On Fri, 22 Feb 2002, Benjamin Scott wrote: =>On Fri, 22 Feb 2002, Michael O'Donnell wrote: =>> Aren't there two IP broadcast addresses? =>> One consisting of all zeroes and the other all ones? => => Not exactly. => => 255.255.255.255 is the "universal" broadcast address -- any host which =>receives a packet for that address is supposed to process it. Routers are =>not supposed to forward packets to that address. => => Take a network address, and set the "node" part to all ones (binary), and =>you have the broadcast address for that particular IP network. => => The network address with the "node" part set to all zeros (binary) is =>simply the network address. Some early IP implementations used that as the =>broadcast address, but that is not considered "correct". => => For example, take network 192.168.123.0/24. The first three bytes are the =>network part, and the last byte is the node part. Here are the important =>numbers: => =>Net mask 255.255.255.0 11111111.11111111.11111111.00000000 =>Network 192.168.123.0 11000000.10101000.01111011.00000000 =>First node 192.168.123.1 11000000.10101000.01111011.00000001 =>Last node 192.168.123.254 11000000.10101000.01111011.11111110 =>Broadcast 192.168.123.255 11000000.10101000.01111011.11111111 => => There is also the "all subnets" broadcast address which meant something =>more interesting before CIDR/VLSM became common. I'm not sure it is even =>used anymore. It is/was a way to send a packet to all nodes within an =>entire subnet'ed network. For example, take class A network 10.0.0.0/8 and =>subnet it into a bunch of class C networks (10.0.0.0/24, 10.0.1.0/24 ... =>10.255.254.0/24). You could, in theory, send to 10.255.255.255 and get =>every node in the entire class A network. => => The above is subject to being wrong. :-) But it wasn't :-)
Thanks all. -- -Time flies like the wind. Fruit flies like a banana. Stranger things have - -happened but none stranger than this. Does your driver's license say Organ -Donor?Black holes are where God divided by zero. Listen to me! We are all- -individuals! What if this weren't a hypothetical question? [EMAIL PROTECTED] ***************************************************************** To unsubscribe from this list, send mail to [EMAIL PROTECTED] with the text 'unsubscribe gnhlug' in the message body. *****************************************************************
