Documentation for "Maximum Header Field Length" and "Maximum Header Length" in HTTP-Profile. I Cant find it anywhere.

[Holger-Soeren Dretzke]

Documentation for "Maximum Header Field Length" and "Maximum Header Length" in HTTP-Profile. I Cant find it anywhere.

[Marcelo Oguma de Souza]

This doc mentions some limits related to headers https://support.citrix.com/article/CTX118716/netscaler-appliance-system-limits

[Holger-Soeren Dretzke]

I am looking for these entries in HTTP-Profile. The posibble values are the same for both entries.

[Subhojit Goswami]

Hi Holger,

Please visit the following link for the documentation: https://docs.netscaler.com/en-us/citrix-adc/current-release/system/http-configurations.html#:~:text=The%20header%20size%20can%20be,to%20use%20these%20HTTP%20configurations.

One quick thing to note is that the max value mentioned in the document is not correct. Hence, we will rectify it asap.

The following are the values for both Maximum Header Length and Maximum Header Field Length

Default: 24820 B

Min: 2048 B

Max: 122880 B

Thanks and Regards,

Subhojit Goswami

[Holger-Soeren Dretzke]

Hi Subhojit,

thank you for the quick answer. We do need this settings, because we are having trouble in the past and with actual applications using authentication. Sometimes the cookie for some Users is quit huge and than the session is corrupted.

In the past we have used the CLI to configure only the maxHeaderFieldLen:

maxHeaderFieldLen Maximum header field length Default value: 16384 Minimum value: 2048 Maximum value: 122880

To be more specific this is the reason why I ask, what is the difference between the two options now in the GUI HTTP-Profile?

Thank you and greets

Holger-Sören Dretzke

[Subhojit Goswami]

Hi Holger,

So, Maximum Header Length parameter in the HTTP Profile caters to the maximum value the NetScaler will check for the entire header. So, for example if you set 2048 B, then NetScaler will check for that many bytes to find the end of the entire header, if not found, then it will mark the request as invalid.

Whereas, Maximum Header Field Length parameter in the HTTP Profile caters to the maximum value the NetScaler will check for each field present within the HTTP header, eg in the attached pic: Host, User-agent, etc. So, for example if you set 2048 B, then NetScaler will check for it, and if the header fields exceed that specified value, then the HTTP request will be marked invalid.

I hope this answers your query.