What is the purpose of route tagging during redistribution between routing domains?

What is the purpose of route tagging during redistribution between routing domains?

• A. To assign a metric that increases path cost.
• B. To apply administrative distance changes.
• C. To mark redistributed routes so they are not reintroduced back into the original domain.
• D. To log redistributed routes in a separate table.

Answer: (C)

Route tagging is used to prevent loops when routes cross routing-domain boundaries during redistribution. When routes learned in one domain are redistributed into another, they could be reintroduced back into the original domain if there’s nothing to distinguish them from routes originated there. Attaching a route tag to redistributed routes provides a way to identify them later, so filtering rules (often via route-maps) can block reinsertion into the source domain, stopping a potential feedback loop. The tag itself doesn’t directly change metrics or administrative distance, nor is it primarily for logging; its purpose is to identify redistributed routes to protect against re-redistribution.

Route tagging is used to prevent loops when routes cross routing-domain boundaries during redistribution. When routes learned in one domain are redistributed into another, they could be reintroduced back into the original domain if there’s nothing to distinguish them from routes originated there. Attaching a route tag to redistributed routes provides a way to identify them later, so filtering rules (often via route-maps) can block reinsertion into the source domain, stopping a potential feedback loop. The tag itself doesn’t directly change metrics or administrative distance, nor is it primarily for logging; its purpose is to identify redistributed routes to protect against re-redistribution.