what is the difference between (ip ssh maxstartups 5) and (vty 0 4)

[Sudqi]

what is the difference between (ip ssh maxstartups 5) and (vty 0 4), as i know vty 0 4 is to make 5 users connect to the device in the same time, but what is the needed for (ip ssh maxstartups)?

[luis_cordova]

Hi @Sudqi 

The line vty 0 4 command allows you to access the line configuration mode, where you can enter the parameters for those 5 vty lines.
You must keep in mind that more than 5 lines can be enabled on the devices.

The ip ssh maxstartups [number] command allows you to limit the number of simultaneous connections per SSH

https://www.cisco.com/c/en/us/td/docs/ios-xml/ios/security/d1/sec-d1-cr-book/sec-cr-i3.html#wp3414043258

Regards

[Sudqi]

thank you Iuis for the reply

"You must keep in mind that more than 5 lines can be enabled on the devices" 

i doesn't understand this sentence, what is the lines used for?

[luis_cordova]

Hi @Sudqi 

"You must keep in mind that more than 5 lines can be enabled on the devices" 

I meant that in many cisco devices you can enable more than 5 vty lines, for example, with the command line vty 0 15, where you can configure the parameters for 16 vty lines.

https://community.cisco.com/t5/other-network-architecture/how-many-vty-lines-are-there/td-p/176783

Regards

[Sudqi]

@luis_cordova 

but maxstartups  up to 128 !

[luis_cordova]

Hi @Sudqi 

That's right.

In fact, there are versions of IOS that allow many more vty lines.
Check out this community discussion:

https://community.cisco.com/t5/firewalls/best-practices-for-securing-vty-lines/td-p/2105377

Regards