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[Maltsters]

HI

I am running JRiver 24.0.78 and following some security enhancements to my network noticed that when JRiver was playing audio showing the Now Playing or Info views in Theater View, it would download pictures from the internet for about 10-15 minutes and then suddenly stop displaying them.

I have analysed this behavior and believe it to be caused by the JRiver continuing to use the IP address returned from the initial DNS query after the DNS Time To Live value has been exceeded.

In the case of my network any client promiscuously using an IP address, without an associated query is blocked (this enforces DNS Filtering). Following a DNS query, my firewall will allow traffic to the specified IP address until the DNS TTL value is reached and then block further traffic, unless a further DNS query is issued which will reset the clock.

Whilst I know this setup is highly unusual, it is best practice to requery the DNS server for an address update before the TTL expires and not continue to use the IP address the after the TTL has expired.

My observation is the no matter how long I leave JRiver playing, it does not normally perform another DNS query unless I exit and return to Theatre view.

This is probably a Bug or Oversight in the way JRiver uses IP addresses returned from DNS Queries. Can this be added to the bug list and get fixed at some point.

Many thanks

Ian

[Matt]

I'm puzzled by this behavior because Theater View just gets a list of URLs and works through them with our internet reader code.  I would expect that to properly update.

[bob]

This is almost certain to be the windows DNS cache in action...

[Maltsters]

Thanks for the responses, the local DNS server is Linux based rather than Windows and is located on the Router that is doing the traffic management / blocking and so it is designed to operate in this way. If I allow the use of expired IP addresses just for the JRiver machine, it works fine as soon as I block the use of expired IP addresses, it stops working.

Every other machine I have (10 of them) all work fine in that I am not seeing any significant DNS/IP address expiring issues. I do also operate Windows Server DNS but these are secondary to the one running on the router and primarily are used for internal DNS resolution and Active Directory.

I clearly do not know the inner workings of JRiver but am reasonably confident that this is linked to using expired IP addresses for the lookup of images - everything else in JRiver seems to work just fine. It may be that the internet reader code, just queries DNS to get the URL IP address and when it has it, just keeps using it as long as it keep looking for images rather than periodically requery?

[bob]

Windows does address caching independent of your DNS settings.

Edit:
And we do none.