I’ve been a long time user of IPv6 tunnels from SixXS to provide an access to the IPv6 Internet behind my ISP. These tunnels also allow me to use static IP addresses for my home servers along with static AAAA records and this is cool !

Currently I use several Debian GNU/Linux based soft-routers with two (100 and 1000) Ethernet ports. These are often running on old recycled laptops which consumes around 40 Watts of power at peak level. Next to that the ARM Raspberry Pi platform consumes around 3 Watts of power (though I still have to measure it by myself). So I thought about replacing all my home-routers with those.

However the Raspberry Pi model B uses a SMSC LAN951x chip which includes the USB 2.0 Hub and an 10/100 Ethernet controller on top of it (which is known as smsc95xx in the Linux kernel). My  main concern was that it would not be fast enough to support the IPv6 tunnel at its peak bandwidth of 60Mbps (that is 30Mbps downstream/upstream).

I already use one RPi as an experimental home-router here. Our Internet bandwidth is a bit slow (12Mbps) so the USB-Ethernet  shouldn’t be a problem. I’ve conducted quick tests with IPerf and as you can see the results are pretty good as long as it doesn’t involve I/O on the RPi.

------------------------------------------------------------
Server listening on TCP port 5001
TCP window size: 85.3 KByte (default)
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[  4] local 10.0.0.1 port 5001 connected with 10.0.0.3 port 37373
[ ID] Interval       Transfer     Bandwidth
[  4]  0.0-10.1 sec   114 MBytes  94.4 Mbits/sec
[  5] local 10.0.0.1 port 5001 connected with 10.0.0.3 port 37376
[  5]  0.0-10.1 sec   114 MBytes  94.5 Mbits/sec
[  4] local 10.0.0.1 port 5001 connected with 10.0.0.3 port 37377
[  4]  0.0-10.1 sec   114 MBytes  94.6 Mbits/sec
[  5] local 10.0.0.1 port 5001 connected with 10.0.0.3 port 37378
[  5]  0.0-10.1 sec   114 MBytes  94.5 Mbits/sec