フリー問題

問題文

In one design the link between two peer switches and the uplinks toward the core all land on a single module of each switch. A reviewer says the simple arrangement leaves a hole. Which pair of statements describes the hole and the way the design closes it?

選択肢

1. A failure of that module leaves the switch with no path onward while it still draws traffic from below, and a tracked list of those interfaces makes the primary device keep its keepalive messages and bring its downstream bundles back up.
2. A failure of that module leaves the switch with no path onward while it still draws traffic from below, and a tracked list of those interfaces makes the primary device stop its keepalive messages and bring its downstream bundles down.
3. A failure of that module leaves the switch with a longer path onward while it stops drawing traffic from below, and a tracked list of those interfaces makes the primary device stop its keepalive messages and bring its downstream bundles down.
4. A failure of that module leaves the switch with a longer path onward while it stops drawing traffic from below, and a tracked list of those interfaces makes the primary device keep its keepalive messages and bring its downstream bundles back up.