Intermediate System to Intermediate System (IS-IS) is a routing protocol designed to move information by determining the best route for datagrams through a packet-switched network.
A two-level hierarchy is used to support large routing domains. A large domain may be divided into areas. Routing within an area is referred to as Level 1 routing. Routing between areas is referred to as Level 2 routing. A Level 2 Intermediate System (IS) keeps track of the paths to destination areas. A Level 1 IS keeps track of the routing within its own area. For a packet going to another area, a Level 1 IS sends the packet to the nearest Level 2 IS in its own area, regardless of what the destination area is. Then the packet travels via Level 2 routing to the destination area, where it may travel via Level 1 routing to the destination. An IS in both Level 1 and Level 2 is referred to as Level-1-2.
NSX support for the IS-IS protocol is currently experimental.
- Log in to the vSphere Web Client.
- Click Networking & Security and then click NSX Edges.
- Double-click an NSX Edge.
- Click Routing and then click IS-IS.
- Click Edit and then click Enable IS-IS.
- Type the System ID and select the IS-IS type.
Level 1 is intra-area, Level 2 is inter-area, and Level 1-2 is both. Level 2 routers are inter-area routers that can only form relationships with other Level 2 routers. Routing information is exchanged between Level 1 routers and other Level 1 routers. Likewise Level 2 routers only exchange information with other Level 2 routers. Level 1-2 routers exchange information with both levels and are used to connect the inter-area routers with the intra-area routers.
- Type the Domain Password and Area Password. The area password is inserted and checked for Level 1 link state packets, and the domain password for Level 2 link state packets.
- Define the IS-IS areas.
- Click the Add icon in Areas.
- Type up to three area IP addresses.
- Click Save.
- Configure interface mapping.
- Click the Add icon in Interface Mapping.
- Choose the Circuit Type to indicate whether you are configuring the interface for Level-1, Level-2, or Level-1-2 adjacency.
- Hello Interval displays the default interval in milliseconds between hello packets that are sent on the interface. Edit the default value if required.
- Hello Multiplier displays the default number of IS-IS hello packets a neighbor must miss before it is declared down. Edit the default value if required.
- LSP Interval displays the time delay in milliseconds between successive IS-IS link-state packet (LSP) transmissions. Edit the default value if required.
- Metric displays the default metric for the interface. This is used to calculate the cost from each interface via the links in the network to other destinations. Edit the default value if required.
- Priority displays the priority of the interface. The interface with the highest priority becomes the designated router. Edit the default value if required.
- In Mesh Group, type the number identifying the mesh group to which this interface belongs. Edit the default value if required.
- Type the authentication password for the interface and click OK. Edit the default value if required.
- Click Publish Changes.