Cisco SNMP Driver Overview
The driver is implemented in openl2/switches/connect/snmp/cisco/connector.py
This Cisco driver inherits the standard MIB methods from SnmpConnector() for interface up/down and description.
For VLAN management, the Cisco driver implements two access methods.
The Old-Style Catalyst Way
Older Catalyst switches use the Cisco proprietary VTP MIB for vlan management. If VLANs are found in this MIB, the devices is assumed to use it, and self.use_vt_mib = True is set.
Newer CBS switches
- Newer CBS switches use for of the standard MIB, e.g. Q-Bridge MIB for VLAN management.
This has only be been tested a CBS-350 switches !
There are some things to note:
- Switch ports have several mode:
access - ie single untagged frames trunk - dot1q encapsulated general - access both untagged and tagged frames
In general mode, the untagged vlan is read from and written to the “dot1qVlan” MIB ID (.1.3.6.1.2.1.17.7.1.4.5.1.1.<ifIndex>)
In access mode, untagged vlan is read from and written to “dot1qVlanCurrentUntaggedPorts” MIB id (.1.3.6.1.2.1.17.7.1.4.2.1.5.<counter>.<vlan-id>)
- interface GigabitEthernet1
switchport mode general switchport access vlan 1150 switchport general pvid 500
The port mode is read from the vlanPortModeState mib (.1.3.6.1.4.1.9.6.1.101.48.22.1.1.<ifindex>), where:
10 = General
11 = Access
12 = Trunk