Split DNS and Failover

Discussion in '3CX Phone System - General' started by kencomp, Mar 4, 2016.

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  1. kencomp

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    Hi

    I'm just testing the auto failover in 3cx version 14 SP3. I've set it all up and it detects when I disable the network card on my main machine and starts the services on the backup. However, when I go on my smart phone app. It was auto provisioned with external fqdn but the local pbx address is the ip address of the server. So when failover occurs, the new machine is obviously a different ip address so the phones wont connect to it.

    How can I have the auto provision send the local fqdn and not the ip address to the phones? I set the split DNS option when I installed it.

    Thanks
     
  2. ian.watts

    ian.watts Active Member

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    Chasing what is being sent on my system.. here's what I am seeing:

    The .3cxconfig file I welcomed myself with on email has a ProvLinkExternal URL and MyPhoneServerPublicAddr URL as well.

    So.. if I fetch the ProvLinkExternal XML (the provisioning file).. I see that PBXPublicAddr is FQDN.
    Nowhere am I seeing an IP address on my files, nor my phone's account settings.

    When you use split DNS, there should be no "External" or "Local" FQDN in play at all.. just one.
    The active/passive configs use addresses to monitor and switch, sure, but it still sounds like something in your config is provisioning by address instead of name.

    Split DNS is a prereq for failover, mainly so that DNS can update the host address in an event. By itself, though, Split DNS should remove "internal/local" and "external" FQDNs, by nature of what Split DNS is. So.. that's not it.. but your config is.. somewhere. :)
     
  3. kencomp

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    See in the provisioning template for ours, it shows the local IP address of the server. Why would it not be giving out our domain name?

    When installing 3cx, selecting single FQDN is the option I need to select right? This was the one I used so confused as to why its provisioning local with an IP address and not the FQDN. Is there any way to change this now after the install?
     
  4. Bunce

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    I think there's been a bug with the FQDN variable since back in V11.

    We implemented our own failover approach using VM replication back then given the lack of any inbuilt HA capability, and came across the same thing.

    Irrespective of which variable you use in the template to try and represent the 3CX server,'s DNS/FQDN name it would *always* use the IP address.

    We ended up hard-coding the full FQDN in the template so that the DNS name was provided to the handsets. This then allowed us to utilise DNS for failing over to the secondary 3CX server by updating the DNS IP.

    We did log the bug but nothing came of it.
     
  5. mortenjorge

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    Hi,

    It seems like this "bug" still happends.

    I've installed our 3cx in Split dns mode. - I've selected our fqdn in Phone provisioning (3CX CLIENT) instead of our local ip.

    I've deleted my extension on my softphone, and regenerated a new welcome mail.

    "on office" is still our local IP.

    Does any of you get the 3CX failover solution to work?
     
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  6. komnet

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    Hi,

    mortenjorge, you are totally right.

    In v15, extension properties are permit us to select what interface will be used. However, the config files generated with pbx local IP even if local FQDN was selected as interface.

    To workaround, we manually changed PBXLocalAddr parameter in provisioning file sended via email by 3CX, before applying to 3CX Phone.Then you have to uncheck "Reprovision on startup" option on 3CX Phone's account properties. After then 3CX Phone will use local FQDN instead of local IP.

    Then wait 3CX developers to fix that bug at the next SP.

    Komnet
    Platinum Partner
    Istanbul-Turkey
     
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