You donot need root privelegs to just run 'ifconfig'. You will need the privelege only when you are about to set some values using it. Below is the output from my server.
Code:
<ravip@lfx1> (Tue Aug 24 08:03:59) [/netsim/bsdnfs05/ravip]
$ /sbin/ifconfig
eth0 Link encap:Ethernet HWaddr 00:40:F4:51:39:2E
inet addr:10.1.172.150 Bcast:10.1.175.255 Mask:255.255.252.0
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
RX packets:8142793 errors:0 dropped:0 overruns:0 frame:0
TX packets:8951145 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:100
RX bytes:329376235 (314.1 Mb) TX bytes:2539672855 (2422.0 Mb)
Interrupt:17 Base address:0x5000
lo Link encap:Local Loopback
inet addr:127.0.0.1 Mask:255.0.0.0
UP LOOPBACK RUNNING MTU:16436 Metric:1
RX packets:1392814 errors:0 dropped:0 overruns:0 frame:0
TX packets:1392814 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:0
RX bytes:99483472 (94.8 Mb) TX bytes:99483472 (94.8 Mb)
All you have to do is to run '/sbin/ifconfig'.
'arp' will give you the MAC address of all the neighbour nodes as well.