Query on SSH

[Johnson Punniyalingam]

what is the maximum number of connection we can have in SSH ?

I did check the man ssh_config file -> points to maximun 10

or it depends on number of pseudo devices

And how about the "batch jobs running" using SSH

does this also require me to increase pseudo devices

[Michal Kapalka (mikap)]

hi,

i thinks ists depend on you server if its enough powerfull and also if you have enough
pseudo devvices.

check this discusion :

http://www.unix.com/unix-advanced-expert-users/46982-max-numer-connections-per-sshd.html


mikap

[dirk dierickx]

i'm not aware of SSH having this limitation. if there is a limit at all, it will be whatever the OS limits.

[Viktor Balogh]

you can look for used pty's in glance -> press "t" for "system tables"

You can query the number of ptys from the kernel with kmtune like this: (in 11iv2/v3 look for the kctune command)

# kmtune -q npty
Parameter Current Dyn Planned Module Version
===============================================================================
npty 60 - 60

[mvpel]

The "MaxSessions" option in sshd_config is the maximum number of open sessions per network connection, not per system.

That option is tied to a feature in SSH 4.x and up called "connection multiplexing," which allows you to start additional SSH sessions over an existing TCP connection, via the use of a socket:

http://www.debian-administration.org/articles/290

The "MaxSessions" option was introduced in OpenSSH 5.1 to allow more fine-grained administrative control of the multiplexing feature.

[Johnson Punniyalingam]

Thanks to all, :)