# Additional  network interfaces after building the kernel

## krax

I recently build gentoo-3.10.7-gentoo-r1 and after reboot i got some network interfaces AND I don't know IF i NEED THEM EVEN;

Please tell me if any or all of them are useful . also I want to find out which kernel feature; that I enabled ; make each one of them, in order to disable them.

By the way i build in the kernel the ability of .config file

```

     Name                          RX                         TX                             

DENNE (local)                    Rate          #   %        Rate          #   %                   

  0   gre0                         0 B                0            0 B         0

  1   wlp5s0                    1.90KiB           2          256 B         2

  2   dummy0                       0 B           0            0 B         0

  3   lo                             0 B               0            0 B         0

  4   gretap0                      0 B             0            0 B         0

  5   enp3s0                       0 B            0            0 B         0

  6   sit0                         0 B               0            0 B         0

  7   tunl0                        0 B             0            0 B         0

  Total                         1.90KiB          2          256 B         2

                                                     

                                                     
```

 only lo and wlp5s0 are the devices that i had before.  Also in 3.8 kernel my Ethernet (eth0) didn't have the driver (CONIG_ALX) So there should be an eth0 there but in new naming paradigm. ( i guess it is enp3s0).                                                    

```
~# iconfig -a

dummy0: flags=130<BROADCAST,NOARP>  mtu 1500

        ether d6:95:29:56:de:9f  txqueuelen 0  (Ethernet)

        RX packets 0  bytes 0 (0.0 B)

        RX errors 0  dropped 0  overruns 0  frame 0

        TX packets 0  bytes 0 (0.0 B)

        TX errors 0  dropped 0 overruns 0  carrier 0  collisions 0

enp3s0: flags=4098<BROADCAST,MULTICAST>  mtu 1500

        ether 08:60:6e:d3:74:85  txqueuelen 1000  (Ethernet)

        RX packets 0  bytes 0 (0.0 B)

        RX errors 0  dropped 0  overruns 0  frame 0

        TX packets 0  bytes 0 (0.0 B)

        TX errors 0  dropped 0 overruns 0  carrier 0  collisions 0

        device interrupt 16  

gre0: flags=128<NOARP>  mtu 1476

        unspec 00-00-00-00-00-00-00-00-00-00-00-00-00-00-00-00  txqueuelen 0  (UNSPEC)

        RX packets 0  bytes 0 (0.0 B)

        RX errors 0  dropped 0  overruns 0  frame 0

        TX packets 0  bytes 0 (0.0 B)

        TX errors 0  dropped 0 overruns 0  carrier 0  collisions 0

gretap0: flags=4098<BROADCAST,MULTICAST>  mtu 1476

        ether 00:00:00:00:00:00  txqueuelen 1000  (Ethernet)

        RX packets 0  bytes 0 (0.0 B)

        RX errors 0  dropped 0  overruns 0  frame 0

        TX packets 0  bytes 0 (0.0 B)

        TX errors 0  dropped 0 overruns 0  carrier 0  collisions 0

lo: flags=73<UP,LOOPBACK,RUNNING>  mtu 65536

        inet 127.0.0.1  netmask 255.0.0.0

        inet6 ::1  prefixlen 128  scopeid 0x10<host>

        loop  txqueuelen 0  (Local Loopback)

        RX packets 118  bytes 8460 (8.2 KiB)

        RX errors 0  dropped 0  overruns 0  frame 0

        TX packets 118  bytes 8460 (8.2 KiB)

        TX errors 0  dropped 0 overruns 0  carrier 0  collisions 0

sit0: flags=128<NOARP>  mtu 1480

        sit  txqueuelen 0  (IPv6-in-IPv4)

        RX packets 0  bytes 0 (0.0 B)

        RX errors 0  dropped 0  overruns 0  frame 0

        TX packets 0  bytes 0 (0.0 B)

        TX errors 0  dropped 0 overruns 0  carrier 0  collisions 0

tunl0: flags=128<NOARP>  mtu 0

        tunnel   txqueuelen 0  (IPIP Tunnel)

        RX packets 0  bytes 0 (0.0 B)

        RX errors 0  dropped 0  overruns 0  frame 0

        TX packets 0  bytes 0 (0.0 B)

        TX errors 0  dropped 0 overruns 0  carrier 0  collisions 0

wlp5s0: flags=4163<UP,BROADCAST,RUNNING,MULTICAST>  mtu 1500

        inet 192.168.1.100  netmask 255.255.255.0  broadcast 192.168.1.255

        inet6 fe80::fad1:11ff:fe3d:a61f  prefixlen 64  scopeid 0x20<link>

        ether f8:d1:11:3d:a6:1f  txqueuelen 1000  (Ethernet)

        RX packets 352321  bytes 377585757 (360.0 MiB)

        RX errors 0  dropped 0  overruns 0  frame 0

        TX packets 233440  bytes 20712301 (19.7 MiB)

        TX errors 0  dropped 0 overruns 0  carrier 0  collisions 0
```

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## eyoung100

Try Vendor/Ethernet/Bluetooth MAC Address Lookup and Search

Example:

dummy0: No match

enp3s0: 

Prefix	Vendor

08606E	ASUSTek COMPUTER INC.

This is Indeed the Ethernet on Your motherboard.

wlp5s0:

Prefix	Vendor

F8D111	TP-LINK TECHNOLOGIES CO., LTD.

tun/tap is used for VPN

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## Hu

If the system worked before, and you do not know why you have the new interfaces, you probably do not need them.  You can remove support for dummy0, gre0, sit0, and gretap0.  You might or might not need tun10.

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## krax

the problem is that i do not know what is the kernel option CONFIG_??? in the kernel related to each interface. if i knew i would remove them from kernel

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## therijn

I expect this is not just your kernel but also due to UDEV. You should check the news article "Upgrading udev to version >=200". In short, if you create the file /etc/udev/rules.d/80-net-name-slot.rules and reboot enp3s0 might be eth0 again.

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