> For v6, there are plenty of operational reasons to not allow this. You really > turn unicast into anycast when you do this and there are special rules to > be followed.
I don't see it that way. The only "problem" I can think of offhand is that you can't use a multi-interface address to identify an interface (for example, for multicasting) and get predictable results (it'll pick the first one it finds with that address, in no particular order). But you can still use interface indexes, which are unique. Anycast is used for multiple distinct hosts, which isn't an issue on the same host. It's already true, as you pointed out, that you can receive a packet for any local address on any interface, so allowing multiple instances means you still match it as local. Which interface you match it on usually isn't relevant, and when it is are exactly the cases where using duplicates might be appropriate. I can see where it might be useful if you have policy restrictions on some interfaces and want the particular address to be both in and out of a set. But, I agree, it's generally more trouble (for an administrator), but then administrators don't have to assign the same address to multiple interfaces. +-DLS - To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html