can't add more XEN interfaces


I get this error:

Failed to save network interface : SIOCGIFADDR: Cannot assign requested address SIOCSIFBROADCAST: Cannot assign requested address SIOCSIFBRDADDR: Cannot assign requested address SIOCSIFFLAGS: Cannot assign requested address

when I try and add more than 2 XEN interfaces to a VPS. What could cause this, and how do I debug / fix it?



Which page in Cloudmin are you getting this error message on?

Also, are you adding an extra interface to the Xen guest, or the Xen host?

Well, I goto a XEN instance, then click on System Configuration > Network Interfaces.

What's interesting though, when I did it again, the IP went through to the instance without the error, and then I got the error again while adding the 3rd IP.

Was it a real (eth2) or virtual (eth0:2) interface that you were adding?

I think it was virtual, since I didn't even know about the XEN bridges, until now :)

Was the IP of the new interface on the same network as the main IP?

That's odd, I don't see this on my test systems.

Which Linux distribution and version is the Xen guest running?

I see, that since I upgraded to CloudMin 4.0, this option is totally gone. How do I add new IP's to existing (and new) XEN VPS's now?

What state does cloudmin show for the system where this doesn't appear?

Hi Jamie,

Sorry, I should have said this. There's no "System Configuration" anymore. For any XEN instance which is running.

The current status is "Alive". I found the SSH login thing to be a bit annoying and since no-one can tell me what it does, I disabled it in CloudMin.

BUT, I see now when I change it back to SSH login, the menu is available. Again, how does the login behind this work?

Ok, that is expected .. if you disable SSH logins, Cloudmin cannot login to the Xen instances to do things like listing active network interfaces. In this case, the status will just be 'Alive'.

This mode is really only useful for Xen instances running Windows, or physical systems that you want to monitor but not manage.

Please re-evaluate this process. The SSH logins is causing a lot of problems on our client's VPS. Not only is it a privacy concern, but clients who use ConfigServerFirewall or any other script to notify them of SSH root logins gets an email every 10 minutes saying someone logged in.

So, now the client change their root passwords, we get bounce emails every 10 minutes, and clients get "possible hack attempt" emails. And, then we can't change their IP's in any case.

So if Cloudmin can't SSH in, it can't really manage the IPs on a Xen instance properly. I suppose it could edit the IP in the .cfg file, but that seems dangerous unless the IP on the VPS is changed too - if they don't match, network access could be broken.

It sounds like you should just use the "No SSH login" mode.

Sure, I understand, but the SSH logins cause more overhead, and I don't know if it's worth if for the one-time IP address changes every few months? How about adding it to the xen.cfg file, and then do a SSH login at that time to add it to the VPS as well? i.e. have SSH disabled all the time, but only connect to the host when needed?

I suppose that could be done, but it seems like an odd approach .. normally either the Xen guests can be contacted via SSH all the time, or they cannot.

One other option may be to disallow SSH logins, and when you want to change the IP shut the guest down. Cloudmin will then be able to manage interfaces by mounting the Xen disk image and editing the network config files.

Hi Jamie,

Ok, I see this is going to be a problem either way, so don't worry about it :) It's easier to just tell the client to add the IP's himself and keep it on a spreadsheet or in ipplan like we've been doing up to now.

I can't force a client to give me SSH access, or force him to shutdown just to add an IP. It's a nice feature that Cloudmin can add it without downtime, but the current practice doesn't work for us. It's not supposed to work for everyone, and that's fine as well.