Configuration
To enable node protection, configure the following tiebreaker settings with a specified tiebreaker index. The significance of the index will be covered later in Chapter 14 of the book.
The TI-LFA node protection in the context of router IS-IS is enabled, as shown in the following snippet. A tiebreaker index must be configured, and the value 200 has been chosen strategically for this book. Its significance will be examined during the tiebreaker scenario discussed later:
P2
router isis IGP address-family ipv4 unicast fast-reroute per-prefix tiebreaker node-protecting index 200
After activation, the TI-LFA backup path calculation on the P2 router includes node protection as an additional constraint for all primary paths through the P2–P3 link, and it avoids transiting through the P3 router, as shown in the following diagram.
Figure 10.2 – TI-LFA node protection
The subsequent section validates the backup...
