A network administrator is troubleshooting a BGP peering session between two autonomous systems. The session is established, but routes are not being exchanged. The administrator checks the BGP configuration and finds that the neighbor statement includes a route-map that is applied in the inbound direction. What should the administrator check next?

Verify that the router has a default route in its routing table.

Verify that the BGP session is using MD5 authentication.

Verify that the route-map contains a permit statement that matches the expected prefixes.

Verify that the neighbor's AS number is correct.

What is the primary purpose of Unicast Reverse Path Forwarding (uRPF) on a router?

To encrypt packets between two routers

To filter packets based on destination IP address

To load balance traffic across multiple paths

To verify that the source IP address of a packet is reachable via the interface it arrived on

Which type of attack is specifically mitigated by implementing anti-spoofing filters such as uRPF?

Denial of service attacks using TCP SYN floods

A network engineer is troubleshooting intermittent connectivity issues after enabling uRPF in strict mode on the edge router. Internal users report that some legitimate traffic is being dropped. The router has asymmetric routing paths for certain destinations. What is the most likely cause and the best solution?

uRPF strict mode is dropping packets because the return route does not point back to the same interface; switch to loose mode

The firewall is blocking the return traffic; disable the firewall

uRPF is blocking packets from legitimate internal addresses because they are not in the routing table; add static routes

uRPF is working correctly and the drops are due to spoofed packets; ignore the reports

GIAC Defensible Security Architect

Domain 2Objective 2

Fundamental Layer 3 Defense GDSA Practice Questions (Page 5)

Part of the Network Security Fundamentals domain, which makes up ~25% of our current practice bank. GIAC (SANS) does not publish an official question count, but from its 120-minute exam (~50–80 total, ~13–20 in this domain), expect 3–5 from this objective — we provide 36 practice questions to prepare you well beyond it. (estimate)

36questions here

8free pages

10concepts

Questions 21–25

21application · medium
A network administrator is troubleshooting a BGP peering session between two autonomous systems. The session is established, but routes are not being exchanged. The administrator checks the BGP configuration and finds that the neighbor statement includes a route-map that is applied in the inbound direction. What should the administrator check next?
Select an answer first
22foundation · easy
What is the primary purpose of Unicast Reverse Path Forwarding (uRPF) on a router?
Select an answer first
23foundation · easy
Which type of attack is specifically mitigated by implementing anti-spoofing filters such as uRPF?
Select an answer first
24expert · hard
A network engineer is troubleshooting intermittent connectivity issues after enabling uRPF in strict mode on the edge router. Internal users report that some legitimate traffic is being dropped. The router has asymmetric routing paths for certain destinations. What is the most likely cause and the best solution?
Select an answer first
25foundation · easy
Which tool is commonly used to analyze Layer 3 traffic patterns and identify anomalies such as unusual source IP addresses or abnormal packet rates?
Select an answer first

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Fundamental Layer 3 Defense GDSA Practice Questions (Page 5)

Questions 21–25

What is the primary purpose of Unicast Reverse Path Forwarding (uRPF) on a router?

Which type of attack is specifically mitigated by implementing anti-spoofing filters such as uRPF?

Which tool is commonly used to analyze Layer 3 traffic patterns and identify anomalies such as unusual source IP addresses or abnormal packet rates?

Keep studying — Network Security Fundamentals