350-601 Security Practice Test 5 — 15 Questions

Question 1

An organization is deploying Cisco Nexus 9000 switches with NX-OS and needs to prevent ARP spoofing attacks. The network engineer enables Dynamic ARP Inspection (DAI) on all VLANs. However, some legitimate hosts are unable to obtain IP addresses via DHCP. What is the most likely reason?

Accepted Answer

DHCP snooping is not enabled, so DAI lacks the DHCP snooping binding table.. DAI relies on the DHCP snooping binding table to validate ARP packets. Without DHCP snooping enabled, the binding table is empty, so DAI cannot determine which ARP packets are legitimate, causing it to drop all ARP packets, including DHCP discovery and request messages. This prevents hosts from obtaining IP addresses via DHCP.

Answer

The ARP rate limit on the port is too low, causing all ARP requests to be dropped.

Answer

IP Source Guard is enabled and is blocking ARP packets.

Answer

An ARP ACL is not configured to allow static IP bindings.

Question 2

Which TWO of the following are valid methods to enforce security on a Cisco Nexus switch? (Choose two.)

Accepted Answer

Control Plane Policing (CoPP). Control Plane Policing (CoPP) is a valid security enforcement method on Cisco Nexus switches because it protects the control plane from excessive or malicious traffic by applying QoS policies that rate-limit packets destined for the supervisor module. By filtering traffic such as routing protocols, SSH, or ICMP, CoPP prevents CPU overload and DoS attacks, directly enforcing security at the control plane level.

Answer

SSHv2

Answer

NetFlow

Answer

FabricPath

Question 3

Which TWO security features are used to prevent MAC address flooding attacks on a Cisco Nexus switch? (Choose two.)

Accepted Answer

Port Security. Port Security (A) is correct because it limits the number of MAC addresses allowed on a switch port, preventing MAC flooding attacks by dropping frames from unknown source MACs once the limit is exceeded. DHCP Snooping (D) is correct because it builds a trusted database of IP-to-MAC bindings from DHCP messages, which can be used to validate traffic and prevent MAC spoofing that often accompanies flooding attacks.

Answer

IP Source Guard

Answer

Control Plane Policing

Answer

BPDU Guard

Question 4

Which THREE of the following must be enabled to implement 802.1X authentication with MAB fallback on a Cisco Nexus switch for a mixed environment of 802.1X-capable and non-802.1X endpoints? (Choose three.)

Accepted Answer

AAA authentication with a RADIUS server. Option B is correct because 802.1X authentication requires AAA to communicate with a RADIUS server. The RADIUS server validates the credentials (EAP over RADIUS) and returns an Accept or Reject, which the switch uses to authorize the port. Without AAA and a RADIUS server, the switch has no external authentication authority to process 802.1X requests or MAB fallback.

Answer

MACsec encryption on the port

Answer

A VLAN ACL to redirect traffic

Question 5

Refer to the exhibit. The TACACS+ server at 10.1.1.1 is unreachable. What will happen when a user tries to authenticate to the switch using SSH?

Accepted Answer

Authentication will use the local user database as a fallback.. When the TACACS+ server at 10.1.1.1 is unreachable, the switch will fall back to the local user database for authentication because the 'fallback-to-local' feature is enabled by default in Cisco IOS/IOS-XE for TACACS+ configurations. This behavior ensures that administrative access is not completely blocked if the remote AAA server becomes unavailable, allowing authentication against locally configured usernames and passwords.

Answer

Authentication will be denied immediately.

Answer

Authentication will be attempted against the TACACS+ server repeatedly until timeout.

Answer

Authentication will be attempted against the TACACS+ server without fallback because 'fallback-to-local' is not configured.

Question 6

Refer to the exhibit. The interface showed a security violation 15 seconds ago and has a violation count of 5. What would happen if a frame with source MAC 0011.2233.4477 arrived now?

Accepted Answer

The port will be placed into errdisable state.. The correct answer is B because the port security violation mode is configured as 'shutdown' (the default), and the violation count has reached 5, which exceeds the allowed maximum of 1 (the default). When a security violation occurs and the port is in shutdown mode, the port immediately transitions to the errdisable state, blocking all traffic. Since the frame with source MAC 0011.2233.4477 is not the allowed MAC (0011.2233.4455), it triggers a violation, and the port is placed into errdisable state, as indicated by the violation counter incrementing to 5.

