ISA App Logs "Server poll timeout"
This Article highlights the steps to be taken in case the ISA App on Windows is unable to connect and the message seen in the ISA App Logs is "Server poll timeout"
Issue
"Server poll timeout, restarting" is a message that indicates that the OpenVPN client has encountered a timeout while trying to poll the server for a response. OpenVPN uses a keepalive mechanism to ensure that the VPN connection is still active. The client sends a message to the server, called a "poll", at regular intervals. The server is expected to respond to these polls within a certain time period. If the server does not respond within the time period, the client assumes that the connection has been lost and takes appropriate action, such as restarting the connection.
The most common reason for such a situation to arise is a network block. The ISA App would be unable to connect as expected if it is unable to communicate with the InstaSafe Controllers, and the ISA App Log File would display the message as shown below:
UDPv4 link remote: [AF_INET]<103.220.168.102><1234>
Server poll timeout, restarting
SIGUSR1[soft,server_poll] received, process restarting
In the above example, the ISA App is attempting to connect to the InstaSafe Controller with Public IP 103.220.168.102 on UDP Port 1234, and is unable to do so indicated by the message 'Server poll timeout'.
The typical causes for the network block and their corresponding solutions are mentioned below:
- Block from the ISP: Some ISPs may arbitrarily block traffic towards the InstaSafe Controllers. Making use of an alternate available internet connection (from a different provider) would help
- Block from the Network Firewall: When connecting from a Corporate Network, certain internet traffic might be blocked by the Firewall or a similar network device. The IT Team would need to allow the outbound InstaSafe Traffic, in order for the ISA App to connect
- Block from an End-point Protection Software: Some tools installed on the end-user machines with a Network Protection component (Firewall, Traffic Monitoring and Filtering, etc.) might also drop the traffic initiated by the ISA App. Appropriate steps might need to be taken to allow the traffic and possibly even add the ISA App to the Exclusion List
Besides the above mentioned reasons, the message "Server poll timeout" would be noticed if:
- The InstaSafe Controller(s) hosted for the organization are in a 'Stopped' state, or the underlying Server is offline
- The InstaSafe Controller(s) hosted for the organization are unable to accept inbound traffic (connection requests from ISA Apps) due to a change in the network configuration
In case the issue persists after following the above mentioned steps, please contact your organization's IT Team.
If you are an Admin of the organization's ISA Account and need assistance, contact
InstaSafe Support.