Softphone connect issue on GP agent 5.2.8 version when primary DNS is unreachable in GP setting

[Deepak25]

The endpoint having GP client version 5.2.8, is having an issue to connect to Secondary DNS Server for SIP traffic only. The issue is occurring on 5.2.8 when the primary DNS is not reachable.

• WFH users connected to VPN gateways, were having primary DNS DC1 and secondary DNS DC2 in VPN setting.
• Due to Planned activity Primary DNS DC1 server was shut down.
• DNS resolution traffic was successfully working for all the applications (internal and internet ) except genesys softphone SIP traffic by DC2.
• To mitigate the impact, Primary server DC1 started and issue got resolved.
• While doing detailed analysis it has been observed that the endpoint having GP client version 5.2.8, is having an issue to connect to Secondary DNS DC2 Server for SIP traffic only.
• The issue is occurring on 5.2.8 when the primary DNS is not reachable. Same scenario works fine on 5.1.8
• Also when we change the sequence of DNS servers in GP setting i.e. DC2 as primary which is active and DC1 as secondary which is shutdown , then we are able to login the application and can see SIP session on firewall from client machine. Means no issue in DC2

Anyone faced this kind of issue in 5.2.8 ?

[Daniel_Myers]

We updated clients from 5.1.3 to 5.2.12. Our Softphone application is the only thing that stopped working after the upgrade. There are DNS errors in the application logs too. Failing back to 5.1.3 fixes the issue. I do not manage our DNS servers, but we have two configured for the VPN clients.