After upgrading to hub 7.70 tunnel connections may appear unstable

Document ID : KB000034323
Last Modified Date : 14/02/2018
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NOTE: hub 7.71 has been released which contains a fix for this issue as of 4/3/2015.

In some environments, after upgrading to hub 7.70, tunnel connections may appear unstable. ?Downgrading to 7.63 appears to restore stability.

First, the following article should be checked -- the hub upgrade may have reset some of the settings if you have previously changed them:

Additionally,?there has been a change in the way internal tunnel ports are allocated, which could have implications in highly "locked down" or secured environments.

In such environments, it may be that a customer has internal firewalls which block communication even between hubs and/or robots except for the normal Nimsoft port range, e.g. 48000+ ?so that the robots and hubs can only communicate with each other on that specific range.

In hub 7.63 and prior, a tunnel client/server connection would allocate internal ports to use for the tunnel connections which would fall into the 48xxx range unless the "First Tunnel Port" option was explicitly set to "ignore first probe port from controller" and a specific tunnel port designated.?

In 7.70, the behavior has changed -- now, if a specific First Tunnel Port is not explicitly set, the internal ports used for the tunnel connections will be on randomly allocated ports instead of automatically falling into the 48xxx range. ??

This change may cause tunnel connections or communication across tunnels to appear to fail, sometimes intermittently. ?

To resolve this you should set "Ignore first probe port from controller" in the hub GUI under Tunnel->Advanced and set the first tunnel port to 48004.?

screenshot of hub advanced tunnel settings