Hi! I have a network in my office (With Linux + Win Desktops, some are thin clients). I am facing a strange problem. I am having a dlink hub(8 port) and dlink switch(16 port). Both are connected with crossover cable. Machines connected to the hub can ping each other properly. But when i ping a machine which is connected to a switch i get packet loss. Also small packet ping is ok, but when i increase the packet size, the data loss occurs :( ping -s 40000 <to a switch machine> = loss ping <to a switch machine> = OK ping <to a machine in same hub> = Excellent. Switch to Switch is also OK. I have changed cross over cable but its the same... And this same structure worked a few days ago fine! Another hint for me was that, when i connect the cross over cable to the switch, the collision LED on the hub blinks a lot.. Otherwise its off. Please Help. --Anand.

is the switch managed?

I'm a little confused, you typed "- s" but that's a timestamp for hop counts in which the max value you can have is "4", you can't have "40000". I'm trying to figure out did you typo the wrong tag or the value? If you are inputing a value of packet size, which is "- l", and occuring packet loss then the most likely problem with your switch is a mis-config of MTU. Most MTUs are set to a value of under 1500 which coincides with max ratio of size of transmission unit to acknowledgements in TCP...any bigger and you make what's called giants...this is as bad as fragmenting... Try the test setting at 1500. If no loss you really don't have a problem, but if you're still concerned try looking for MTU settings within the switch. "Is the switch managed?" - Mike you're too much...the guy is buying dlinks for his home office for crying out loud...though not outside the realm of reality...it's a much distance chance he's using a managed switch dont you think? LOL - all in good humor. D

"Both are connected with crossover cable." No, between hub-hub or hub-switch, cossover cable can not be used. You have to use the regular Ethernet cable. CossOver cable only can be used to connect between 2 Machine directly. Hope this will help

niceGuy - what the "bleep" are you talking about! 1.) Current technology - most switches now have auto-detect Midi/Mdi-X cable type which eliminates the need or concern for st8 thru or x-over cable concerns. 2.) Past technology - like devices connecting to like devices DO NEED a cross-over. Because the cable pins of same devices would make Transmitt connect to Transmitt and Receive to Receive if you don't use a cross-over. 3.) How are you accounting for the fact that he says he can connect as lower packet sizes? Some advise on this board really sucks.

alot of new hubs/switches are designed to handle oversized pings....it drops them due to a ping of death vuln. that came out years ago. i don't know if that is what your running into or not?? Just a guess

Check your pc's nic card settings on the switch , most of these cheap switches only know auto for speed and duplex, if you have hardcoded the nic speed/duplex on the nic then your are going to have a mismatch and slow response times and dropped packets . Set the nics to auto and reboot the machine and try again .