Routing issue on 10.

  • Hello,

    I've set up open vpn. Everything is working perfectly except for one issue. I am using 10.x for my ip address space on the router, and if the person's originating network is also 10.x he can connect, but cannot route traffic properly. Any suggestions for what this might be? Is this a client side issue or something that needs to be set up on the server?


  • Rebel Alliance Developer Netgate

    If the client's home/remote network overlaps, it will cause problems no matter which net you're in (10/8, 192.168/16, or 172.16/12)

    It's an issue on the client side because the client will believe that the IPs are local to him and thus his workstation will never attempt to use the VPN for those IPs.

  • I see, so what needs to be done on the client to get this to work?

  • Rebel Alliance Developer Netgate

    They need to not be in a conflicting network. There isn't anything else you can really do.

    It's either that, or renumber the server side so you're in something else that doesn't conflict.

    One side or the other would need to change IPs. Avoiding overlaps is fairly difficult in this day and age, especially with people who roam all over the planet to various hotels, airports, coffee shops, etc…

  • LAYER 8 Global Moderator

    So when you say they use 10.x you mean they are using /8 for their mask??  And you are using same ?

    As already stated you can not have overlapping networks on both sides of a vpn without issues.

    But for example at work we use a 10.x.x.x/24 network – something like I believe, not sure off the top of my head for desktop segment at my location.

    So if your using say and they were using you would be fine..  But if they are using a /8 mask or even /16 then yeah its possible your 10.x.x.x/24 could overlap with that.

    Need to change 1 side of the network.  And I would for sure never be using a /8 or /16 mask..  How many hosts do you have??

  • His network is out of my control unfortunately, but he was using 10/24 and we are using 10/13. We need ours for a variety of services including dns that he'd need connected to vpn.

  • LAYER 8 Global Moderator

    10/24 what?? your missing some info there 10.x.x/24?

    And then your 10/13 – so missing some info 10.x/13  -- if you told me 10/13 I would assume your on an address that falls in the 1st subnet on that so -

    So if you tell me 10/24 without any other info I assume 10.0.0/24 -- so you would overlap..

    Now if he is on on one side and your on 10.8/13 on the other then your network would be - and you would not be overlapping.

    So your using 10.x/13 -- so you have like 524K+ hosts all on the same network?  A /13 is a LARGE segment.. I find it hard to believe you need such a large network other than bad design.

  • Pretty simple deal, just have to make sure your LAN segments do not overlap, but we need more info.  10.x is not enough information, we need all the octets and the network mask.

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