Layer 2 Topology
The Layer 2 topology is drawn according to the bridge protocol and any of Link Layer Discovery Protocol (LLDP), Neighbor Discovery Protocol (NDP), Cisco Discovery Protocol (CDP), and Spanning Tree Protocol (STP). It displays the network structure and status information such as Layer 2 connections among devices on the subnet, link status, and device status.
The Layer 2 topology supports delayed deletion, which allows invalid Layer 2 links to be displayed as dotted lines in the topology for a specified time period, and finally deletes the invalid lines when the delay expires.
The Multiple Spanning Tree Protocol (MSTP) topology is drawn automatically according to the spanning tree information of the devices. It shows the topology of each spanning tree, including device status and link status.
Operation Procedure
- Click the Resource tab.
- Select View Management > IP Topology in the navigation tree.
- Double-click IP Topology in the topology navigation tree and then double-click a non-empty subnet in the IP topology page, or double-click a subnet in the topology navigation tree.
Functions
- Enable Delayed Delete: Click
on the toolbar of the topology. In the dialog box opens, select the Enable Delayed Delete menu.
- View MSTP topology: Click
on the toolbar of the topology, and select CIST or an instance in the area. Nodes or links not in the CIST or the instance are grayed out.
- View MST details: Click
on the toolbar of the topology.
- Path Topology: Right-click on a blank area of the Layer 2 topology and then select Path Topology from the shortcut menu. In the dialog box that appears, type the source and destination IP addresses and click OK.
- Highlight MACsec Links: Right-click a blank area of the Layer 2 topology, and then select Highlight MACsec Links from the shortcut menu.
a. Activated MACsec Links: Highlights established MACsec links and grays the other links out.
b. Unactivated MACsec Links: Highlights each link between a MACsec-enabled interface and an interface that does not support MACsec or is not configured with MACsec (including failing the MACsec configuration), and grays the other links out.
c. Unconfigured MACsec Links: Highlights links that support MACsec but are not in the active state, and grays the other links out.
d. MACsec-Capable Links: Highlights links that support MACsec but are not configured with MACsec, and grays the other links out.
e. Links Not Supporting MACsec: Highlight the links that do not support MACsec, and grey out the other links.
- Cancel MACsec Highlight: Right-click a blank area of the Layer 2 topology, and then select Cancel Highlighting MACsec Links from the shortcut menu.
- Establish MACsec Link: Right-click a link that is configured with MACsec but is not in the active state on the Layer 2 topology, and then select Establish MACsec Link from the shortcut menu to enable MACsec protection for the link.
- Remove MACsec Link: Right-click an established MACsec link on the Layer 2 topology, and then select Remove MACsec Link from the shortcut menu to disable MACsec protection for the link.
Precautions
- LLDP, NDP, CDP, or STP should be enabled in order to ensure the preciseness of Layer 2 topology and reduce the resource use.
- The Layer 2 topology requires SNMP to be enabled, and the MIBs related to 802.1d and 802.1q to be implemented.
- Two switches that connect with each other through a hub are displayed as direct connection in the topology.
- The representation of a link becomes a dotted line when the MAC addresses of the nodes on both sides of the link are aged out. The link is finally removed from the topology when the specified lifetime is due.
- Changes to the lifetime for delayed deletion apply both to the links aged out after the changes and the existing links.
- If the links in all the instances are blocked, the blocked links are marked
in the Layer 2 topology. If the links in a certain MSTP instance are blocked, the blocked links are marked on one side in the MSTP topology.
Related Topics