Re: Packet corruption in re0

From: Pyun YongHyeon <pyunyh_at_gmail.com>
Date: Fri, 22 Feb 2008 19:20:26 +0900
On Fri, Feb 22, 2008 at 06:47:42PM +0900, To Ian FREISLICH wrote:

[...]
 >  > It seems like it's corrupting large packets on transmit when vlanhwtag
 >  > is enabled.  From the tcpdump output it looks like a padding or
 >  > packet length issue.
 >  > 
 >  > Here's what tcpdump on the re(4) device thinks it's transmitting:
 >  > 
 >  > 00:08:a1:3c:32:9c > 00:90:fb:0c:89:7d, ethertype 802.1Q (0x8100), length 1510: vlan 1000, p 0, ethertype IPv4, 196.22.138.92 > 196.22.138.89: OSPFv2, Database Description, length: 1472
 >  > 
 >  > Here's what was actually recieved by the em(4) device on the
 >  > neighbour.  Note the absense of the 801.1Q header:
 >  > 
 > 
 > I see, I'll check it.
 > 
 >  > 00:08:a1:3c:32:9c > 00:90:fb:0c:89:7d, ethertype IPv4 (0x0800), length 1506: 196.22.138.92 > 196.22.138.89: OSPFv2, Database Description, length: 1472
 >  > 
 >  > When vlanhwtagging is disabled, the re(4) device transmits:
 >  > 
 >  > 00:90:fb:0c:89:7d > 00:08:a1:3c:32:9c, ethertype 802.1Q (0x8100), length 1510: vlan 1000, p 0, ethertype IPv4, 196.22.138.89 > 196.22.138.92: OSPFv2, Database Description, length: 1472
 >  > 
 >  > and the em(4) device recieves:
 >  > 
 >  > 00:08:a1:3c:32:9c > 00:90:fb:0c:89:7d, ethertype 802.1Q (0x8100), length 1510: vlan 1000, p 0, ethertype IPv4, 196.22.138.92 > 196.22.138.89: OSPFv2, Database Description, length: 1472
 >  > 
 >  > Let me know if you need more detailed tcpdump output than I've provided.
 >  > 

Apply attached patch and let me know how it goes.
It just disables checksum offload for vlan interface.

-- 
Regards,
Pyun YongHyeon

Received on Fri Feb 22 2008 - 09:20:35 UTC

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