At 04:55 AM 8/14/96 -0400, Rabid Wombat <wombat@mcfeely.bsfs.org> wrote:
Most manufacturers offer SNMP-manageable hubs, but these don't offer MAC-layer security. That usually costs a lot extra. The MAC-layer feature is not widely used.
AT&T was about the first vendor with that feature. Aside from solving a _lot_ of potential security problems, it was very convenient for finding out what device really _was_ connected to what hub port - the hub recorded the most recent MAC address received on each port, and you could compare that to ARP tables and untangle lots of problems. Not as fancy as a Sniffer, but let you do things that a Sniffer on ThinWire couldn't. (Of course, since it wasn't NSA-rated, the fact that it actually did solve security problems didn't give us extra slack on government jobs that needed it. ) A multi-port bridge gives you similar security capability, but generally costs more because it needs buffering and much more intelligence; the AT&T SmartHub was a lot simpler and (in its day) cheaper. It was about twice the cost of a regular hub, half the excess from cool features and half because it was from AT&T :-) It was less reliable than the regular hub, because it needed a fan to handle the extra heat from the processor board, and was also more awkward to mount. And the SNMP implementation was rather buggy, though it did have a convenient PC SNMP manager that knew how to use SNMP-over-MAC and the special features of the hub. Cool device. # Thanks; Bill # Bill Stewart, +1-415-442-2215 stewarts@ix.netcom.com # <A HREF="http://idiom.com/~wcs"> Reassign Authority!