broad.cast (brôd'kăst') v., -cast or -cast.ed, -cast.ing, -casts.
v.tr. To transmit (a radio or television program) for public or general use. To send out or communicate, especially by radio or television: The agency broadcast an urgent appeal for medical supplies. To make known over a wide area: broadcast rumors. See synonyms at announce. To sow (seed) over a wide area, especially by hand. Pretty much that's what a broadcast is - a packet directed to everyone instead of to a particular address. Or it can be a packet sent 'from everyone' - which is less common and somewhat suspicious. Common broadcasts are DHCP (think - how to you give the DHCP server your IP address for replies when you don't yet have one? Answer - packet originates from 'broadcast') Every subnetwork has a broadcast address, it's the all 1s. So 192.168.0.0/24's broadcast is 192.168.0.255 etc. Also 255.255.255.255 is used. DNS shouldn't be broadcast ... that just smells odd... You probably need to post a few packet captures so we can see what's up - maybe take this to ntop-misc as it's not really ntop related... -----Burton -----Original Message----- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Kenneth Porter Sent: Tuesday, June 07, 2005 4:27 PM To: ntop users Subject: [Ntop] Broadcast? What does "broadcast" mean in the RRD graphs? I found that "tcpdump ip broadcast" also tags a lot of packets that don't appear to be from or to an IP broadcast address. I'm seeing a lot of DNS traffic tagged as broadcast (about half the total), as well as a lot of UDP game packets to specific clients. What am I missing? (I also found I'm getting a ton of arp's from outside the subnet, so I need to pester the guy running the router to deal with those.) _______________________________________________ Ntop mailing list [email protected] http://listgateway.unipi.it/mailman/listinfo/ntop _______________________________________________ Ntop mailing list [email protected] http://listgateway.unipi.it/mailman/listinfo/ntop
