On March 2, 2004 08:13 am, Marty Landman wrote: > At 08:48 PM 3/1/2004, Pete Nesbitt wrote: > >ping cannot resolve a name, it can resolve a name to IP prior to sending > >the packet, but it really doesn't care about names. > > So I can say ping -c1 penguin instead of ping -c1 192.168.0.160 if I > already know the names of all my boxes on the lan. But what I want to do is > have a way to find all those boxes, ip addr and host name. The host cmd > seems fine for this, i.e. I've modified the script to run `host` for each > ip adr found on the lan, though I haven't finished parsing it yet. > > >You may want to look at 'ping -b' so send a broadcast ping, then collect > >the results. > > I don't understand the man page, could you give an example please? I'd like > to ping everything for > > 192.168.0. with netmask 255.255.255.0 > > This is what I'm doing with the script now in fact, only I realize it's > probably the hard way. At least I learned a little bash and awk though. > > >won't help the name resolution at all. > > But doing a host for each pingable ip works fine tbh so I'm happy with > that. > > This script could actually be used to put together canonical hosts files, > although it'd be lacking in hosts other than the server name for apache > virtual hosts... hope I'm saying that right. > > Marty Landman Face 2 Interface Inc. 845-679-9387 > FormATable DB: http://face2interface.com/Products/FormATable.shtml > Make a Website: http://face2interface.com/Home/Demo.shtml > Free Formmailer: http://face2interface.com/Products/Formal.shtml Hi Marty, to ping the 192.168.1.0/24 network use: ping -c1 -b 192.168.1.255 (just use the broadcast ip for the network) This will not work across a router. It also appears to show all but the primary system as duplicates packets, which would be bad, except that we are pinging the whole lan. Here is a sample, but I only have 2 systems that are pingable (paranoia): pete@nebula temp$ ping -c1 -b 192.168.1.255 WARNING: pinging broadcast address PING 192.168.1.0 (192.168.1.0) 56(84) bytes of data. 64 bytes from 192.168.1.50: icmp_seq=0 ttl=64 time=0.061 ms 64 bytes from 192.168.1.4: icmp_seq=0 ttl=64 time=0.192 ms (DUP!) Do you have a local dns server? I beleive you need a reverse DNS lookup for the 'host' command name to work. If you have a local dns server for the LAN, then try this: (mine fails as I have no reverseDNS) I set this not to wrap, but your email client may... 1st: test at command line: pete@nebula temp$ ping -c1 -b 192.168.1.255 2>/dev/null|grep "^64"|awk '{print $4}'|awk -F: '{print $1}'>>/tmp/ip_numbers pete@nebula temp$ while read IP_NUM; do host $IP_NUM; done < /tmp/ip_numbers Host 50.1.168.192.in-addr.arpa not found: 3(NXDOMAIN) Host 4.1.168.192.in-addr.arpa not found: 3(NXDOMAIN) pete@nebula temp$ so in a script: LAN_BDCAST="192.168.1.255" IP_NUMBERS=/tmp/ip_numbers IP_HOST_FILE=/tmp/ip_2_hostnames echo "">$IP_NUMBERS echo "">$IP_HOST_FILE ping -c1 -b $LAN_BDCAST 2>/dev/null|grep "^64"|awk '{print $4}'|awk -F: '{print $1}'>>$IP_NUMBERS while read IP_NUM do host $IP_NUM >> $IP_HOST_FILE done <$IP_NUMBERS ...you get the idea. Expanding your script to create the named files would be a great exersice, however, it would be of questionable value, because as I see it, you will need to have the DNS & reverseDNS working before you can retreive the names to match to IP's. I don't know how you could get the Virtual Hosts if they are name based. They do need to be in DNS, so if you knew all the VH's you could ping the name to get the IP, but that is a different script again. The thing is you can only ping an IP, (pinging a name just causes a dns lookup prior to the ping) and the name based virtual host aspect is relavent to Apache and to DNS (or /etc/hosts), not the IP address. Hope that helps. -- Pete Nesbitt, rhce -- redhat-list mailing list unsubscribe mailto:redhat-list-request@xxxxxxxxxx?subject=unsubscribe https://www.redhat.com/mailman/listinfo/redhat-list
