Same IP, multiple interfaces, how?

[exabyte]

My Gentoo broke. It seems that after some update I did in the last few months, it refuses to put the same IP on an interface, if another interface has it already. One of the interfaces is ethernet with netplug and dhcp, the other is a wireless LAN with wpa_supplicant and static configuration for the AP I'm connecting to. How to fix this misfeature? It's driving me fucking insane, I can no longer switch between wireless and cable by connecting/disconnecting my cable.

[VinzC]

Assinging the same IP address to two distinct interfaces is a mistake. I wonder why you could before but it's something that must be avoided.

Gentoo baselayout is flexible enough to allow you different settings according to various situations. You can have a fixed IP when connecting to your AP and yet a dynamic IP assigned from DHCP through Ethernet cable. Example:

[exabyte]

Thank for the reply.

Assigning the same IP to two distinct interfaces might be a mistake in theory (though I doubt it), but can be very useful and there are configurations that can't be achieved without using so. The cases where I've been using it include two interfaces to the same physical network, like I'm trying to do now, proxy arp configurations, especially those between hunreds of interfaces, etc.

I want to achieve this - put my cable, my packets automagically begin going through the cable, pull my cable, my packets automagically begin going through my wireless. It was exactly like this (with absolutely no delay on connecting the a cable, and a minor on disconnecting it, and no connections dropped) until I got bitten by this change, which apparently blocks the interfaces from starting.

The change must have happened some time during the last year, as I didn't have any real use for this, until I recabled my whole appartment now. Now I have to type my password and fire up a shell everytime I need to change from wireless to cable and vica versa, plus the delay is so big, that some connections get dropped and other get stalled for seconds to minutes. And I've been used to the fact that everything in my Gentoo happened absolutely automatically with no intervention on my part for absolutely *anything*, so I'm very frustrated by this.

The example you gave is exactly how I configured my wireless. The LAN card is using DHCP, plus several static gateway configurations. The DHCP gives me the same IP I have on the LAN card, and I want both to go up in this configuration, with no stupid refusals.

I'm still not using openrc on this machine, though I'm currently upgrading to it.

[VinzC]

You might want to try bonding -- although I've never done that. Bridging between wifi and ethernet would allow you to do what you want but bridging with WiFi is hazardous because of firmware, basically. So bonding is the only way I'm thinking of ATM: two NICs --> one IP.
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[exabyte]

I don't think that bonding is supported by my network equipment, if it is supported at all in such configuration. And bonding is certainly not what I want. By the way, I switch from wireless to cable mainly because of the delay. PulseAudio doesn't work in my wireless network because of the delays, you see.

However, I think I found the source of my problem, as it was two mistakes on my part. It's arping that was breaking my wireless, which gets fixed by this:

[VinzC]

dhcpcd has been upgraded to version 4 to fit RFC4702 about DHCP servers -- DNS encoded hostnames deprecates text encoding. You may safely downgrade to version 3*.
_________________
Gentoo addict: tomorrow I quit, I promise!... Just one more emerge...
1739!