My system is configured in such a way to respond for ICMP broadcast and multicast requests from outside our network. Below command will give the details:
server1:~# ndd -get /dev/ip ip_respond_to_echo_multicast -> 1
server1:~# ndd -get /dev/ip ip_respond_to_echo_broadcast -> 1
server1:~# ndd -get /dev/ip ip6_respond_to_echo_multicast -> 1
It means currently it is enabled to respond to ICMP broadcast and multicast requests.
Command to get system interface broadcast address is ifconfig –a and command to get system interface multicast address is arp –a.
server:~# ifconfig -a
lo0: flags=2001000849<UP,LOOPBACK,RUNNING,MULTICAST,IPv 4,VIRTUAL> mtu 8232 index 1
inet 127.0.0.1 netmask ff000000
ce3: flags=1000843<UP,BROADCAST,RUNNING,MULTICAST,IPv4> mtu 1500 index 3
inet 10.0.1.1 netmask ffffff00 broadcast 10.191.2.255
server:~# arp -a
Net to Media Table: IPv4
Device IP Address Mask Flags Phys Addr
ce3 server1 255.255.255.255
ce3 server2 255.255.255.255 SPLA
ce5 server3 255.255.255.255 SPLA
ce4 server4 255.255.255.255 SPLA
ce5 126.96.36.199 240.0.0.0 SM
ce4 188.8.131.52 240.0.0.0 SM
ce3 184.108.40.206 240.0.0.0 SM
Note: M indicates it is the multicast address used by that interface.
> If I tried sending ICMP request to multicast address by following command: ping 220.127.116.11 from my laptop, I didn’t get response from server1. (as the above parameters are enabled, I need to get response)
> If I tried sending ICMP request to broadcast address by following command: ping 10.191.2.255 from my laptop, I didn’t get response from server1. (as the above parameters are enabled, I need to get response)