JUNOS Enterprise Routing

Chapter Review Answers

1. Answer: C. There is no default password on a Juniper router in the factory default configuration. A single user, root, will be configured with no password.

2. Answer: B. The class of superuser allows users to issue any command that they desire on the router. The other options listed are not supported classes.

3. Answer: A. At the end of a filter chain, if a packet has not matched any other term, it will be discarded. Special care must always be taken when writing a filter to allow traffic that would otherwise be denied by the final implicit discard at the end of the filter.

4. Answer D. If a filter is applied to the loopback interface, any traffic local to the router can be protected, including routing protocol, ICMP, and FTP traffic.

5. Answer: D. You can use the show firewall command to view counters defined in any firewall filter. Also, any policer that is referenced in a filter will have a counter automatically created and viewed by this command. The show policer command will only show the counter for policers applied directly to the interface.

6. Answer: A, C. Both firewall filters and Unicast RPF will help to avoid packets with spoofed IP addresses. Unicast RPF could provide for more dynamic and automatic filtering.

7. Answer: A, B, D. Policers must specify bandwidth and burst size limit. Also, once a packet hits one of the limits, an action to either hard- or soft-police must be specified.

8. Answer: A, B. A fail filter matches on packets that fail the RPF check. You could use ...