On Fri, 13 Feb 1998, Randy Bush wrote: ==>> o All router administrators on the immediately reachable ==>> Internet needs to turn off directed broadcasts on their router ==>> interfaces. It's conceivable that "a significant portion of ==>> all" would do as well, but the magnitude of this problem ==>> boggles the mind. First of all, we'd need to distribute the ==>> appropriate amount of clue to all the corners of the net where ==>> this needs to happen. Maybe, just maybe, we'll get there ==>> sometime (I'm an optimist!). ==> ==>why should this not have become the default mode for all vendor ==>diustributed router code? Because the routing RFC[1] states: --- A router MAY have an option to disable receiving network-prefix- directed broadcasts on an interface and MUST have an option to disable forwarding network-prefix-directed broadcasts. These options MUST default to permit receiving and forwarding network-prefix- directed broadcasts. --- "network-prefix-directed broadcasts" are the ones spoken of here. A router *MUST* have an option to turn them off and *MUST* default to forwarding them. The "MAY" stated here (to clarify) means that the router MAY choose not to respond to another host pinging a broadcast address. [1] RFC-1812, "Requirements for IP Version 4 Routers"; F. Baker; June 1995. /cah