netbsd 5 and high speed internet

["Michael D. Spence" <spence%panix.com@localhost>]

I have been using an old 1ghz 1 or 2Mb PC to run netbsd 5 and act as a
firewall for a number of years.  It is not used for anything but this and
has been working great, until yesterday when I upgraded my cable modem to
100 Mbs.  If I run a speed test on a windows machine inside the firewall,
things are usually really slow (although I have seen 35 Mbs) whereas if I
plug the windows machine directly into the cable modem, I get speeds in the
mid 80s to mid 90s.

Is there any tuning I should try or a place I can read about this?  Here are
the NICs I have:


ex0: flags=8a63<UP,BROADCAST,NOTRAILERS,RUNNING,ALLMULTI,SIMPLEX,MULTICAST>
mtu 1500
        address: 00:60:08:9a:53:6c
        media: Ethernet 100baseTX full-duplex
        status: active
        inet 192.168.0.4 netmask 0xffffff00 broadcast 192.168.0.255
        inet6 fe80::260:8ff:fe9a:536c%ex0 prefixlen 64 scopeid 0x2
vr0: flags=8843<UP,BROADCAST,RUNNING,SIMPLEX,MULTICAST> mtu 1500
        address: 00:24:01:08:93:22
        media: Ethernet 100baseTX full-duplex
        status: active
        inet 192.168.1.6 netmask 0xffffff00 broadcast 192.168.1.255
        inet6 fe80::224:1ff:fe08:9322%vr0 prefixlen 64 scopeid 0x3

ex0 faces the work, vr0 is on my internal network.