Global Who-Is Router

Overview

• A router looking for a router to one or more networks.
• It sends out a “Who-Is Router to Network” without specifying the network number, and all routers in the network respond with I-Am Router.
• If the router specifies the network, it’s not included in this check.
• Who-Is Router and I-Am Router are both broadcast, so on a large network if they all respond at the same time, it causes a lot of traffic.
• Fails if we see one or more sources sending out more than one Global Who-Is Router.

Why it fails

• The router or controller was offline, came back online, and is trying to figure out if its information is up to date.
• The router is configured to periodically ask for this.

How to fix it

• Identify source device sending the Global Who-Is Router.
• Check to see if router is stable and staying online.

Watch us troubleshoot Global Who-Is router in this live webinar on a university. Skip ahead to 1:41 for the Global Who-Is router diagnostic check.