I've just been reading that Tomato handles QoS well, would I run into the same problem even with that?
If you use a newer dd-wrt build you are probably able to get a few more Mbps out of your line, since I fixed a couple of performance brakes in builds around 22000. At least the latest dd-wrt builds are as fast as tomato builds that don't use any special hack or ctf, which will break your qos setup anyways, so yes I don't think there is any build for that unit, that can handle 100Mbps once QOS is used.
Telnet/ssh to the router and run the "top" command. Soft interrupts will be killing your cpu.
The easiest solution is to get a cheap old used router and connect that person through it. Those old G spec models can only handle 30-40mbps without even running QoS. _________________ Read the forum announcements thoroughly! Be cautious if you're inexperienced.
Available for paid consulting. (Don't PM about complicated setups otherwise)
Looking for bricks and spare routers to expand my collection. (not interested in G spec models)
Would there be any way other than using QoS to do what OP is trying to do, to give one IP (or in my case one subnet) absolute preference over everything else?
QoS really seems like overkill for a "give this absolute priority over everything else" case, is there perhaps a way to accomplish this via iptables or something else that doesn't require QoS?
In my case QoS would be a real problem to implement, because my DD-WRT router shares the WAN with a firewall device required for PCI compliance. The restriction that QoS has to be told how much bandwidth is available is kind of a problem because I don't know how much bandwidth there is due to the fact it isn't all going through the DD-WRT router. Most of the time the DD-WRT router would have access to all of it, but at certain (unscheduled) times the firewall device (and the devices behind it) will be hitting the WAN fairly hard.