On 11/08/17 23:15, Rietzler, Markus (RZF, Ref 312 / <RIETZLER_SOFTWARE>) wrote:
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.

Can you send me a packet trace of the IE<->Squid connection with one of those files going through please? if it can be one where the problem occurs perfect, but if that is too hard a working transfer with one of the problem ones might do.

4039 sounds suspiciously close to the 4096 memory page size. Perhapse the HTTP headers put something like a chunked encoding CRLF or NUL terminator right across the page boundary and some buffer I/O gets stuck.

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?

Connection type does not matter to Squid exactly, its just TCP over either. Though packet loss at the FIN portion of a TCP connection may result in this type of behaviour.

Any type of tunneling or packet level gateway happening differently on the lan or wlan connections? this kind of reminds me of some weird MTU related issues that used to be seen with IPv6 tunnels.

squid-users mailing list
  • [squid-users] ... Rietzler, Markus (RZF, Ref 312 / <RIETZLER_SOFTWARE>)
    • Re: [squi... Amos Jeffries

Reply via email to