Hi all,
I do not understand this either. We saw the same issue during the recent Skyline-Online: Session 1. Several of the participants were unable to connect to Prosit. It is most likely a network issue between you and the Prosit server (proteomicsdb.org). Notice that we use port 8500 in connecting to the server. Perhaps for some reason port 8500 is no allowed somewhere between your computer and proteomicsdb.org, e.g. your computer firewall or your institution firewall.
So, while the "ping" that Nick suggests is an okay place to start, because proteomicsdb.org does respond to ping, it doesn't really tell you if you can get to port 8500 from your computer. A better option can be found on this page (had to Google it myself):
https://www.libe.net/en-ping-port
With it, I was able to check 8500 (and also 80 for normal HTTP and 443 for normal HTTPS), all 3 are open to my comptuer on proteomicsdb.org, but port 1000 is not:
PS C:\Users\brendanx> Test-NetConnection -computername proteomicsdb.org -port 8500
ComputerName : proteomicsdb.org
RemoteAddress : 131.159.152.5
RemotePort : 8500
InterfaceAlias : Ethernet
SourceAddress : 128.208.10.70
TcpTestSucceeded : True
PS C:\Users\brendanx> Test-NetConnection -computername proteomicsdb.org -port 80
ComputerName : proteomicsdb.org
RemoteAddress : 131.159.152.5
RemotePort : 80
InterfaceAlias : Ethernet
SourceAddress : 128.208.10.70
TcpTestSucceeded : True
PS C:\Users\brendanx> Test-NetConnection -computername proteomicsdb.org -port 443
ComputerName : proteomicsdb.org
RemoteAddress : 131.159.152.5
RemotePort : 443
InterfaceAlias : Ethernet
SourceAddress : 128.208.10.70
TcpTestSucceeded : True
PS C:\Users\brendanx> Test-NetConnection -computername proteomicsdb.org -port 1000
WARNING: TCP connect to (131.159.152.5 : 1000) failed
ComputerName : proteomicsdb.org
RemoteAddress : 131.159.152.5
RemotePort : 1000
InterfaceAlias : Ethernet
SourceAddress : 128.208.10.70
PingSucceeded : True
PingReplyDetails (RTT) : 167 ms
TcpTestSucceeded : False
Try this on your computer along with ping. I would be surprised if ping or ports 80 or 443 are blocked to you, but 8500 may be, and that would be a problem for Skyline trying to communicate with Prosit on proteomicsdb.org.
Armed with this information, you should also be able to approach an IT professional and clearly explain what you want (i.e. access to port 8500 on the proteomicsdb.org server). Hopefully, that would be enough for them to help expose that port on whatever is currently blocking it.
If you figure out what is blocking it and why, we would be interested in understanding that. It might enable us to approach the Prosit team and request a change that is more likely to work for more Skyline users.
Thanks for your post and the time you have taken to investigate this issue on your computer.
--Brendan