What does the subnet manager assign to ports?
Why C is the answer
LIDs
Local identifiers address ports in a subnet.
In detail
- Local identifiers address ports in a subnet.
- LIDs address ports in a subnet.
Use case
An illustrative scenario, not a real incident.
The subnet manager gives each port a LID, so traffic can be addressed.
See it in different ways
flowchart LR A["Discover fabric"] --> B["Assign LIDs"] B --> C["Program routing tables"] C --> D["Ports go Active"] D --> E["Standby SM takes over on failure"]
stateDiagram-v2 [*] --> Down Down --> Initializing: link comes up Initializing --> Armed: SM assigns a LID Armed --> Active: SM finishes the configuration Active --> [*]
sequenceDiagram participant P0 as Subnet manager participant P1 as Port P0->>P1: Assign LID P1-->>P0: Active
Key point: The SM assigns LIDs.
Why the other options are wrong
- A. MAC vendors
- Vendors are set by manufacturers.
- B. BGP ASNs
- ASNs are for BGP.
- D. VLAN IDs
- VLANs are for Ethernet.