Question about core update 126 and the site https://wetransfer.com

[gdgiannop]

We use the site https://wetransfer.com to upload files to colleagues, so that they can download them by using a
link provided by the site after the upload completes.
We use the free option which allows files sizes upto 2G, but our files are always below 300 Mbytes.
Up to core update 124, we could upload files.
With core update 126, we can not upload files unless the file size is tiny. For instance, we can not
upload files of 150 Mbytes.
Uploading interrupts and start from 0 byte again and again.
The session is https/443.
Is there any change in core update 126 that could affect file-uploading from browsers that use ipfire proxy
Thank You.
George G.

[Deepcuts]

Did a quick test upload and it is working just fine.

I am using transparent proxy on http without any setting in browsers.
https sites are bypassed in proxy so IPFire does not interfere with https://wetransfer.com/ unless you did some sort of SSL bump and you are intercepting/using SSL sites also.

[gdgiannop]

Thank you for your feedback.
With my local network setup, I can not avoid the proxy. Both the ipfire proxy and firewall are in the data path.
I use "IPFire 2.21 (i586) - Core Update 126" with usual-standard settings.
My problem persists and I keep on checking and testing,
Best Regards

[Deepcuts]

So you are using the proxy for SSL sites also?

[gdgiannop]

Yes, on the browser, I use the proxy for "all protocols".
Today, I did a test:
On one specific PC, I changed the browser settings to point to another ipfire i586 ver124 (not updated yet),
which is located in another building (within our intranet).
All worked fine (slower but successfully), uploading to https://wetransfer.com was fine too.
It seems to me that ver 126 has brought about my problem.
Many Thanks

[gdgiannop]

Our browser is Firefox Quantum 65.0 (64-bits)
and the proxy settings:

[rodneyp]

Having to set this proxy manually on each workstation is administratively more complex. It's the type of configuration my former ISP was recommending 20 years ago, primarily to minimise download traffic.

Simply setting GREEN (and BLUE, if relevant), as per https://wiki.ipfire.org/configuration/network/proxy, should achieve the same, in a much more manageable way.

[gdgiannop]

I fully agree, my setup is very "manual" and not optimum. However, my
problem is not related to this.
We will consider moving to a more effective and flexible way, possibly with a central pac file per site.
Many Thanks.

[gdgiannop]

After a lot of search, it turned out that our problem affected mainly our sites that are behind VDSL lines and
that it was not related only to core-update 126.
It seems that ipfire after core-update 119 or 120 disabled the "path-mtu discovery" feature.
After commenting out the line "net.ipv4.ip_no_pmtu_dsic = 1" in the /etc/sysctl.conf file and activating
it, our problem disappeared.
We have also noticed that core-update 128 (32-bits) has excluded the above line.
For us, if this is a permanent removal and pmtu-discovery remains active it will be very helpful.