Dear all experts,
I am lost in this issue that recently happened on my company:
The staffs in my company are using Notes client, we are connected to our Domino server locally and we access few database that are located in 2 remote servers sitting side-by-side (GCM02 and GCM03).
Since yesterday, we cannot access only GCM02, Notes just freeze and hang after we choose any databases in GCM02.
I am able to ping the GCM02 via cmd prompt, trace GCM02 via Notes client Trace function and telnet GCM02.
After some exhaustive observation and diagnosis, we managed to fix this issue by installing a third party software, 'Cisco Systems VPN Client 5.0.07.0410', without any configuration after installation .
I conlude the following:
1) Laptop can only access GCM02 server after reinstall the VPN client
2) Laptop can still access other Domino servers in the network (in particularly GCM03)
3) Laptop cannot access GCM02 regardless of the version of Lotus Notes being used
4) Using different IDs to access GCM02 after installation  had no issues accessing
5) Reinstalling Lotus Notes will not solve this issue
On problematic laptop (before installing VPN), Wireshark showed that client received ACK packets twice, but such reading doesn't show on non issue laptop:
Please let me know if you need these as I can't attach them here:
> Both PSR recordings on before and after installing VPN client.
> Both registry files that I exported before and after installing VPN client.
> Cisco VPN installer that I used as workaround
I hope to hear good news from fellow experts here, thanks and have a nice day.