This may also shed some light, from sudo ifconfig -a
eth1 Link encap:Ethernet HWaddr 00:xx:xx:xx:xx:xx
inet6 addr: fe80::20c:f1ff:feb0:6641/64 Scope:Link
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
RX packets:27856 errors:3228 dropped:0 overruns:0 frame:3228
TX packets:28934 errors:0 dropped:0 overruns:0 carrier:9
collisions:13 txqueuelen:1000
RX bytes:14163542 (14.1 MB) TX bytes:5419179 (5.4 MB)
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:648 errors:0 dropped:0 overruns:0 frame:0
TX packets:648 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:0
RX bytes:37344 (37.3 KB) TX bytes:37344 (37.3 KB)
pan0 Link encap:Ethernet HWaddr 16:41:0a:56:53:bf
BROADCAST 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:0
RX bytes:0 (0.0 B) TX bytes:0 (0.0 B)
ppp0 Link encap

oint-to-Point Protocol
inet addr:41.213.8.80 P-t-P:aaa.aaa.aaa.aaa Mask:255.255.255.255
UP POINTOPOINT RUNNING NOARP MULTICAST MTU:1392 Metric:1
RX packets:5984 errors:0 dropped:0 overruns:0 frame:0
TX packets:6199 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:3
RX bytes:2458317 (2.4 MB) TX bytes:1252962 (1.2 MB)
3228 frame errors on eth1 seems a bit worrying.