Which action may help fix DHCP issues on a pair of Aruba CX switches with APs connected to VLAN 1000?

Which action may help fix DHCP issues on a pair of Aruba CX switches with APs connected to VLAN 1000?

• A. Enter the VSX primary switch commands: vsx, vsx-sync dhcp-relay, exit
• B. Enter vlan 1000 and ip relay-address 10.200.1.100
• C. Add an SVI in the 10.102.39.0/24 subnet on the Aruba CX 6100 switch that the APs are connected to
• D. On the Aruba CX 6100 switch, configure interface vlan 1000 and set ip helper-address 10.200.1.1

Answer: (C)

DHCP relay needs a Layer 3 interface on the switch for the VLAN that the clients (APs) are in. Without an SVI for that VLAN, the switch has no local gateway or routing presence to forward DHCP requests to a DHCP server, so clients can’t obtain an IP. Adding a switched virtual interface for the subnet 10.102.39.0/24 on the Aruba CX 6100 that the APs are connected to gives the switch a proper L3 endpoint in that VLAN. With this SVI in place, the switch can route DHCP Discover messages toward the DHCP server (and you can configure the relay to the server’s IP on that SVI). This creates the necessary path for DHCP traffic and is a common first step to fix DHCP issues in VLAN-based deployments. The other options either reference commands that aren’t applicable in this context or rely on relay settings without a corresponding L3 interface in the APs’ VLAN, which would not be effective until the SVI exists.

DHCP relay needs a Layer 3 interface on the switch for the VLAN that the clients (APs) are in. Without an SVI for that VLAN, the switch has no local gateway or routing presence to forward DHCP requests to a DHCP server, so clients can’t obtain an IP.

Adding a switched virtual interface for the subnet 10.102.39.0/24 on the Aruba CX 6100 that the APs are connected to gives the switch a proper L3 endpoint in that VLAN. With this SVI in place, the switch can route DHCP Discover messages toward the DHCP server (and you can configure the relay to the server’s IP on that SVI). This creates the necessary path for DHCP traffic and is a common first step to fix DHCP issues in VLAN-based deployments.

The other options either reference commands that aren’t applicable in this context or rely on relay settings without a corresponding L3 interface in the APs’ VLAN, which would not be effective until the SVI exists.