Blocking VPN IP address?


I work for a company (Schweitzer Engineering Laboratories) where all employees must use a VPN while working remotely. The VPN uses the IP address, and we were wondering if perhaps this IP was being blocked by ibibilio?

Thanks in advance!

Tony Kuphaldt (maintainer of the Socratic Instrumentation, Modular Electronics Learning Project, and other open-source learning projects hosted on ibiblio)

Hi @tonykuphaldt, good to hear from you. It’s hard to dig into what exactly happening without more detail. What service are you trying to use, and what error are you getting? We don’t maintain any one global block, but we do have various tools that automatically apply blocks based on behavior to prevent abuse (eg. too many failed SSH logins in a certain time span result in an SSH block), and as part of the university, we are subject to any rules applied globally at the campus border, which might happen for any of several reasons. With that said, I don’t see the IPv4 address you mention in any of the several places I have access to see automated blocks.

I might turn the question back to you and ask if your support for your organization or the VPN service it uses does automated filtering that has for some reason decided some part of ibiblio or UNC is verboten?

If for some reason you’re uncomfortable sharing more details about the failure(s) you’re seeing, please let me know and we’ll open a private ticket.

I’ve only tried accessing ibiblio from SEL’s network using an ordinary web browser. No matter what page on ibiblio, the error is simply: “The page cannot be displayed”.

Thank you for checking into the automated address block list for me. I’ll take this information back to the IT folks at SEL to see if perhaps they have ibiblio blocked for some reason.

It would be very helpful if you could give some specific URLs here at ibiblio and the HTTP response codes you’re getting. If you know how to do that, just reply and ignore the rest of this. If not, read on…

An easy way to do that is to use curl, which is available for all the major operating systems and installed by default in various linux distros and on Mac. Here is an example shell session on a Mac where the terminal prompt is a percent sign ("%"):

% curl -D -
HTTP/1.1 301 Moved Permanently
Content-length: 0
Connection: close

So what I did here is use the ‘curl’ command with the “-D” switch (“dump headers”) followed by a “-” to tell it to put those headers right back to standard out instead of to a file, and then lastly I gave it a URL. The next four lines are the output after I hit return, and that first line starting with “HTTP/1.1 301” is the response code. If you’re on Windows, you may be able to enable Windows Services for Linux if it’s not blocked by your employer’s group policies on your machine. You’d then go into the Microsoft store and install a Linux distro such as Debian. That would be by far the fastest/easiest way for you to get a linux environment on your machine where you’re having trouble. There are other ways to get HTTP headers, and possibly somebody will chime in here with one that works better for you.

My company (SEL) doesn’t allow Linux machines on their network, and getting WSL installed will take significant coordination between myself and the IT department.

If this is helpful, I used the Console feature in Chrome’s Developer Tools to extract an error message from my failed attempt at visiting

`Failed to load resource: the server responded with a status of 503 (Service Unavailable)`