Description: csum v2

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