[vox-tech] different MAC address when using "ifconfig" and "arp"

[Bryan Richter]

Someone correct me if I'm wrong, but a router has to have at least two MAC
addresses, right? Maybe you are seeing the two different eth devices.

2008/4/13, Hai Yi <yihai2004 at gmail.com>:
>
> Thank you, Bryan:
>
> I think you are pretty much correct: it looks like this "arp" command
> is equivalent to another command "ip neighbor", which pretty much
> speaks for itself. However, I checked the MAC on my router, it appears
> to be   00:14:BF:D3:AE:2A, which is one digit greater in the last
> section than the one from arp command. (00:14:BF:D3:AE:29 ) Why is
> that?
>
> Thanks,
>
> Hai
>
>
> On Sun, Apr 13, 2008 at 2:15 PM, Bryan Richter <bryan.richter at gmail.com>
> wrote:
> > 2008/4/13, Hai Yi <yihai2004 at gmail.com>:
> >
> >
> > > Hello,
> > >
> > > I thought I can get my ether card's MAC address by using either
> > > "ifconfig eth0" command or "arp -v" command, but these commands
> > > returned different MAC address(00:16:E6:5C:DA:B8 vs
> > > 00:14:BF:D3:AE:29). Did I miss something here?
> > >
> > > I am using Ubuntu and the following are the results:
> > >
> > >
> > > hai at zodiac:~$ ifconfig eth0
> > > eth0      Link encap:Ethernet  HWaddr 00:16:E6:5C:DA:B8
> > >           inet addr:192.168.1.103  Bcast:192.168.1.255  Mask:
> 255.255.255.0
> > >           inet6 addr: fe80::216:e6ff:fe5c:dab8/64 Scope:Link
> > >           UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
> > >           RX packets:27120 errors:0 dropped:0 overruns:0 frame:0
> > >           TX packets:26884 errors:0 dropped:0 overruns:0 carrier:0
> > >           collisions:0 txqueuelen:1000
> > >           RX bytes:6831509 (6.5 MiB)  TX bytes:3820509 (3.6 MiB)
> > >           Interrupt:16
> > >
> > > hai at zodiac:~$ arp -v
> > > Address                  HWtype  HWaddress           Flags Mask
> > Iface
> > > .                        ether   00:14:BF:D3:AE:29   C
> > eth0
> > > Entries: 1      Skipped: 0      Found: 1
> > >
> > >
> > > Thanks a lot!
> > > Hai
> >
> >
> >  I think arp shows your adapter's neighbors, not the adapter itself. I
> only
> > just read the man page for the first time, however, its results when I
> run
> > it seem to confirm that:
> >
> >  192.168.1.1              ether   00:18:4D:25:82:0D   C
> > ath0
> >
> >  My adapter's neighbor is, indeed, 192.168.1.1 (my router).
> >
> >  ifconfig, on the other hand, seems like a much better place to find
> info
> > about the device, itself. Also, the address it gives for my device
> matches
> > the sticker that the manufacturer put on my laptop. :)
> >
> >  -Bryan
>
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> >
> >
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-- 
Bryan Richter
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