When DHCP snooping is enabled on a VLAN, the switch acts as a layer 2 firewall between untrusted hosts and valid DHCP servers. Client-facing ports are designated as untrusted, while ports connected to legitimate DHCP servers must be designated as trusted. When an untrusted port receives a DHCP broadcast (such as a DISCOVER message) from a client, the switch intercepts the packet and forwards it exclusively to the configured trusted ports. Because the Linux-Server is acting as the DHCP server, its connected switch port (port4) must be trusted. If port4 is left untrusted, the switch will not forward the client's DHCP broadcasts to it, resulting in the server receiving no DHCP traffic.

A. The scenario explicitly states this is intra-VLAN traffic and tcpdump confirms broadcasts, indicating the client is successfully broadcasting on the established Student VLAN.

B. Port1 connects to the Linux-Client, so it must remain untrusted. An untrusted client port successfully accepts DHCP discovery broadcasts to forward to trusted ports.

D. The FortiSwitch port table demonstrates that the Native VLAN on port1 is already configured as "Student," meaning untagged traffic is natively placed on this VLAN.

Fortinet Document Library: FortiSwitchOS 7.2 Administration Guide. "Layer 2 Security: DHCP Snooping." (Details the default untrusted state of ports and the requirement to configure trusted ports for DHCP servers to receive forwarded requests).

Fortinet Knowledge Base (Technical Note): "Technical Tip: How to configure DHCP snooping." (Confirms that DHCP DISCOVER packets received on an untrusted port are only forwarded to trusted ports).

IEEE/IETF RFC Documentation: IETF RFC 3046 "DHCP Relay Agent Information Option" / Core DHCP Snooping Principles. (Outlines the fundamental mechanism of trusted versus untrusted network segments for DHCP traffic handling).