Answer

The frame will be dropped but the port remains up.

Answer

The frame will be allowed because sticky MACs are learned dynamically.

Answer

The frame will be dropped and the violation counter will increment, but the port stays up.

Question 7

Refer to the exhibit. The configuration is intended to provide Layer 2 isolation within VLAN 100 while allowing the promiscuous port (Ethernet 1/1) to communicate with all ports in the community VLAN. However, hosts in VLAN 100 cannot communicate with each other. What is the most likely misconfiguration?

Accepted Answer

The 'switchport private-vlan association trunk' command on Ethernet 1/1 is incorrect; it should be 'switchport private-vlan association mapping' or similar.. The command 'switchport private-vlan association trunk' is invalid for configuring a promiscuous port in a private VLAN. The correct command is 'switchport private-vlan mapping primary-vlan-id secondary-vlan-id' to map the promiscuous port to the primary VLAN and the secondary community VLAN. Without this correct mapping, the promiscuous port cannot forward traffic to hosts in the community VLAN, causing Layer 2 isolation to fail.

Answer

The SVI interface needs 'ip address' to be removed.

Answer

The SVI interface should have 'private-vlan mapping' to the primary VLAN, not the community VLAN.

Answer

The command 'no ip redirects' should not be applied to the SVI.

Question 8

A data center engineer configures an ACL on a Nexus 9000 switch to block all traffic from the management network (10.10.0.0/16) to the production servers (192.168.1.0/24) except for SSH access from a specific jump host (10.10.1.100). The ACL is applied inbound on the management interface. Which ACL entry is correctly ordered to achieve this requirement?

Accepted Answer

permit tcp host 10.10.1.100 192.168.1.0 0.0.0.255 eq 22
deny ip 10.10.0.0 0.0.255.255 192.168.1.0 0.0.0.255
permit ip any any. Option C is correct because ACLs are processed top-down, and the first match wins. The explicit permit for SSH from the jump host (10.10.1.100) must come before the deny for the entire 10.10.0.0/16 range to ensure the exception is honored. The final permit ip any any allows all other non-management traffic, which is necessary to avoid dropping legitimate traffic on the management interface.

Answer

permit ip any any
deny ip 10.10.0.0 0.0.255.255 192.168.1.0 0.0.0.255
permit tcp host 10.10.1.100 192.168.1.0 0.0.0.255 eq 22

Answer

permit tcp host 10.10.1.100 192.168.1.0 0.0.0.255 eq 22
permit ip any any
deny ip 10.10.0.0 0.0.255.255 192.168.1.0 0.0.0.255

Answer

deny ip 10.10.0.0 0.0.255.255 192.168.1.0 0.0.0.255
permit tcp host 10.10.1.100 192.168.1.0 0.0.0.255 eq 22
permit ip any any

Question 9

An engineer needs to ensure that only authorized servers can connect to a specific switch port in a data center. The port connects to a critical database server with fixed MAC address 00:1a:2b:3c:4d:5e. Which configuration is most appropriate?

Accepted Answer

switchport port-security
switchport port-security mac-address 001a.2b3c.4d5e
switchport port-security violation shutdown. Option A is correct because it explicitly binds the specific MAC address 001a.2b3c.4d5e to the port using port security, and sets the violation mode to shutdown, which disables the port if any unauthorized device attempts to connect. This ensures only the authorized database server can use the port, meeting the requirement precisely.

Answer

switchport port-security
switchport port-security maximum 1
switchport port-security violation shutdown

Answer

no switchport port-security
spanning-tree portfast

Answer

switchport port-security
switchport port-security maximum 2
switchport port-security violation protect

Question 10

A Nexus 7000 switch is experiencing high CPU utilization due to control plane traffic. The engineer notices that many packets are being punted to the CPU from the data plane, particularly ARP packets. After examining the CoPP configuration, the engineer sees that the 'arp' class-map is matched in a policy-map with a police rate of 1000 pps and a conform-action of 'transmit'. The current ARP rate is 2000 pps. What is the immediate impact?

Accepted Answer

Approximately half of the ARP packets are dropped, reducing CPU load but potentially causing reachability issues.. The CoPP policy is configured with a police rate of 1000 pps for ARP packets, but the current ARP rate is 2000 pps. Since the rate exceeds the policer, the conform-action 'transmit' only applies to packets within the rate; excess packets are dropped by default (drop action is implicit when no exceed-action is specified). This results in approximately half of the ARP packets being dropped, which reduces CPU load but can cause ARP resolution failures and reachability issues.

