mea@sparta.com (Mike Anderson) (06/29/90)
Are you aware that when you have two ethernet controllers in a Sun backplane that they have the same 48-bit ethernet address? Yes, Virginia, this may seem a bit strange (and a somewhat undocumented "feature"), but it is true. This caused me (and my machine) some amount of confusion at first. If both ethernet controllers are attached to the same LAN segment, it is possible for the IP addresses to get a bit screwed up when ARP requests go out and two interfaces respond at the same address :-(. However, there is a fix. As root, use the "ifconfig" command and the "ether address family" attribute to change the ethernet address of ie1 (I assume your using ie devices, but this would work for other devices as well) to an unused ethernet address (excercise some caution here to pick a DEFINATELY UNUSED address or the problem will remanifest itself). Sun evidently figured that the only use for two ethernet controllers was to act as a bridge between two completely separate LANs. I also believe that ie1 actually has a separate ethernet address prom (can anyone confirm or deny this?), but at a quick glance I couldn't pick it out on the board. Good Luck... Mike Anderson "It is useless for sheep to pass resolutions in favor SPARTA, Inc. of vegetarianism while wolves remain of a different mea@sparta.com opinion." (703) 448-0210 William R. Inge, D.D. 1860-1954
henry@zoo.toronto.edu (07/01/90)
>Are you aware that when you have two ethernet controllers in a Sun >backplane that they have the same 48-bit ethernet address? ... Sun >evidently figured that the only use for two ethernet controllers was to >act as a bridge between two completely separate LANs... In fact, the original intent of Ethernet addresses was that they were to be *host* numbers, so naturally all interfaces on one host have the same address. This intent has kind of gotten lost, along with the XNS higher-level protocols that exploited this property. Henry Spencer at U of Toronto Zoology henry@zoo.toronto.edu utzoo!henry