N10-009 Leak Questions

When a host fails to obtain an IP address from a DHCP server, it assigns itself an APIPA (Automatic Private IP Addressing) address in the 169.254.x.x range, commonly described as a “self-assigned IP.” This prevents communication outside the local link, including reaching the default gateway.

B. RFC1918 addresses are private ranges (10.x.x.x, 172.16–31.x.x, 192.168.x.x), but these are not self-assigned.

C. If the TCP/IP stack were disabled, the host wouldn’t have any IP at all.

D. If a static IP were assigned, it would show a configured value, not self-assigned.

References (CompTIA Network+ N10-009):

Domain: Network Troubleshooting — IP addressing issues, DHCP failures, APIPA behavior.

To enable communication between VLANs, the technician must configure inter-VLAN routing. On a Layer 3 switch, this is commonly done by creating an SVI (Switched Virtual Interface) for each VLAN. An SVI provides a virtual Layer 3 interface with an IP address that acts as the default gateway for hosts in that VLAN. Once SVIs exist and routing is enabled, the switch can route traffic between VLAN subnets internally, allowing clients in different VLANs to communicate (subject to any security controls). This aligns with Network+ (N10-009) infrastructure objectives covering VLANs, Layer 2/Layer 3 switching, and the requirement for routing to cross broadcast domains.

ACLs can permit or deny inter-VLAN traffic, but they do not create the routing function by themselves. VXLAN is an overlay tunneling technology used mainly in data centers to extend Layer 2 networks over Layer 3 fabrics, not the standard solution for basic VLAN-to-VLAN connectivity on a switch. VPC is not the required configuration element for inter-VLAN routing in this context. Therefore, configuring SVIs is the correct and most direct answer.

===========

When multiple redundant links exist between switches, Spanning Tree Protocol (STP) is required to prevent switching loops. STP blocks redundant paths but can allow aggregation if configured with protocols like LACP.

B. SVIs provide Layer 3 interfaces, not loop prevention.

C. Native VLAN defines the untagged VLAN but does not manage loops.

D. FHRP (VRRP, HSRP, GLBP) provides gateway redundancy, not switch uplink management.

References (CompTIA Network+ N10-009):

Domain: Network Infrastructure — STP, redundancy, loop prevention.

The correct answer is SAML (Security Assertion Markup Language). SAML is an XML-based standard used for single sign-on (SSO) and identity federation. It allows identity providers (IdPs) to share authentication and authorization data with service providers (SPs), passing secure tokens containing user attributes and credentials.

A. IAM (Identity and Access Management) is the broader framework, not specifically XML-based.

B. MFA enforces multiple factors for authentication but does not involve XML assertions.

C. RADIUS is an AAA protocol, but it uses UDP, not XML assertions.

SAML is widely used in federated identity systems, enabling secure authentication across different domains and applications without requiring multiple credentials.

References (CompTIA Network+ N10-009):

Domain: Network Security — Authentication methods, SAML, SSO.