ifconfig and carier

[sybvn]

Hi all,

I want to understand the carrier field in the result of ifconfig command. So far I know carrier is a signal which indicates the present of physical connection on Ethernet port. Does it have this same meaning in ifconfig result? And if I see on my PC like

#ifconfig
eth0 Link encap:Ethernet HWaddr 00:0C:6E:4C:FC:5F
inet addr:192.168.123.11 Bcast:192.168.123.255 Mask:255.255.255.0
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
RX packets:22526 errors:0 dropped:0 overruns:0 frame:0
TX packets:6196 errors:0 dropped:0 overruns:0 carrier:6196
collisions:0 txqueuelen:100
RX bytes:4006671 (3.8 Mb) TX bytes:1003982 (980.4 Kb)
Interrupt:10 Memory:ed000000-ed001080

Then what does the number 6196 mean? I already read ifconfig manual page but found no information.

Thanks in advance

[rjdkolb]

Hi Hi,

I can honestly say I don't know, but I do understand your confusion because I have been confused about this for ages.

In FreeBSD I always know if there is a cable connected
------------------------
Under FreeBSD 4.9 you will get this from a ifconfig


ether0: flags=8943<UP,BROADCAST,RUNNING,PROMISC,SIMPLEX,MU LTICAST> mtu 1500
inet6 fe80::202:b3ff:fed1:3cf0%ether0 prefixlen 64 scopeid 0x1
ether 00:02:b3:d1:3c:f0
media: Ethernet autoselect (100baseTX <full-duplex>)
status: active
ether1: flags=8943<UP,BROADCAST,RUNNING,PROMISC,SIMPLEX,MU LTICAST> mtu 1500
inet6 fe80::202:b3ff:fed1:3cf9%ether1 prefixlen 64 scopeid 0x2
ether 00:02:b3:d1:3c:f9
media: Ethernet autoselect (none)
status: no carrier
------------------------
I could nerver understand why my Linux box says

eth0 Link encap:Ethernet HWaddr 00:80:AD:77:8A:F7
inet addr:10.7.146.204 Bcast:10.7.146.255 Mask:255.255.255.0
inet6 addr: fe80::280:adff:fe77:8af7/64 Scope:Link
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
RX packets:3509050 errors:336 dropped:0 overruns:335 frame:335
TX packets:3395885 errors:1 dropped:0 overruns:0 carrier:0
collisions:429408 txqueuelen:1000
RX bytes:2701089194 (2575.9 Mb) TX bytes:565276461 (539.0 Mb)
Interrupt:10 Base address:0xdc00
------------------------

[swemic]

It is actually implementation dependent, however, A.F.I.K. carrier means that you have had such number of carrier lost since you did your last if-dwn / if-up. This value should represantate the number of packets that you have sent out-of-the-blue.