not debian specific: strange routing using 3 lines
I have a question concerning routing under Linux. It is not Debian
specific, but maybe some people here can give me a hint... :)
I run an NAT server with Linux (Slackware) Kernel 2.2.17.
I have 3 ADSL-lines attached to the machine.
The default route is set to Line 1, some subnets are set to line 2 and 3 to
balance the traffic a bit (i.e. 220.127.116.11/8 to line 2 and 18.104.22.168/8 to
Now I have the situation that the default line is still too busy, but most
traffic is going to the networks which point to line 2 and 3.
I checked the routing on that machine using traceroute to trace some ips in
For example in 22.214.171.124/8 which pionts to line 2, still some destination
ips are routed to the default line. Others in the same network are routed
correctly. The same situation for the other subnet on line 3. Some packets
are routed correctly depending on their destination ip, others are not.
I thought maybe the kernel stored the wrong route in the internal routing
table and then just kept it, so I flushed it by
echo 1 > /proc/sys/net/ipv4/route/flush
but still no changes. can someone give me a hint?