Answer

All ARP packets are transmitted normally because the conform-action is 'transmit'.

Answer

The switch applies an ACL to drop all ARP packets.

Answer

Packets are marked down and transmitted.

Question 11

A company uses Cisco TrustSec in its data center to enforce segmentation. Servers in VLAN 10 (Finance) should only communicate with servers in VLAN 20 (ERP) via an application gateway. Which TrustSec component is used to assign a Security Group Tag (SGT) to traffic from the Finance servers?

Accepted Answer

Identity Services Engine (ISE) as the authentication and policy server. In Cisco TrustSec, the Identity Services Engine (ISE) acts as the authentication and policy server that assigns Security Group Tags (SGTs) to endpoints or traffic based on identity and policy. ISE uses 802.1X, MAB, or web authentication to identify the Finance servers and then dynamically assigns the appropriate SGT, which is then used for segmentation enforcement.

Answer

MACsec encryption on the links

Answer

802.1X port-based authentication

Answer

VLAN ACL (VACL) on the switch

Question 12

A data center network engineer wants to encrypt all traffic between two top-of-rack (ToR) switches that are connected via a direct link. The encryption should be transparent to upper-layer protocols and operate at Layer 2. Which technology should be used?

Accepted Answer

MACsec (802.1AE). MACsec (802.1AE) is the correct choice because it provides hop-by-hop encryption at Layer 2, encrypting the entire Ethernet frame (excluding the source/destination MAC and VLAN tag) to secure traffic between two directly connected switches. It operates transparently to upper-layer protocols (Layer 3 and above) and requires no IP-level configuration, making it ideal for encrypting a direct link between ToR switches.

Answer

IPsec VPN

Answer

MKA (MACsec Key Agreement)

Answer

TLS/SSL

Question 13

An engineer is troubleshooting a DHCP issue in a data center VLAN. Clients are unable to obtain IP addresses from the DHCP server. The switch has DHCP snooping enabled on the VLAN, and the DHCP server is connected to a trusted port. The clients are on untrusted ports. Which additional security feature is most likely causing the problem if the DHCP server is on a different subnet and the switch is not configured as a DHCP relay?

Accepted Answer

DHCP snooping with no IP helper address configured. When the DHCP server resides on a different subnet and the switch lacks an IP helper address (ip helper-address) configuration, DHCP snooping will not forward the DHCP broadcast from the client to the server. DHCP snooping relies on the switch to relay DHCP packets across subnets; without the helper address, the broadcast is dropped at the VLAN interface, preventing clients from obtaining IP addresses.

Answer

Dynamic ARP Inspection (DAI)

Answer

Control Plane Policing (CoPP) dropping DHCP packets

Answer

Port security with maximum MAC limit

Question 14

A network administrator wants to prevent IP spoofing attacks on a data center access switch. The switch has IP Source Guard enabled on the client-facing ports. Which condition must be met for IP Source Guard to work properly?

Accepted Answer

DHCP snooping must be enabled on the VLAN and the port must be untrusted.. IP Source Guard uses a binding table created by DHCP snooping to validate the source IP address of packets received on a port. For IP Source Guard to work, DHCP snooping must be enabled on the VLAN, and the client-facing port must be configured as an untrusted port so that DHCP snooping can populate the binding table with valid DHCP lease information. Without this binding table, IP Source Guard has no source IP-to-MAC mapping to enforce.

Answer

DHCP snooping must be disabled on the VLAN.

Answer

All clients must use DHCP; static IPs are not supported.

Answer

Dynamic ARP Inspection must be enabled first.

Question 15

Which control plane protection mechanism should be configured to limit the rate of BGP updates destined to the CPU of a Nexus 9000 switch to prevent CPU overload?

Accepted Answer

Control Plane Policing (CoPP). Control Plane Policing (CoPP) is the correct mechanism because it directly filters and rate-limits control plane traffic, such as BGP updates, before it reaches the CPU of a Nexus 9000 switch. By applying a CoPP policy, you can protect the CPU from being overwhelmed by excessive BGP updates, ensuring stability and preventing denial-of-service conditions.

Answer

VLAN Access Control Lists (VACLs)

Answer

EtherChannel load balancing

Answer

Switched Port Analyzer (SPAN)