dave@rosesun.Rosemount.COM (Dave Marquardt) (01/14/88)
While using the MIT PC/IP "netwatch" program, I looked at the Ethernet statistics and found we were getting a number of "overflows". Can someone define "overflow" for me in terms of Ethernet? Or point me to a reference that defines "overflow"? Thanks.
romkey@kaos.UUCP (John Romkey) (01/15/88)
In article <3915@rosesun.Rosemount.COM> andy@rosevax.Rosemount.COM (Andy Barnhouse) writes: >While using the MIT PC/IP "netwatch" program, I looked at the Ethernet >statistics and found we were getting a number of "overflows". Can someone >define "overflow" for me in terms of Ethernet? Or point me to a reference >that defines "overflow"? Thanks. What netwatch is refering to as an "overflow" is your ethernet card missing a packet. You're almost certainly using a 3COM 3C501 or a Micom-Interlan NI5010 ethernet board, neither of which are too swift. It's pretty easy to get them to miss packets. These boards each have one buffer to hold incoming data, so if the buffer isn't free by the time the next packet arrives, they miss it. Sometimes they even manage to notice that they miss it, and then they generate the overflow error. Sometimes they don't notice, too. If this is a problem for you (on a busy ethernet you're likely to miss a lot of stuff) you might want to get a faster ethernet board, like the Micom-Interlan NI5210 or the Western Digital WD8003. The problem is that the free version of PC/IP only supports the 3C501 and the NI5010, so you'll either have to write your own driver or buy a piece of commercial software. FTP Software, Inc., sells a commercial version of Netwatch which supports quite a few much faster ethernet cards. [spoiler alert: I'm pretty heavily involved with FTP Software] Their phone number is (617) 868-4878 if you want to get more info. There are also several other vendors who sell network monitors, like Excelan, Network General and Hewlett-Packard. -- - john romkey ...harvard!spdcc!kaos!romkey romkey@kaos.uucp romkey@xx.lcs.mit.edu