[PLUG] Firewall/router performance

[Tyrell Jentink]

I have Comcast, when connected directly to their modem, I get 50Mbps down,
5Mbps up. I also get that speed through a gigabit switch and my Netgear AP,
seemingly ruling out any problems in my end-to-end connection.

I have been trying to use an old HP Mini 100 as my firewall/router; Atom
processor, 1GB of RAM, Fedora 21, providing NAT/Firewalld/DHCP/DNS. It has
a built-in Ethernet card that I'm using on the external network, and a USB
to Ethernet adapter on the internal network. Both cards are rated 100mbps,
and ethtool shows them as using that speed.

However, FROM the HP, speedtest only comes in at 27Mbps... And with that
computer in the chain (Comcast > HP Mini > Gigabit switch > Netgear AP), I
only get 5Mbps down, 3 up. Removing the gigabit switch and Netgear gives
the same results, seemingly indicating the problem is with the HP.

But WHY? I didn't expect full speed out of the USB device... But if ethtool
is telling the truth, I'd expect it to have little problem passing 50Mbps
of traffic. Even if I was just getting the 27Mbps, I would be less inclined
to complain...

So is the problem something I can fix, or am I running into USB bus (or
some other hardware) issues? I have piles of computers... I could easily
switch to a P4 with 2 gigabit cards... That just seems like so much
overkill.