IP header checksum missing with Realtek 8168,
jumbo frames and offloading.
pyunyh at gmail.com
Mon Mar 3 00:43:48 UTC 2008
On Sun, Mar 02, 2008 at 11:44:03PM +0100, Arnaud Houdelette wrote:
> I encountered connectivity issues with an integrated Realtek 8168 on my
> MSI motherboard after enabling jumbo frames on my other box.
> Investigating the issue, I found that the packets with an ethernet frame
> of length > 2048 get an IP header of 0x0000.
> ping -s 3000 192.168.0.11 ==> fail (ethereal on the other box show the
> 0x0000 checksum on IP header)
> ping -s 2008 192.168.0.11 ==> fail
> ping -s 2006 192.168.0.11 ==> succeed
> re0: <RealTek 8168/8111B PCIe Gigabit Ethernet> port 0xd800-0xd8ff mem
> 0xfeaff000-0xfeafffff irq 19 at device 0.0 on pci2
> re0: Using 2 MSI messages
> miibus0: <MII bus> on re0
> rgephy0: <RTL8169S/8110S/8211B media interface> PHY 1 on miibus0
> rgephy0: 10baseT, 10baseT-FDX, 100baseTX, 100baseTX-FDX, 1000baseT,
> 1000baseT-FDX, auto
> The interface re0 is configured with :
> ifconfig inet 192.168.0.1/24 media auto mtu 7422 polling
> ifconfig re0 -txcsum solves the issue.
> I tried to reproduce the issue with a Realtek 8169 (using re(4) too). I
> couln't : checksum offloading works ok on this card.
> Is this a known issue (or maybe a bug in the 8168) ?
There had been several re(4) instability issues on PCIe based
controllers. Would you try the following patch and let me know the
If you use 7.0-RELEASE use the following one.
> I can provide some network capture if needed. In the meantime I swapped
> the two cards as I don't need jumbo on one of them.
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