Date: Fri, 16 Dec 2011 15:01:28 +0700 From: Eugene Grosbein <egrosbein@rdtc.ru> To: Andrea Venturoli <ml@netfence.it> Cc: freebsd-net@freebsd.org Subject: Re: Intel 82550 Pro/100 Ethernet and TSO troubles Message-ID: <4EEAFAD8.3010700@rdtc.ru> In-Reply-To: <4EE8FA10.8090502@netfence.it> References: <4EE8FA10.8090502@netfence.it>
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15.12.2011 02:33, Andrea Venturoli пишет:
> Hello.
>
> I recently installed 8.2 with the following card:
>
> > dmesg
> > ...
>> fxp0: <Intel 82550 Pro/100 Ethernet> port 0xdc00-0xdc3f mem 0xfebfb000-0xfebfbfff,0xfebc0000-0xfebdffff irq 20 at device 5.0 on pci4
> > ...
> > pciconv -lv
> > ...
>> fxp0@pci0:4:5:0: class=0x020000 card=0x00408086 chip=0x12298086 rev=0x0c hdr=0x00
>> vendor = 'Intel Corporation'
>> device = '82550/1/7/8/9 EtherExpress PRO/100(B) Ethernet Adapter'
>> class = network
>> subclass = ethernet
> > ...
>
> I had weird problems, especially due to ICMP/fragmentation/MTU/... issues.
> After hours spent in debugging, I noticed tcpdump showing ICMP packets
> with wrong checksums and that TSO4 was enabled.
> "ifconfig fxp0 -tso" seemed to solve everything.
>
>
> Don't know if it's a bug in the card, in the driver or what...
> Maybe it shouldn't be enabled by default?
Do you use NAT? man ipfw clearly states:
ipfw nat is not compatible with
the TCP segmentation offloading (TSO). Thus, to reliably nat your net-
work traffic, please disable TSO on your NICs using ifconfig(8)
Eugene Grosbein
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