Hi all!

We have built a linux router with 4 NIC's (3com 905B's) running on slackware 8.0 with kernel 2.4.9.

eth0 is connected to a 100Mbit Fibre via a Cisco 7100 router.

eth1-3 is connected to various subnets of the half a C-class we have.

When downloading a file to the Router from a nearby site we are able to reach up to 7 Megabytes / second transfer rate, but when downloading from a host connected to eth1-3 we only get between 400-500 Kb/second transfer.

Also, Running game connections like half-life does not produce better ping times than our old 2Mbit E1 connection.

My best guess is that something is badly configured inside the router, the question is - what?

The hosts on the subnets from eth1-3 are connected directly to that network, no firewalls or anything between them.

Any ideas, anyone?

Just a guess out in the wild:

passive NIC's require a lot of CPU-time. Might the four NIC's just be too much for your router to handle at once? -> try if just running one NIC improves network performance.

Well, that is not the issue... we are running a 433 Mhz Celeron (suxeron) with 256 Mb RAM, using about 0.02 load average at any time and with only 19 Mb RAM used...

Interesting problem. This is just an idea but coudl it be that the 400-500k is just a physical limit of the CAT5 cable? Remember the limit on CAT5 is 100megaBIT. I'm sure the limit on fibre is much higher than that.

Second, I am guessing you did this but did you compile the kernel with any of the router options? Don't know the details without looking , but there are some routing algorithms that can be turned on in the kernel. Maybe one of those would help.

Hi..


Disable all unwanted daemons and make the kernel as smal as possible.

Chek a ftp session between ur intranet segmaents (eth1 segment to eth2 segement) . then u can isolate the problem where the probelm exactly.

Try to use some other ftp client and check it. with a single ftp session u wont get full entire bandwidh.ie the one of the propertied of tcp/ip.

Initiate some 5 to 10 ftp request and check how much total throughput u are getting.

the above analysis may help u to sort out this problem.

Which routing protocol u are using ??


Siddiqu.T