On Mon, 12 Apr 2004 10:00, Joe Bouchard <[EMAIL PROTECTED]> wrote: > In a meeting at work (I'm part of the IT group at a large corporation) > someone mentioned a particular kind of network hardware which would stop > working correctly after a while.
Here are some ways that network issues can slow down a server: On shared media (such as 10base2) accidentally leave an interface in promiscuous mode (there used to be a bug in tcpdump whereby running two copies of it at the same time could cause the interface to remain in promiscuous mode after both copies had exited). A moderately busy 10base2 could destroy the performance of a decent 1995 server machine if an interface was in promiscuous mode, and as the CPU use occurred in interrupt context none of the usual tools would tell you what was happening. Send lots of minimal size packets to a server or to the media broadcast address. Until recently minimal size packets on 10Mb media could destroy the performance of most systems. Now with Gig-E even using 1500 byte packets you can destroy the performance of most systems. If you had a router break and repeatedly send a single IP datagram to your server on a Gig-E link then the likely result would be a dramatic loss of performance. If you suspect this then the best thing to do is run a program to measure system performance on the console and unplug the network cables. -- http://www.coker.com.au/selinux/ My NSA Security Enhanced Linux packages http://www.coker.com.au/bonnie++/ Bonnie++ hard drive benchmark http://www.coker.com.au/postal/ Postal SMTP/POP benchmark http://www.coker.com.au/~russell/ My home page -- To UNSUBSCRIBE, email to [EMAIL PROTECTED] with a subject of "unsubscribe". Trouble? Contact [EMAIL PROTECTED]
