Martin, The answer is (of course).... it depends. Here's what I've found from my testing.
1) Getting more than 40Mbit/s over any medium with NT/Win2K/XP with negligible packet loss is impossible. I'm not sure what the limitation is but it can't be libpcap as Windump is better than tethereal at this . Here's an example tracing the same UDP stream with WinDump and tethereal. d:\>WinDump -n -s 0 -i \Device\NPF_{C0BD2FFE-AB2B-4F7E-B9A7-25B6B232EA29} -B 10000 -w test.cap WinDump: listening on \Device\NPF_{C0BD2FFE-AB2B-4F7E-B9A7-25B6B232EA29} 1435240 packets received by filter 0 packets dropped by kernel d:\>tethereal -i \Device\NPF_{C0BD2FFE-AB2B-4F7E-B9A7-25B6B232EA29} -n -q -w test.cap Capturing on \Device\NPF_{C0BD2FFE-AB2B-4F7E-B9A7-25B6B232EA29} 416784 packets dropped 159952 packets captured 2) I have captured more than 2.4 Gbit/s over the loopback address on Linux. I needed to write to a RAMdisk to achieve this but it worked fine until the 2GB RAM disk filled up. [Then things went very bad :-)] 3) I have captured at 250Mbit/s for 3 minutes over Gbit, but this was limited by the CPU of the capturing box which was also running the application generating the traffic. Hence I believe (but have not tested) that ethereal will, on Linux, with the right CPU and fast enough disk, capture at wire speed 1Gbit/s. YMMV on Windows Alistair > -----Original Message----- > From: Martin Kowalewski [mailto:[EMAIL PROTECTED] > Sent: 10 July 2003 16:23 > To: [EMAIL PROTECTED] > Subject: [Ethereal-users] Throughput with Gigabit Ethernet > > > Has Anyone tested capturing packets at speeds greater than > 100MB, specifically Gigabit Ethernet? If so how close to > line rate packet capture can ethereal get to? > > Thanks, > > Martin > > _______________________________________________ > Ethereal-users mailing list > [EMAIL PROTECTED] > http://www.ethereal.com/mailman/listinfo/ether> eal-users > ----------------------------------------------------------------------- Registered Office: Marks & Spencer p.l.c Michael House, Baker Street, London, W1U 8EP Registered No. 214436 in England and Wales. Telephone (020) 7935 4422 Facsimile (020) 7487 2670 www.marksandspencer.com Please note that electronic mail may be monitored. This e-mail is confidential. If you received it by mistake, please let us know and then delete it from your system; you should not copy, disclose, or distribute its contents to anyone nor act in reliance on this e-mail, as this is prohibited and may be unlawful. The registered office of Marks and Spencer Financial Services PLC, Marks and Spencer Unit Trust Management Limited, Marks and Spencer Life Assurance Limited and Marks and Spencer Savings and Investments Limited is Kings Meadow, Chester, CH99 9FB. These firms are authorised and regulated by the Financial Services Authority.