For more information regarding the security incident at F5, the actions we are taking to address it, and our ongoing efforts to protect our customers, click here.

Forum Discussion

Amar_A_361783's avatar
Amar_A_361783
Icon for Nimbostratus rankNimbostratus
Aug 21, 2018

Why is Persistence required for long-live connection too?

I need to understand is even persistence required for application like SSH? SSH & say other stateful protocol which holds session with the client for long period, what is the use of applying persist...
application delivery
LTM
youssef1's avatar
youssef1
Icon for Cumulonimbus rankCumulonimbus
Aug 22, 2018

Hi,

 

If you have multiple backend (Statfull Web Services) you need to be redirect to the same server. In this case you need persistence:

 

  • WEB Service (you can use L7 persistance as cookie)
  • TCP Service as SSH (you can use sourceadress persistance)

In your case with ssh you need to use source address pers. And if you have only one Pool memeber (backend) or several pool memebers (stateless) you don't need persistance.

 

But you have to pay attention to your TCP profile. you have to keep in mind that your SSH VS has a TCP profile. TCP use a 5 minute (300 seconds) idle timeout value. So you will probably deconnected each F5 (I'am not sure but for FTP or SFTP I already had this behaviour). To fix this, create a new TCP profile for your SSH VS and change the idle timeout to something that makes sense for your environment (30mn).

 

Info: Overview of BIG-IP idle session time-outs

 

https://support.f5.com/csp/article/K7606

 

Regards