latency

I have an issue with a Win2k Adv Server running routing and nat. There are 2 linux boxes, 5 apc’s ( 10baseT connections), 1 MAX attach storage running a modified version of win2k server, on the segment.

The issue is poor network performance,
theobvious has been checked (cables, nic settings, dns ). Pings are normal, however traceroute returns high latency through a couple of core routers (300msec). Small packets get through but having problems with large ones.