The difference between Max Sessions and New Sessions?

[panhanhen]

Hi All,

I would like to ask you as below:

Can you tell me the meaning of Max Sessions and New Sessions in Palo Alto Firewall? what is the difference  between Max Sessions and New Sessions?

[kiwi]

Hi @panhanhen,

Max sessions is the maximum supported sessions that your device can support.

New sessions are new sessions since boot up or can refer to the rate of new sessions per second.

The following CLI command will provide you more information :

> show session info 

In addition you can check live statistics with this CLI command :

> show system statistics session 

I hope this answers your question.

Cheers,

-Kim.

[panhanhen]

How to calculate Max Session? Max Session for one hour or others?

[santonic]

You don't calculate max sessions. It's a hardware specifications which depends on PA appliance you have. 

[kiwi]

Hi @panhanhen,

As santonic stated the maximum sessions is a fixed value depending on your hardware.  Some examples :

PA-3020 : 250,000 max sessions

PA-3050 : 500,000 max sessions

PA-5020 : 1,000,000 max sessions

PA-5050 : 2,000,000 max sessions

You can compare the max sessions per hardware here :

https://www.paloaltonetworks.com/products/product-selection

Cheers,

-Kim

[panhanhen]

Max session is the session per second or session per hour or others?

[santonic]

It's concurrent sessions. 

Or with other words: the number of sessions at specific moment. If you are at 100% a new session coming through FW won't be established. Current sessions won't be affected. Once an existing sessions timeouts/disconnects.. FW will be able to establish a new session.

[BPry · Accepted solution]

@panhanhen I think your confusing the max session capacity and the connections per second capacity. The maximum session is exactly that, that number is the highest number of sessions that your firewall can handle at any given time. The connections per second rate is how many new sessions can form in any given second; since the firewall has to process a lot more informaiton at the start of a new session the cps rate is much lower than what your max session limit is. At the start of a new session the firewall has to determine what security policy that session falls under, what application it's using, if it's allowed, and if it matches anything else that your firewall is setup to monitor. Whereas an existing session can take the same session path and the firewall just 'checks' in on it and verifies that the application hasn't changed and runs it against any antivirus, spyware, and other such profiles.