One thing I've never quite understood on Linux is what happens to local traffic that isn't directed at loopback.For example, given the following network setup:[root@pe-323-master ~]# ifconfigeth0      Link encap:Ethernet  HWaddr 00:0C:29:2B:59:85          inet addr:172.16.90.133  Bcast:172.16.90.255  Mask:255.255.255.0          inet6 addr: fe80::20c:29ff:fe2b:5985/64 Scope:Link          UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1          RX packets:1881 errors:0 dropped:0 overruns:0 frame:0          TX packets:1205 errors:0 dropped:0 overruns:0 carrier:0          collisions:0 txqueuelen:1000          RX bytes:234047 (228.5 KiB)  TX bytes:134389 (131.2 KiB)eth1      Link encap:Ethernet  HWaddr 00:0C:29:2B:59:8F          inet addr:10.20.2.2  Bcast:10.20.2.255  Mask:255.255.255.0          inet6 addr: fe80::20c:29ff:fe2b:598f/64 Scope:Link          UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1          RX packets:77 errors:0 dropped:0 overruns:0 frame:0          TX packets:18 errors:0 dropped:0 overruns:0 carrier:0          collisions:0 txqueuelen:1000          RX bytes:14880 (14.5 KiB)  TX bytes:1188 (1.1 KiB)lo        Link encap:Local Loopback          inet addr:127.0.0.1  Mask:255.0.0.0          inet6 addr: ::1/128 Scope:Host          UP LOOPBACK RUNNING  MTU:16436  Metric:1          RX packets:13585 errors:0 dropped:0 overruns:0 frame:0          TX packets:13585 errors:0 dropped:0 overruns:0 carrier:0          collisions:0 txqueuelen:0          RX bytes:6501824 (6.2 MiB)  TX bytes:6501824 (6.2 MiB)what actually happens when I ping a local non-loopback address?[root@pe-323-master ~]# ping -c 1 172.16.90.133PING 172.16.90.133 (172.16.90.133) 56(84) bytes of data.64 bytes from 172.16.90.133: icmp_seq=1 ttl=64 time=0.011 ms--- 172.16.90.133 ping statistics ---1 packets transmitted, 1 received, 0% packet loss, time 0msrtt min/avg/max/mdev = 0.011/0.011/0.011/0.000 msDoes that traffic go out over the wire and come back, or is routed internally?
What happens to local LAN traffic on linux to non-loopback addresses?
networking;routing