Support Cisco Small Business (CBS) switches in PortAdmin

[lunkwill42]

Is your feature request related to a problem? Please describe.

Users have asked for this on the nav-users mailing list. Specifically, a user with Cisco CBS250 switches finds them to work ok in NAV in most aspects except for PortAdmin.

Analysis reveals that these switches do not use Cisco's usual proprietary solution for SNMP VLAN management (community-indexing BRIDGE-MIB per VLAN), but instead provides full support for Q-BRIDGE-MIB (I'm not sure why this line of switches is different, but I suspect they may be a brand of switches that Cisco have bought out from some other vendor).

PortAdmin automatically chooses between a set of management handlers based on the device vendor. When a device reports its enterprise ID as Cisco (9), it selects the Cisco-specific SNMP backend, which uses the community-indexing method to manage VLAN configuration. This is useless on CBS.

Simple access VLAN configuration appears to work if PortAdmin is forced to select the generic SNMP management handler, which employs the IETF RFC-based implemention of Q-BRIDGE-MIB. However, something is still amiss when attempting to configure trunk ports. It seems the commands the generic SNMP back-end sends is unable to properly change the port mode from access to trunk, and also to configure specific trunk VLANs. It seems somehow able to set a native VLAN for a port that was already in trunk mode.

Describe the solution you'd like

• Setting access port VLAN on a Cisco Small Business switch from PortAdmin should work #3249
• Configuring/deconfiguring a trunk port and its native and trunk VLANs on a Cisco Small Business switch from PortAdmin should work.

Additional context

Cisco Business 250 Series Smart Switches Data Sheet

[lunkwill42]

Davide Miccone provided some switches for testing, these have a sysObjectID of 1.3.6.1.4.1.9.6.1.1004.10.1. Browsing Cisco's enterprise MIB tree reveals that they have two separate branches for Cisco SB (small business) and Cisco SMB (small and medium business) products:

.iso(1).org(3).dod(6).internet(1).private(4).enterprises(1).cisco(9).otherEnterprises(6).ciscoSB(1)

and

.iso(1).org(3).dod(6).internet(1).private(4).enterprises(1).cisco(9).otherEnterprises(6).ciscoSMB(2)

I don't know for certain, but I would assume anything with a sysObjectID prefix of 1.3.6.1.4.1.9.6 would behave not like a Cisco device, so I would suggest the backend handler selection routine in NAV should make an exception for this prefix, even though the enterprise ID is 9.