Newsgroups: comp.protocols.tcp-ip Path: utzoo!henry From: henry@zoo.toronto.edu (Henry Spencer) Subject: Re: Ethernet Address Uniqueness... Message-ID: <1990Oct5.195237.2176@zoo.toronto.edu> Organization: U of Toronto Zoology References: Date: Fri, 5 Oct 90 19:52:37 GMT In article linegar@bwdls49.bnr.ca (Derick Linegar) writes: >our vendor eluded to us that the 2 ethernet cards assume the *same* Ethernet >address, obtained from the primary ethernet board. Of course, warning bells >are going of here. Now I've been searching the RFC and IEEE docs and I cannot >find any documentation that sort of says that Ethernet Addresses are assigned >to Ethernet boards, not hosts. This seems to come up fairly often... The original intent of Ethernet was quite specifically to assign addresses to hosts, not boards, which is one reason why Ethernet addresses are required to be programmable instead of being locked into the boards. The XNS protocols use Ethernet addresses as host numbers and *must* have exactly one address per host. With TCP/IP, the Ethernet addresses are largely invisible to the upper levels and it doesn't really matter much either way, unless for some reason you've got two boards on the same network (in which case you will have other problems...). -- Imagine life with OS/360 the standard | Henry Spencer at U of Toronto Zoology operating system. Now think about X. | henry@zoo.toronto.edu utzoo!henry