eth0 is connected to the external network where 224.0.23.12 is, while eth1 is connected to my internal network where the subnet 192.168.80.0 is.
I can't ping 224.0.23.12 but I think nobody can while I can ping google dns
aldo@dcerouter:~$ ping 8.8.8.8
PING 8.8.8.8 (8.8.8.
56(84) bytes of data.
64 bytes from 8.8.8.8: icmp_seq=1 ttl=63 time=115 ms
64 bytes from 8.8.8.8: icmp_seq=2 ttl=63 time=56.9 ms
64 bytes from 8.8.8.8: icmp_seq=3 ttl=63 time=55.0 ms
64 bytes from 8.8.8.8: icmp_seq=4 ttl=63 time=53.3 ms
64 bytes from 8.8.8.8: icmp_seq=5 ttl=63 time=54.3 ms
and I can ping my knx/ip device:
aldo@dcerouter:~$ ping 192.168.80.137
PING 192.168.80.137 (192.168.80.137) 56(84) bytes of data.
64 bytes from 192.168.80.137: icmp_seq=1 ttl=128 time=2.84 ms
64 bytes from 192.168.80.137: icmp_seq=2 ttl=128 time=1.75 ms
64 bytes from 192.168.80.137: icmp_seq=3 ttl=128 time=1.79 ms
64 bytes from 192.168.80.137: icmp_seq=4 ttl=128 time=1.70 ms
64 bytes from 192.168.80.137: icmp_seq=5 ttl=128 time=1.74 ms
here are the interfaces
aldo@dcerouter:~$ ifconfig
eth0 Link encap:Ethernet HWaddr 08:00:27:9c:bb:97
inet addr:10.0.2.15 Bcast:10.0.2.255 Mask:255.255.255.0
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
RX packets:963527 errors:0 dropped:0 overruns:0 frame:0
TX packets:530814 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1000
RX bytes:744585766 (744.5 MB) TX bytes:80129911 (80.1 MB)
eth1 Link encap:Ethernet HWaddr 08:00:27:78:71:f1
inet addr:192.168.80.1 Bcast:192.168.80.255 Mask:255.255.255.0
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
RX packets:522962 errors:0 dropped:0 overruns:0 frame:0
TX packets:941368 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1000
RX bytes:62990564 (62.9 MB) TX bytes:1320045366 (1.3 GB