Understanding Static Routes in Junos

D

The routes with a lower route preference are always used to route traffic. Preference 5 is the default preference for static routes.

The configuration shown is a static route with a default route (0.0.0.0/0) and two next-hop options. The syntax of the command is as follows:

static route <destination> qualified-next-hop <nh1> preference <p> next-hop <nh2>

Here, <destination> is the default route (0.0.0.0/0), <nh1> is the primary next-hop (172.30.25.1), <p> is the preference value (7), and <nh2> is the secondary next-hop (172.30.25.5).

Now, let's analyze the options given in the question:

A. The next-hop 172.30.25.1 is selected because the address has the lowest value. This statement is incorrect because the configuration does not use the "preference" attribute to select the next-hop. The "preference" attribute is only used to influence the routing table's decision-making process when multiple routes to the same destination exist. In this case, there is only one route, so preference does not come into play.

B. The next-hop 172.30.25.1 is selected because it is listed first. This statement is incorrect because the order in which the next-hop options are listed in the configuration does not matter. The router uses the primary next-hop unless it is unavailable, in which case it uses the secondary next-hop.

C. The next-hop 172.30.25.1 is selected because it is the lowest protocol preference. This statement is incorrect because the configuration does not specify any protocol preferences. The "preference" attribute is not used for protocol preference but rather to determine the route's priority.

D. The next-hop 172.30.25.5 is selected because it is the lowest protocol preference. This statement is incorrect for the same reasons as option C.

Therefore, none of the given options are correct. The router will use the primary next-hop (172.30.25.1) unless it is unavailable, in which case it will use the secondary next-hop (172.30.25.5).