NorthStar Planner Virtual Local Area Networks Overview

As modern Ethernet technologies mature and MPLS technologies such as VPLS are being used to extend Layer-2 VLANs across the MAN and the WAN, there is an increasing need for a tool that provides visibility into layer-2 VLANs in addition to the IP and MPLS layers. NorthStar Planner has risen to the challenge by providing a whole suite of capabilities in support of VLANs.

NorthStar Planner automatically constructs the network's VLANs via a VLAN Discovery task that uses a combination of SNMP MIBs polling and CLI show commands. Combined with configuration file parsing, all the details related to each device, VLAN, and spanning tree are derived by the tool and easily accessed by the user. Furthermore, the VLAN View window and the L2 STP subview on the topology map allow the user to get a clear logical view as well as status information for each individual VLAN and spanning tree. Besides gaining visibility into the VLANs in the network, NorthStar Planner also allows the network planner to construct VLANs from scratch via the VLAN Wizard. If desired, the VLAN configlet generation feature can be used to create configuration statements that can be pushed into the router/switch by the network engineer.

Apart from just displaying the nodes and links that are part of a spanning tree, STP topology uses coloring to signify the role of each node/link to make it easily understandable to the user. Devices that belong to a spanning tree can be further grouped together by defining access domains to depict the real physical network. An access domain is a group of physically connected layer 2 devices, where all the VLAN IDs are unique, i.e. devices that have the same VLAN id in an access domain belong to the same VLAN. As direct physical connectivity cannot be extracted, IPMPLSView, by default, groups all devices into the default domain. For networks with multiple access domains, users should define the access domains and assign nodes into them properly as explained in the VLAN Modification and Design.

Layer 2 VLAN information is accessible either in online or offline mode. In online mode, you should run the Scheduled Live Network Collection task to collect switches’ Configuration and Switch CLI output. In addition, you should also run the VLAN Discovery task for IPMPLSView to extract the spanning tree information from the switches.

For offline mode, you can collect the configuration files using any third party collector. The SNMP polling on the other hand, is recommended to be performed using our Standalone SNMP poller, as it requires real time interpretation of ongoing polling results to determine the entire MIBs that needed to be polled, so that complete spanning tree information can be obtained. Please contact your Juniper representative for details on the Standalone SNMP poller availability.