Nate Duehr wrote: > Probably "mommy" just sends out a broadcast packet that all > "children" know to respond to in a certain way. If your LAN were a > class A (e.g. 10.0.0.0/8) it'd take "mommy" a very long time to find > her "children". :-) Nah, probably a broadcast ping or packet. For 10.0.0.0/8, your bcast address would be 10.255.255.255, so send a packet there and every device on that subnet should pick it up. Check the packet over, see if it's valid, and respond to the sender if it is. -- Phil. | Kitsune: Acorn RiscPC SA202 64M+6G ViewFinder philpem@dsl.pipex.com | Cheetah: Athlon64 3200+ A8VDeluxeV2 512M+100G http://www.philpem.me.uk/ | Tiger: Toshiba SatPro4600 Celeron700 256M+40G -- http://www.piclist.com PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist