I'm trying to monitor inbound and outbound traffic using Cacti on Ubuntu Server 14.04.1. I've got it up and running, but the reported data is wrong. When I run 'ifconfig' I get the following:
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:65536 Metric:1
RX packets:84132 errors:0 dropped:0 overruns:0 frame:0
TX packets:84132 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:0
RX bytes:6698322 (6.6 MB) TX bytes:6698322 (6.6 MB)
p3p1 Link encap:Ethernet HWaddr d0:50:99:28:ab:91
inet addr:192.168.1.100 Bcast:192.168.1.255 Mask:255.255.255.0
inet6 addr: fe80::d250:99ff:fe28:ab91/64 Scope:Link
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
RX packets:0 errors:0 dropped:0 overruns:0 frame:0
TX packets:0 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1000
RX bytes:0 (0.0 B) TX bytes:0 (0.0 B)
Interrupt:19
As you can see, all the traffic is going through the loopback interface and the outbound bytes are the same as the inbound bytes. I am not familiar with linux, so I don't know if this is the intended behavior, but it doesn't seem right to me.