[Freemint-list] Slow network speed

[Markus Fröschle]

Just found another thing within my network that might or might not 
affect you as well, depending on your network setup.

My setup is in a way that all my computers (including my MiNT machines) 
that are on a wired connection are plugged to a (24 port) switch under 
my desk. This is connected to my DSL router (through powerline adapters, 
because its located elswhere where I have no cabling) that also acts as 
DHCP server.

This ends up in a situation (because of the powerline circuit) where the 
connection to my router is much slower (but usually still more than fast 
enough for the DSL bandwidth) than to any other computer.

During my wireshark sessions, I have observed that MiNT always directed 
its outgoing packets to the router (which is bad since this is obviously 
the slower path than just going through the attached switch), while all 
other computers on the switch just directly addressed them to the target 
computer.

It turned out it was caused by the routes set by the DHCP client. What I 
got from the DHCP client was

-bash-4.3# route
Destination         Gateway             Flags   Ref      Use Metric Iface
default             192.168.1.1         UGD       1       11      0 eth0
192.168.1.102       *                   UH        1   437494      0 lo0
127.0.0.0           *                   U         1        0      0 lo0
127.0.0.1           *                   UH        1    68069      0 lo0

while what I needed was this:

-bash-4.3# route
Destination         Gateway             Flags   Ref      Use Metric Iface
default             192.168.1.1         UGD       1       11      0 eth0
192.168.1.102       *                   UH        1   437494      0 lo0
192.168.1.0         *                   UD        1   226406      0 eth0
127.0.0.0           *                   U         1        0      0 lo0
127.0.0.1           *                   UH        1    68069      0 lo0

(the direct route to the interface was missing). This appears to be MiNT 
specific (all my other machines set this correctly without manual fumbling).

You might want to check this if you are not using your gateway as a 
switch. For me, adding the missing route manually resulted in an iperf 
performance gain of more than 20%.