Hello all,
I have been having network problems since I installed Ethereal and WinPcap
about three weeks ago. Strangely, my network connection speed drops
significantly when Ethereal is not capturing packets. When I start
capturing, everything speeds up significantly, and when I stop, it slows
down again. Also, the problem has only affected my OEM 802.11 wireless LAN
connection, and not my OEM Ethernet connection (laptop PC). Here are some
details relating to my setup:
I am connected through ADSL, behind a firewall/gateway
I am running Windows XP on a fairly new laptop
My laptop has two network adapters: An Intel Ethernet LAN card and a Toshiba
802.11 wireless card
The problem does not affect other computers on my subnet, my wired LAN
connection, or large data transfers from other PCs in my subnet while using
the affected wireless 802.11 connection. In other words, it only affects my
wireless connection while connecting to hosts outside my subnet while I am
not capturing packets with Ethereal.
Memory and CPU resource utilization do not appear to be an issue
Excessive network traffic is quite certainly not an issue
I have done several thorough checks for any unwanted software using
Hijackthis, Spybot, etc
I have checked for viruses using AVG
Zonealarm is installed but disabled
netstat reports negligible or no packet loss at all of the Ethernet/IP/TCP
layers, even when the problem is occurring
I don't know enough about Ethereal to determine whether the problem is
Ethereal or WinPcap. From the information that I have found, the WinPcap
driver that Ethereal loads when capturing can be manually started and
stopped from the prompt by net start npf and net stop npf. Performing
either of these operations does not seem to make any difference. I have
searched the FAQs and lists to the best of my ability, but typically, people
seem to have network slowness problems when capturing with Ethereal, not the
opposite, as I have. Thanks in advance!
Peter
