I have a small wired home network. I plugged a nat box, specifically a
SMC 7004VBR Barricade, into a cable modem. Its internal address is
192.168.155.1. Behind this, there are two clients running windows xp
home edition sp2 and one client running freebsd.

The windows clients are able to access the internet, and although ping
times are good, downloading is very slow. Images take a long time to
load during web browsing, there are lag spikes during gaming, and ftp
downloads start at about 6k/sec then stall out.

On the other hand, the freebsd machine works perfectly fine behind nat.
There are no issues with firefox, and files regularly download at over
100k/sec.


Sample traceroute:

Tracing route to www.l.google.com [64.233.161.99]
over a maximum of 30 hops:

1 1 ms 1 ms 1 ms . [192.168.155.1]
2 21 ms 25 ms 11 ms 10.72.224.1
3 24 ms 18 ms 35 ms dstswr1-vlan2.rh.rndhnj.cv.net
[67.83.249.161]
4 62 ms 20 ms 22 ms r1-ge9-2.mhe.prnynj.cv.net
[67.83.249.129]
5 25 ms 29 ms 17 ms r1-srp13-0.wan.prnynj.cv.net
[65.19.112.17]
6 25 ms 12 ms 17 ms r2-srp13-0.in.nycmnyzr.cv.net
[65.19.96.136]
7 32 ms 30 ms 48 ms r1-pos3-0.in.asbnva16.cv.net
[65.19.97.226]
8 * * * Request timed out.
9 20 ms 35 ms 25 ms 216.239.47.153
10 24 ms 28 ms 33 ms 216.239.49.214
11 44 ms 31 ms 23 ms www.l.google.com [64.233.161.99]



The second hop with the 10.x.x.x address apparently comes from my isp,
not my home network.

Also note that if I plug the cable modem directly into one of the
windows xp machines, everything works fine, and there are no slowdowns.
Any suggestions?