default virtual network interface

Question

I got a single ethernet connection to a network but with multiple ips.
Because of this, I am using virtual network interfaces like this:

auto intern
iface intern inet static
        address ...
        netmask ...
        gateway ...

auto intern:1
iface intern:1 inet static
        address ...
        netmask ...
        gateway ...

I need to configure which IP should be used by default for outgoing traffic.

How can I do that?

score 0 · Answer 1 · answered Sep 24 '12 at 06:41

0

You need to use the option -b src.ip.addr.ess. For other tools, you need to at the manual to check for the right option. Also, telnet and ssh use the same option -b.

answered Sep 24 '12 at 06:41

Khaled

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I am not looking for all those interface options, but for a way I can set the DEFAULT for all network-connected tools. – Zulakis Sep 24 '12 at 07:12
By default, each program/tool will use the "primary" interface address. I am not aware of a way to change this behavior globally unless you change this primary address. – Khaled Sep 24 '12 at 07:29
How can I set the primary interface? What other effects could changing it have? – Zulakis Sep 24 '12 at 08:18
the primary interface is the first interface it finds on the subnet, otherwise its the first interface it finds which is on the subnet where the gateway is. – Flash Sep 24 '12 at 09:38
"It finds"... There must be a way on how to set this. – Zulakis Sep 24 '12 at 10:24

score 0 · Answer 2 · answered Sep 24 '12 at 18:05

0

I need to configure which IP should be used by default for outgoing traffic.

Make it the first one listed in /etc/network/interfaces for that interface.

Example:

iface intern inet static
    address 198.51.100.30 # This one is it

answered Sep 24 '12 at 18:05

Michael Hampton

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This does not work. The second one (out of three) is getting used. – Zulakis Sep 24 '12 at 18:11
OK, then please edit your question to provide a more realistic view of what your `interfaces` file looks like. – Michael Hampton Sep 24 '12 at 18:12
It it not that different, just `intern, intern:1 and intern:2` - `intern:1` is getting used – Zulakis Sep 24 '12 at 18:13

score 0 · Accepted Answer · answered Oct 02 '12 at 10:55

0

It looks like the first sub-interface (intern:1) of the first interfac eis getting used as default device. It's a little bit weird that not just the primary interface (intern) is getting used.

If anyone has a fix for this, feel free to post.

answered Oct 02 '12 at 10:55

Zulakis

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default virtual network interface

3 Answers3