IP ServicesDifficulty 3/5
Clients on VLAN 20 cannot get addresses from a DHCP server on another subnet. Which configuration on the VLAN 20 router interface fixes this?
- Aip ospf network broadcast
- Bip dhcp excluded-address
- Cip helper-address <server-ip>
- Dip nat inside
Show answer and rationale
Correct: C. DHCP Discover is a broadcast that routers do not forward. 'ip helper-address' on the interface facing the clients relays the broadcast as unicast to the server (DHCP relay agent).
- B — Excluded-address applies to a router acting as the DHCP server.
- D — NAT does not relay broadcasts.
- A — OSPF network type is unrelated.