Switch eth0 and eth1, how?

[JD]

On 10/19/2012 04:48 PM, Frantisek Hanzlik wrote:
> Fernando Cassia wrote:
>> In my server I have eth0 and eth1 (previously were em16, em17, but I
>> hated it so I changed to the traditional approach).
>>
>> Each NIC port is connected to a different ISP. However, more often
>> than not while moving things around I get the cables reversed so ETH0
>> goes to ISP2 and ETH0 goes to ISP2, or vice versa, ie the cables are
>> interchanged.
>>
>> So... is there a way, in such situation, to manually (say, from a bash
>> script) bring down both eth ports, and re-arrange those? (so that eth1
>> becomes eth0), and do so without a reboot?.
>>
>> I´d like to make eth0 and eth1 consistent regardless of mixed cabling
>> so every time I bring down eth0 I know what isp I´m bringing down.
>> What IP each port is connected to I can figure out via a query to
>> www.whatismyip.com, but the question remains if it´s possible to
>> change the naming of two ethernet ports without a reboot.
>>
>> What would be the best way? ethtool?
>>
>> TIA
>> FC
> IMO one possibility is deactivate interfaces, by rmmod unload its drivers,
> change /etc/udev/rules.d/NN-net.rules and modprobe/insmod drivers again
> (and then activate network). udev daemon should create network names with
> new ones.
> Another way could be using 'ifrename' utility from 'wireless-tools'
> package: 'ifrename -i OldInterfaceName -n NewInterfaceName'
> (network perhaps should be down too and it seems as ifrename requires
> '/etc/iftab' file (which may be empty, 'touch /etc/iftab'))
>
> FH
Thanx a million. THAT WORKS!!