I have a strange issue. Our 6509/sup720 had some performance issues. Traffic traversing the switch was slow, ftp rates were horrible, etc. It didnt matter what servers and what ports were involved. I verified there were NO cabling/interface type issues/errors. When doing MTR's (traceroutes) I could see the higher level of pps that i tried to do the higher rate of dropped packets. I changed the IP unreachable MLS rate limit from 100 to 100000 and the issue went away. This is strange. What does MLS IP unreachable rate limits have to do with FTP and general file transfers? I can understand that it allows high rates of traceroutes, but why does this fix ALL traffic flowing through the switch? I tested this with a different 6509 and I can run the same level of MTR's through it without errors at the default of 100 ip unreachable rate limit. I would really like to understand this better.