Rapid PVST+ (Per-VLAN Rapid Spanning Tree) is the Cisco enhancement of RSTP (802.1w) that provides per-VLAN rapid convergence, typically in under one second. It’s the recommended mode for modern Cisco campus designs as it allows the blocking link to transition to forwarding state almost immediately upon a topology change, making optimal use of available bandwidth like the 40Gbps core link. MSTP is for mapping multiple VLANs to a single instance, and classic STP/PVST+ have much slower convergence times.

Since the SVI is up (pingable from its own switch) but hosts cannot reach it, the issue is likely that VLAN 20 is not being transported across the trunk link from the access to the distribution layer. The first logical step is to verify the trunk configuration on both ends to ensure VLAN 20 is in the allowed list and is not pruned. Checking the user’s PC or the routing table addresses layer 3, which is not the indicated problem, and rebooting is not an efficient troubleshooting step.

In Cisco SD-Access fabric, the Edge Node (typically a Catalyst switch running the fabric edge role) is the point where endpoints connect. Its key function is to act as a VXLAN Tunnel Endpoint (VTEP), encapsulating incoming traditional Ethernet/IP frames into VXLAN packets for transport across the fabric and decapsulating them when traffic exits towards the endpoint. The Control Plane Node manages endpoint identity and location, the Border Node connects the fabric to external networks, and ‘Intermediate Node’ is not a standard SD-Access role.

True Out-of-Band (OOB) management provides access to network devices through a dedicated, physically separate network infrastructure (separate NICs, cables, and switches). This ensures management remains available even if the primary production network or data interfaces fail. Using a separate VLAN or VRF is considered in-band management, as it shares the same physical infrastructure. SSH via the production SVI is standard in-band management.

“802.1X with Open Authentication” is a mixed authentication mode supported on Cisco WLCs. In this setup, the wireless network advertises support for both 802.1X (for corporate users) and open authentication. Clients attempting 802.1X (like corporate laptops with certificates) will use that method. Clients that do not support or fail 802.1X (like guests) will be redirected to the open authentication path, which can then trigger a web authentication (captive portal) policy. The other options do not support this dual, conditional authentication method on a single SSID.

In a collapsed core design, the core/distribution layer switches take on the combined functions of both layers. Their primary role is to perform high-speed, inter-VLAN routing (Layer 3) between different access layer blocks (wiring closets) and to provide connectivity to centralized resources like data center, Internet edge, and WAN. They are not just Layer 2 aggregators; they are the routing backbone of the campus.

FHRPs like HSRP (Hot Standby Router Protocol) are designed to solve the problem of a single point of failure at the access layer’s default gateway. They allow multiple physical routers to share a single virtual IP and MAC address. End hosts are configured with this virtual IP as their gateway. If the active router fails, the standby router takes over the virtual address, providing transparent failover for the hosts without requiring any changes on the endpoints.

For a VLAN to traverse a trunk link, it must be explicitly included in the allowed VLAN list on both ends of the trunk. The ‘show interface trunk’ command displays this list. While the encapsulation type and trunk status are important for establishing the trunk, and the native VLAN must match for security and proper operation, the absence of a required VLAN from the allowed list is a common cause of connectivity issues. This is the most direct piece of information to check for that specific purpose.

In a typical Cisco IP phone deployment with a connected PC, the switchport is an access port that carries two VLANs: an access VLAN (for the data traffic to/from the PC) and a voice VLAN (for the phone’s traffic). The command ‘switchport voice vlan 110’ only sets the voice VLAN. If the ‘switchport access vlan X’ command is missing or set to a VLAN with no DHCP service, the PC will not receive an IP address. The phone works because it uses VLAN 110. The other options are less likely initial causes.

Rapid PVST+ (Per-VLAN Rapid Spanning Tree) is the Cisco enhancement of RSTP (802.1w) that provides per-VLAN rapid convergence, typically in under one second. It’s the recommended mode for modern Cisco campus designs as it allows the blocking link to transition to forwarding state almost immediately upon a topology change, making optimal use of available bandwidth like the 40Gbps core link. MSTP is for mapping multiple VLANs to a single instance, and classic STP/PVST+ have much slower convergence times.0