LAN overlap problem between work VPN and home LAN



  • I am trying to figure out the best way to solve a LAN overlap issue. My case involves connecting to a network at my office via VPN. The LAN at work is on the same subnet as I am on at home... 192.168.1.xxx... and that is causing issues, mainly the 'not working at all' issue.

    The VPN connection is using L2TP. This is something which is configured by my employer's IT company. My options are make it work with your home network or, no... that is my only option.

    What can I do to put (at least) one PC located on my home network onto a 'non-conflicting' subnet? I don't care if I have to manually go and 'flip a switch' in the Pf gui (or some similiar routine) in order to route the home PC to something that will work with my work.

    Thanks!



  • @cobrahead why not just change the whole LAN subnet to anything else in the 192.168.xxx.xxx or 10.xxx.xxx.xxx or even the 172.16-31.xxx.xxx range.



  • @napsterbater said in LAN overlap problem between work VPN and home LAN:

    @cobrahead why not just change the whole LAN subnet to anything else in the 192.168.xxx.xxx or 10.xxx.xxx.xxx or even the 172.16-31.xxx.xxx range.

    That would work. I just imagined it would be a cluster to do. How would I go about changing the entire range on an active LAN?



  • @cobrahead said in LAN overlap problem between work VPN and home LAN:

    How would I go about changing the entire range on an active LAN?

    Change the LAN address and DHCP addresses.

    BTW, I ran into the same problem years ago, when I did a lot of travelling for work. I'd find myself in a hotel that conflicted with my home network. I moved my network to the 172.16.x.y range, as I have never seen anything in that range used elsewhere.



  • @jknott said in LAN overlap problem between work VPN and home LAN:

    @cobrahead said in LAN overlap problem between work VPN and home LAN:

    How would I go about changing the entire range on an active LAN?

    Change the LAN address and DHCP addresses.

    The easiest way to do this, in my opinion, because I've been in the same situation as you guys, is to change the LAN IP address range and DHCP addresses from a console or SSH connection. Don't try to do it thru the webgui on the LAN interface, it will flip out as soon as the IP address range is updated/changed. Or, if you've got a management interface setup, update the LAN settings thru here.

    Like @JKnott says, the 172.16.0.0/12 range is a good one. I don't bump into that one too many times, out in the wild, myself.

    Jeff



  • @jknott said in [LAN overlap problem between work VPN and home LAN]

    Change the LAN address and DHCP addresses.

    BTW, I ran into the same problem years ago, when I did a lot of travelling for work. I'd find myself in a hotel that conflicted with my home network. I moved my network to the 172.16.x.y range, as I have never seen anything in that range used elsewhere.

    @akuma1x said in [LAN overlap problem between work VPN and home LAN]

    The easiest way to do this, in my opinion, because I've been in the same situation as you guys, is to change the LAN IP address range and DHCP addresses from a console or SSH connection. Don't try to do it thru the webgui on the LAN interface, it will flip out as soon as the IP address range is updated/changed. Or, if you've got a management interface setup, update the LAN settings thru here.

    Like @JKnott says, the 172.16.0.0/12 range is a good one. I don't bump into that one too many times, out in the wild, myself.

    I tried changing it from the console, but it flips out anyways. Should I use 172.16.0.0/12 as the LAN IP with a range of say, 1.1 - 1.254? I got the 172.16.x.x going enough that I could log into the web gui... and it showed the WAN as up and running, but I could not access the internet. I tried rebooting the Pf box and my PC ... I did not reboot my modem. Is there something I am missing?

    Thanks!



  • @cobrahead

    What I did on mine was set LAN IPv4 to a static 172.16.0.1, subnet range to a /24. A range of /12 will give you over a million IP addresses to use internally on your LAN. That's probably too many, in this scenario. LOL

    Then set the DHCP server on LAN starting at 172.16.0.2 to anything less than or equal to 172.16.0.254

    You should be able to config all those settings thru the console or SSH, like I said. And, then, it wouldn't hurt to reboot all your gear, the modem too.

    Jeff



  • @akuma1x said in LAN overlap problem between work VPN and home LAN:

    @cobrahead

    What I did on mine was set LAN IPv4 to 172.16.0.1, subnet range to a /24. A range of /12 will give you over a million IP addresses to use internally on your LAN. That's probably too many, in this scenario. LOL

    Then set the DHCP server on LAN starting at 172.16.0.2 to anything less than or equal to 172.16.0.254

    You should be able to config all those settings thru the console or SSH, like I said. And, then, it wouldn't hurt to reboot all your gear, the modem too.

    Jeff

    Will do, thanks for the pointers!



  • @akuma1x said in [LAN overlap problem between work VPN and home LAN]

    Jeff

    That worked! I had one issue that involved changing some rules under the firewall section. Thanks again!