Messages in this thread | | | Date | Wed, 27 Jan 1999 10:17:04 -0500 (EST) | From | "Richard B. Johnson" <> | Subject | Re: why broadcast on *.0 (network) addresses ? |
| |
On Wed, 27 Jan 1999, Harald Koenig wrote:
> why do I get > > 64 bytes from 134.2.170.66: icmp_seq=1 ttl=64 time=2.4 ms (DUP!) > > when I run > > ping 134.2.170.0 >
If you ping the network address, you will get a response from every host on your local network! This is correct. Some versions of ping prevent you pinging the network address or a broadcast address.
Script started on Wed Jan 27 10:10:00 1999 # ping 204.178.40.0 PING 204.178.40.0 (204.178.40.0): 56 data bytes 64 bytes from 204.178.40.224: icmp_seq=0 ttl=255 time=0.1 ms 64 bytes from 204.178.47.187: icmp_seq=0 ttl=255 time=1.8 ms (DUP!) 64 bytes from 204.178.40.210: icmp_seq=0 ttl=255 time=1.9 ms (DUP!) 64 bytes from 204.178.40.208: icmp_seq=0 ttl=255 time=1.9 ms (DUP!) 64 bytes from 204.178.40.8: icmp_seq=0 ttl=255 time=2.1 ms (DUP!) 64 bytes from 204.178.47.140: icmp_seq=0 ttl=64 time=2.1 ms (DUP!) 64 bytes from 204.178.45.185: icmp_seq=0 ttl=255 time=2.1 ms (DUP!) [SNIPPED hundreds of responses]
FYI, SNMP (Simplified network management protocol) programs often find the machines that are alive on the local network by doing this.
M$CRAP machines ARP every possible machine, rather than sending one ICMP request and sorting the answers, which makes M$CRAP a bad network neighbor.
Cheers, Dick Johnson ***** FILE SYSTEM WAS MODIFIED ***** Penguin : Linux version 2.1.131 on an i686 machine (400.59 BogoMips). Warning : It's hard to remain at the trailing edge of technology. Wisdom : It's not a Y2K problem. It's a Y2Day problem.
- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.rutgers.edu Please read the FAQ at http://www.tux.org/lkml/
| |