Configure laptop to auto-run on separate connections

Friend has laptop configured to run on home network (no idea if wired or wireless).

He wants to use it at work too (of which I am IT admin). It's not a security issue, as the laptop is not used for business-critical things, rather than surfing for supplier prices and e-mails.

I assume I just add another Internet connection, but is there a way to get the laptop to ID the connection and auto-neg the IP settings? DHCP is not in use in either.

I suppose that the odds are that it has Windows.
Windows used to have a facility for a secondary set of IP stuff (which I never found too helpful), bu I don't know if that still exists.
Linux ? I have no idea.

The secondary IP was only really useful as a backup to DHCP in case the server failed.

I think the question on this one is why DHCP is not being used as that would be the easiest way to do this. I can't think of a way to automatically switch IP addresses - you could do it with a manual switch over by creating a reg file with the appropriate entries or possibly using 3rd party tools.

If the laptop is running wifi, then there should be no issue. I use a Macbook pro at work and at home and there's no setting up to do. Having said that it connects via a VPN, not sure if that makes a difference, as we need a secure connection.

Why are you not using DHCP?

I would just configure the wired connection with the settings for work, and ask him to use wireless at home.

To all:

It's windows, yes.

DHCP is not in use. Suffice it to say, while it might be a good idea, it's not in use.

No idea about wifi at home, but it is wired at the office (it probably could be wifi, but there would still be the separate network issues without DHCP).

I did consider a simple batch file, but automatic detection to trigger a batch file is less simple. So it would be a manual process.

I might look at this - http://www.eusing.com/ipswitch/free_ip_switcher.htm

It too might be a manual process, but will have a look and see.

Edited by camieabz (Thu 15-Oct-15 13:23:49)

I fail to understand why you don't use wifi in the office and DHCP. It works, it's not that difficult, and it allows remote workers (like me) to just come in and get going. Why make life difficult?

Fixed IP addresses were the only way before but they have no place now in a modern office environment.

If there is DHCP at home but not in the office, then using the Alternate Configuration functionality is the way to do it.
http://www.addictivetips.com/windows-tips/how-to-con...

DHCP is not in use at home (as far as I know). I can't change the home settings. I would love it to be DHCP.

Just to clarify, DHCP is in use in the office (apologies if my OP confused that point).

Until I can get my hands on the laptop, I can't know exactly what to expect, but I was planning ahead with the possibility of static IP at home, and wanted to thrash out an IP switching solution.

If DHCP is in use at the office but not at home, configure automatic as the primary address (i.e. DHCP) and the home details as the secondary address. DHCP will be attempted at home, will fail, then the secondary details should be used.

In reply to a post by David_W:

DHCP will be attempted at home, will fail, then the secondary details should be used.

don't forget that you have to wait for the dhcp requests/ no reply first so may take ages (a couple of minutes) before it finishes starting.

Ah. Ta.

In reply to a post by ggremlin:

In reply to a post by David_W:

DHCP will be attempted at home, will fail, then the secondary details should be used.

don't forget that you have to wait for the dhcp requests/ no reply first so may take ages (a couple of minutes) before it finishes starting.

Unfortunately so.

In my opinion (and, I believe, the original poster), it's a pretty bogus decision not to use autoconfiguration with portable devices. If a static IP is desired on the home network, the user can almost certainly configure a static IP to MAC mapping on the DHCP server - even cheap consumer routers support this.


It might be that the home network runs without a DHCP server in an attempt at preventing unauthorised devices from using the network. One way around this is to run a DHCP server that only responds to certain MAC addresses, though this will likely be beyond the capabilities of the DHCP servers in most consumer equipment.


If security is really a concern, a better solution is to use a switch with MAC filtering. Better still is to use 802.1x port based security. A cheap 8 port managed switch and, if you want 802.1x, a Beaglebone Black running FreeRADIUS 3 will do the job admirably. A ZyXEL GS1900-8HP is less than £90, and has the advantage of 802.3at Power over Ethernet support on each port. I'm not sure the non-PoE version is still available, but if you look around you can probably get an 8 port managed switch new from another manufacturer for around £50.

If you deploy a FreeRADIUS server, you can move from WPA2 Personal (pre-shared key) to WPA2 Enterprise (using EAP against a RADIUS server) assuming you have WPA2 Enterprise support in the access point.