Reference Guide

798 | Security
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VTY Line and Access-Class Configuration
Various methods are available to restrict VTY access in Dell Networking OS. These depend on which
authentication scheme you use — line, local, or remote:
Dell Networking OS provides several ways to configure access classes for VTY lines, including:
• VTY Line Local Authentication and Authorization on page 798
• VTY Line Remote Authentication and Authorization on page 799
VTY Line Local Authentication and Authorization
Dell Networking OS retrieves the access class from the local database. To use this feature:
1. Create a username
2. Enter a password
3. Assign an access class
4. Enter a privilege level
Line authentication can be assigned on a per-VTY basis; it is a simple password authentication, using an
access-class as authorization.
Local authentication is configured globally. You configure access classes on a per-user basis.
Dell Networking OS can assign different access classes to different users by username. Until users attempt
to log in, Dell Networking OS does not know if they will be assigned a VTY line. This means that
incoming users always see a login prompt even if you have excluded them from the VTY line with a
deny-all access class. Once users identify themselves, Dell Networking OS retrieves the access class from
the local database and applies it. (Dell Networking OS also subsequently can close the connection if a user
is denied access).
Table 44-1. VTY Access
Authentication Method
VTY access-class
support?
Username
access-class
support? Remote authorization support?
Line YES NO NO
Local NO YES NO
TACACS+ YES NO YES (with Dell Networking OS 5.2.1.0
and later)
RADIUS YES NO YES (with Dell Networking OS 6.1.1.0
and later)
Note: If a VTY user logs in with RADIUS authentication, the privilege level will be applied from the
RADIUS server only if RADIUS authentication is configured.