맥어드레스 6바이트중 앞 3바이트는 벤더별로 할당되어 있는 고유의 코드로 MAC만으로 어느벤더인지 확인이 가능합니다.

eth0      Link encap:Ethernet  HWaddr 00:14:2A:E4:40:F7
          inet addr:218.236.115.225  Bcast:218.236.115.255  Mask:255.255.255.192
          inet6 addr: fe80::214:2aff:fee4:40f7/64 Scope:Link
          UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
          RX packets:7203868 errors:0 dropped:0 overruns:0 frame:0
          TX packets:3728536 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:1000
          RX bytes:2141190432 (1.9 GiB)  TX bytes:277068159 (264.2 MiB)
          Interrupt:18 Base address:0xec00

eth1      Link encap:Ethernet  HWaddr 00:30:4F:4E:70:6C
          inet addr:192.168.10.1  Bcast:192.168.10.255  Mask:255.255.255.0
          inet6 addr: fe80::230:4fff:fe4e:706c/64 Scope:Link
          UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
          RX packets:9760424 errors:0 dropped:0 overruns:0 frame:0
          TX packets:18921285 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:1000
          RX bytes:756017815 (720.9 MiB)  TX bytes:2197268801 (2.0 GiB)
          Interrupt:19 Base address:0x4c00

아래싸이트를 통해서 확인 가능가능합니다.
http://standards.ieee.org/regauth/oui/index.shtml