> Lately, I've been having an issue where my e-mail is timing
> out when I send an attachment. Whereas if I send just an
> e-mail I do not have any issues.
> I ran ethereal v0.10.13 to capture some packets and notice a
> great deal of retransmissions and checksum errors. I've run
> previous versions of ethereal and never had any of these. I
> read in the FAQ regarding checksum issues and I'm not sure
> this is generated because the packets are just handed over.
> I've exported the packet capture in a plain text file at
> http://www.mmtnetworks.com.au/email-attachmt.txt.
> Would appreciate any help on what the cause may be.
Note that the checksum error says the following:
"Header checksum: 0x0000 [incorrect, should be 0x34ee]"
I get that on my gigabit copper NIC (on send), and reading the faqs
about it, it could be the TCP Offload Engine computing the checksums
that ethereal cannot see.
Unfortunately my card here is a crappy onboard Broadcom and there's no
setting in the driver to tell it not to use the TOE, so I can't disable
it, which is annoying.
On my quality 3com/intel fibre cards, you can disable this in the driver
(although I've never needed to try it).
Chris