Notes - VTY lines (IOS-XR)

VTY Lines

By default, VTY lines 0-4 are available for access for virtual terminal sessions (i.e. telnet and SSH). The default line template applies to these lines.

You have the ability to control three lines:

• console

• custom (named and applied to the vty-pool)

• default

  • Attributes not defined in line console or line template <name> are taken from line default

You will typically use the default line template. This does not need to be applied to the vty lines, because they use the default line template already.

line default
 width 256

To create your own custom line template use line template <name> and apply it to the specified vty lines via the vty-pool statement. You can either apply the template to the default pool (which must begin at 0), or to a user-defined pool name (which must start at vty number 5 or higher).

line template X
 width 312
!
vty-pool default 0 4 line-template X

The line console template will only apply to the physical console port.

SSH/Telnet

Note that SSH and/or telnet must be explicitly enabled:

ssh server [vrf <name>]
telnet [vrf <name>] ipv4|ipv6 server max-servers <num>

Default vty-pool size

By default, there are 5 vty lines defined. This limits the max number of simulataneous vty sessions to five. To increase this, you can increase the default vty-pool:

vty-pool default 0 <4-99> [line-template <name>]

Further Reading

https://www.cisco.com/c/en/us/td/docs/routers/xr12000/software/xr12k_r3-9/system_management/configuration/guide/yc39xr12k_chapter9.html