Which of the following configurations correctly sets up a DHCP server for 192.168.20.0/24 with pool 192.168.20.50-192.168.20.150 and gateway 192.168.20.1?

• A. /ip pool add name=dhcp_pool ranges=192.168.20.50-192.168.20.150; /ip dhcp-server add name=dhcp1 interface=bridge2 address-pool=dhcp_pool gateway=192.168.20.1; /ip dhcp-server network add address=192.168.20.0/24 gateway=192.168.20.1
• B. /ip pool add name=dhcp_pool ranges=192.168.20.50-192.168.20.150; /ip dhcp-server add name=dhcp1 interface=bridge1 address-pool=dhcp_pool gateway=192.168.20.1; /ip dhcp-server network add address=192.168.20.0/24 gateway=192.168.20.1
• C. /ip pool add name=dhcp_pool ranges=192.168.20.60-192.168.20.160; /ip dhcp-server add name=dhcp1 interface=bridge2 address-pool=dhcp_pool gateway=192.168.20.2; /ip dhcp-server network add address=192.168.20.0/24 gateway=192.168.20.2
• D. /ip pool add name=dhcp_pool ranges=192.168.20.50-192.168.20.150; /ip dhcp-server add name=dhcp1 interface=bridge2 address-pool=dhcp_pool gateway=192.168.20.1; /ip dhcp-server network add address=192.168.20.0/24 gateway=192.168.20.1

Answer: (A)

When a DHCP server serves a specific LAN, the pool of addresses, the interface it runs on, and the default gateway it advertises all need to line up with the actual network you’re serving. For 192.168.20.0/24, you want clients to get addresses from 192.168.20.50 through 192.168.20.150, and you want the router to be the gateway at 192.168.20.1. The DHCP server must run on the interface that connects to that LAN (so it can talk to clients on that segment) and you must define the network so clients know which gateway to use.

The correct setup creates the address pool 192.168.20.50–192.168.20.150, runs the DHCP server on the interface connected to the 192.168.20.0/24 network (with the pool attached), and sets the gateway to 192.168.20.1. It also defines the network 192.168.20.0/24 with that same gateway so the DHCP option for the default router is consistently advertised to clients.

If the interface is wrong (not on the 192.168.20.0/24 segment) or the pool lies outside the subnet, or the gateway differs (for example, using 192.168.20.2 or another subnet boundary), the DHCP server won’t provide valid default routes or could hand out addresses that don’t reach the LAN. The configuration that aligns the pool, gateway, and interface with 192.168.20.0/24 is the correct one.