Same IP under Gateways but not under Interfaces




  • Hoping this is just a simple bug and not an indicator of a possible larger issues somewhere?

    Under the Gateway tab it shows incorrect IP addresses.

    The correct addresses are listed under the Interface tab however.

    Is this just a bug?  Or could it be that I possibly have a corrupted configuration file?  Any insight would be appreciated.



  • What do you mean incorrect? It shows the gateway IPs in the gateways widget, which aren't the same as the interface IPs.



  • That is why I posted the image.  Clearly under WAN1 and WAN2 are showing identical IP addresses under gateway.  Each gateway has its own interface…  I blocked parts of my IP adress for obvious reasons, however, under gateways its saying both WAN1 and WAN2 have the same IP.



  • Having two different interfaces doesn't necessarily mean you have two different gateways. That's up to what the ISP assigns. Both your cable modems are on the same large broadcast domain, and are being assigned the same gateway IP by TWC. It's correct.

    That is a problem because you can only have one ARP table entry for a given IP, hence multi-WAN requires each WAN have a unique gateway IP. So maybe put one of the modems in NAT instead of bridge mode, so you have two different gateway IPs. You won't be able to use both those as-is, but there is nothing wrong with the gateway IPs being displayed.



  • They are not in bridge mode.

    Ok, I didn't realize it is showing the Gateway IPv4 address of the ISP.  I guess I was not exactly looking at this properly.  Now I need to re-evaluate what I thought I knew about my setup!



  • Hmmm… so why is the Gateway IP that is being assigned to my second modem the actual IP of my first modem?  That makes no sense and seems like an issue with my ISP.  So in other words, on my first modem the Gateway IP is the same as it's IP address... Does that seem right?

    WOW!  I need glasses!  And more patience before posting. lol

    Ok, So I am trying to fully understand what you are telling me in your previous post.  So you mean I only want one of the modems to do NAT?



  • @cmb:

    Having two different interfaces doesn't necessarily mean you have two different gateways. That's up to what the ISP assigns. Both your cable modems are on the same large broadcast domain, and are being assigned the same gateway IP by TWC. It's correct.

    That is a problem because you can only have one ARP table entry for a given IP, hence multi-WAN requires each WAN have a unique gateway IP. So maybe put one of the modems in NAT instead of bridge mode, so you have two different gateway IPs. You won't be able to use both those as-is, but there is nothing wrong with the gateway IPs being displayed.

    So I think I understand what you are getting at but I don't see how to put one in NAT or Bridged mode…



  • How to do so varies depends on the modem, but generally they all have an option to be put into a NAT mode, where the modem will obtain your public IP, and have a private IP subnet internally. Look up the manual for your modem.


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