Hi, I'm using Harbour 10G lay3 switch which interconnects a Catalyst6509 and a Foundry switch. the interconnecting lines are all 1Gbps ethernet (1000Gb LX). Catalyst6509----Harbour 10G switch----Foundry Switch---Firewall the firewall and harbour interconnect at layer 3. We noticed there is something abnormal on link between 10G switch and Foundry switch: 1. The load on that 1Gbps link may decrease sharply from 110Mbps to 20Mbps and come back, the frequency and occuring time is random. 2. we monitoring connection to Firewall interface by 'ping' with twenty 50byte packets every 20 seconds, and there is packet loss and end-to-end latency increase around the time when link load decreases sharply. 3. on Harbour switch, the interface counter always shows there is "Dropped Packets on Ingress" on interface connecting foundry and cisco, and the number increase continuously. I've disable auto-negotiation and flow-control on between 10G switch and Foundry switch, firewall interface. What's maybe the possible reason for problem above? thanks in advance. Joe __________________________________________________ Do You Yahoo!? Download the latest ringtones, games, and more! http://sg.mobile.yahoo.com