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Brian_Brehart
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Feb 18, 2020

Compression stripped by Silverline

We've recently experienced slowdowns serving web pages, and here's something we've found:

Apparently, when traffic passes through the WAF, the WAF strips out the following line: Content-Encoding: gzip. We serve pages compressed with GZIP, but, from what we can see, the WAF strips that compression, severely slowing down the page delivery. Does this make sense to anyone, and is there a way to remediate this issue?

 

 

2 Replies

  • Hi,

     

    You can open ticket to F5 Silverline team. TAC team will immediatly help you to identity the problem.

  • F5 Silverline inserts a Via header in all HTTP requests sent to back-end web servers.

    • However, some web servers do not compress data if a request contains a "Via" header.
    • This can lead to longer load times for clients as well as increased bandwidth usage.

    Please consult your server documentation for details. 

    IIS server:

    https://docs.microsoft.com/en-us/iis/troubleshoot/performance-issues/troubleshooting-iis-compression-issues-in-iis6-iis7x

    appcmd set config -section:system.webServer/httpCompression /noCompressionForHttp10:"False" /noCompressionForProxies:"False" /commit:apphost

    NGINX

    https://nginx.org/en/docs/http/ngx_http_gzip_module.html#gzip_proxied

    Syntax: gzip_proxied off | expired | no-cache | no-store | private | no_last_modified | no_etag |auth | any ...;

    Default:

    gzip_proxied off;

    Context: http, server, location