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I create a virtual network interface with:

ifconfig eth0:1 netmask

but when I ping the multicast address:


my virtual interface does not respond.


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Are you pinging from the same host that you confgured the virtual interface on? Does any host respond to the ping? Can you ping the ip address of the virtual interface from another host? – joeqwerty Jun 8 '11 at 15:18
yes, everything is on my machine, and the ip addresses that reply to the ping are the ones in the family where my network card gets its ip address from dhcp (172.x.x.x) – peter roytin Jun 9 '11 at 9:24
Please add more information. Post the output of ip addr. BTW: Why should a logical IP answer to a multicast ping? – Nils Jul 27 '11 at 18:46 is disabled by default on linux 2.6+ hosts. From

echo "0" > /proc/sys/net/ipv4/icmp_echo_ignore_broadcasts

I was able to reproduce this with my debian desktop at home:

From my macbook:

$ ping
PING ( 56 data bytes
64 bytes from icmp_seq=0 ttl=64 time=0.227 ms
64 bytes from icmp_seq=0 ttl=64 time=6.676 ms

On my debian box:

# echo "0" > /proc/sys/net/ipv4/icmp_echo_ignore_broadcasts

Then again on the macbook:

$ ping   
PING ( 56 data bytes
64 bytes from icmp_seq=0 ttl=64 time=0.301 ms
64 bytes from icmp_seq=0 ttl=64 time=1.467 ms # my debian box
64 bytes from icmp_seq=0 ttl=64 time=1.924 ms
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