ping -b

sysslack · 05-26-2008, 02:39 PM

I tried simple syntax according to the man page on my slackware 12 system
ping -b 192.168.0.255

but got no reply.

And I wonder if it is possibly to enable ping broadcast just for my home lab in linux, or do I have to compile a new kernel for accepting broadcast request.

It has nothing to do with firewall rules. I can ping my hosts in ordinary way

unixfool · 05-26-2008, 03:43 PM

Quote:

Originally Posted by sysslack

I tried simple syntax according to the man page on my slackware 12 system
ping -b 192.168.0.255

but got no reply.

And I wonder if it is possibly to enable ping broadcast just for my home lab in linux, or do I have to compile a new kernel for accepting broadcast request.

It has nothing to do with firewall rules. I can ping my hosts in ordinary way

What result are you looking for? Are you trying to map out your network, or trying to conduct/emulate a smurf attack?

I did the same thing and got results, although I didn't get responses from every IP on the network:

Code:

root@slackbox:~# ping -b 10.150.1.255
WARNING: pinging broadcast address
PING 10.150.1.255 (10.150.1.255) 56(84) bytes of data.
64 bytes from 10.150.1.1: icmp_seq=1 ttl=64 time=2.72 ms
64 bytes from 10.150.1.1: icmp_seq=2 ttl=64 time=0.872 ms
64 bytes from 10.150.1.1: icmp_seq=3 ttl=64 time=0.843 ms
64 bytes from 10.150.1.1: icmp_seq=4 ttl=64 time=0.836 ms
64 bytes from 10.150.1.1: icmp_seq=5 ttl=64 time=0.837 ms
64 bytes from 10.150.1.1: icmp_seq=6 ttl=64 time=0.829 ms
64 bytes from 10.150.1.1: icmp_seq=7 ttl=64 time=0.833 ms
64 bytes from 10.150.1.1: icmp_seq=8 ttl=64 time=0.831 ms

It appears that the impact of pinging the broadcast has been lessened considerably. Maybe checking your arp cache after such broadcast pinging may help determine what hosts are live within the network segment...

sysslack · 05-27-2008, 11:55 AM

Thank you for your reply!

sysslack · 05-27-2008, 12:17 PM

Thank you for your reply! I understand it is not god to do but if I want to understand networking better. Then I want to test it on my own network, not just read the theory.So it would be valuable to know how to activate it!

unixfool · 05-27-2008, 12:28 PM

Quote:

Originally Posted by sysslack

Thank you for your reply! I understand it is not god to do but if I want to understand networking better. Then I want to test it on my own network, not just read the theory.So it would be valuable to know how to activate it!

The several pages I visited yesterday hint that kernel code was implemented to lessen the impact of smurf attacks, which is probably why my test results look the way they do.

I suggest perusing Google, just as I did. This isn't a cop-out but just an honest suggestion. All I did was google a bit using the keywords "ping -b" and "ping broadcast"...I got a ton of very good hits.