[squid-users] Strange Problem with IE over WLAN: IE hangs on certain files

[Rietzler, Markus (RZF, Ref 312 / <RIETZLER_SOFTWARE>)]

we have the following setup:

clients with windows7 and IE11 or Edge.
they have configured a squid proxy (3.5.20). squid is used for access to intranet and internet. the squid it self talks to different central proxies (internet, intranet) and they are talking to dmz proxies for internet access.

so Client -> (user) proxy -> (central) proxy internet -> dmz proxy -> internet
                          -> (central) proxy intranet -> intranet

we now see the folling problem:

when the clients are connected via wlan IE will hang on certain files and can't load them. one of the files is a javascript file and so the page itself is not loaded and waits and waits and waits. when you use the developer tools you can see the contents of the javascript file but IE can't "finish" loading. 

the same file via wired connection is working without any problems. with all the caching on the different stations (client, proxy, central proxy) it is a bit complicated to narrow the problem down. we have so far examined that the size seems to matter. the javascript file with a size of 4039 bytes causes troubles. we also saw this behavior with files the same size. if we add a few lines and bytes to the that file it is working.

it seems not to make a difference whether if we talk about intranet or internet.
problem is, this error is a bit hard to reproduce. if IE is able to load the file then (for a certain time) it is working every time. so we don't know what happens if IE is not able to load the file.

the only thing that is clear at the moment is that a wired connection will work and wlan will cause troubles.

is it a client side problem or a squid problem? sure there are differences if connected via wlan or wire but which? and when how do they influence squid and the connection?

any hints, ideas...


Mit freundlichen Grüßen

Markus Rietzler