Re: control of order of inet devices

On Tue, Apr 16, 2013 at 03:56:21PM +0200, Willy Offermans wrote:
> Dear FreeBSD friends,
> 
> How can I control the order of the network devices in FreeBSD.
> 
> For example, the command ifconfig lists the network devices:
> 
> pcn0: flags=8802<BROADCAST,SIMPLEX,MULTICAST> metric 0 mtu 1500
>         options=80000<LINKSTATE>
>         ether 00:0c:46:ea:2b:32
>         nd6 options=29<PERFORMNUD,IFDISABLED,AUTO_LINKLOCAL>
>         media: Ethernet 100baseFX
>         status: no carrier
> rl0: flags=8843<UP,BROADCAST,RUNNING,SIMPLEX,MULTICAST> metric 0 mtu 1500
>         options=2008<VLAN_MTU,WOL_MAGIC>
>         ether 00:11:6b:99:7c:5a
>         inet XXX.XXX.24.4 netmask 0xffffff80 broadcast 137.226.24.127
>         inet6 fe80::211:6bff:fe99:7c5a%rl0 prefixlen 64 scopeid 0x4 
>         nd6 options=29<PERFORMNUD,IFDISABLED,AUTO_LINKLOCAL>
>         media: Ethernet autoselect (100baseTX <full-duplex>)
>         status: active
> nfe0: flags=8802<BROADCAST,SIMPLEX,MULTICAST> metric 0 mtu 1500
>         options=82008<VLAN_MTU,WOL_MAGIC,LINKSTATE>
>         ether 00:1b:fc:df:a1:33
>         nd6 options=29<PERFORMNUD,IFDISABLED,AUTO_LINKLOCAL>
>         media: Ethernet autoselect (none)
>         status: no carrier
> plip0: flags=8810<POINTOPOINT,SIMPLEX,MULTICAST> metric 0 mtu 1500
>         nd6 options=29<PERFORMNUD,IFDISABLED,AUTO_LINKLOCAL>
> lo0: flags=8049<UP,LOOPBACK,RUNNING,MULTICAST> metric 0 mtu 16384
>         options=600003<RXCSUM,TXCSUM,RXCSUM_IPV6,TXCSUM_IPV6>
>         inet6 ::1 prefixlen 128 
>         inet6 fe80::1%lo0 prefixlen 64 scopeid 0x7 
>         inet 127.0.0.1 netmask 0xff000000 
>         nd6 options=21<PERFORMNUD,AUTO_LINKLOCAL>
> tap0: flags=8843<UP,BROADCAST,RUNNING,SIMPLEX,MULTICAST> metric 0 mtu 1500
>         options=80000<LINKSTATE>
>         ether 00:22:19:10:8d:bb
>         inet XXX.XXX.24.19 netmask 0xffffffff broadcast 137.226.24.19
>         inet6 fe80::2bd:83ff:fe68:7200%tap0 prefixlen 64 scopeid 0x8 
>         nd6 options=21<PERFORMNUD,AUTO_LINKLOCAL>
>         media: Ethernet autoselect
>         status: no carrier
> 
> pcn0 being first. However, I would like tap0 being first and of course
> without any output ordering trick.

The order is dictated by the order the drivers are probed by the kernel.
When the devices are created they are added to a linked list.  There is
no practical way to control the order and it has little or no effect.

-- Brooks