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CCNA lab 15

DHCP server on a router, with a relay for a remote LAN

Make R1 the DHCP server for two LANs, keep the first ten addresses out of each pool, and relay requests from the remote LAN with ip helper-address.

About 25 minutes 7 devices 3 tasksIntermediate

Scenario

PC1 and PC2 on LAN 10 (192.168.10.0/24, behind R1) and PC3 on LAN 20 (192.168.20.0/24, behind R2) are set to get their addresses by DHCP, but nothing answers yet. Make R1 the DHCP server for both LANs: .1 to .10 in each subnet are reserved for network devices, and each LAN's gateway is its router's .1 address. DHCP requests are broadcasts and do not cross R2 on their own, so R2 must relay them to R1 (10.0.12.1).

eth0Fa0/1eth0Fa0/2Gi0/1Gi0/0Gi0/1Gi0/0/0Gi0/0/1Gi0/1Fa0/1eth0PC1PC1 — PCPC2PC2 — PCSW1SW1 — Switch (Catalyst 2960-24)R1R1 — Router (2911)R2R2 — Router (ISR 4321)SW2SW2 — Switch (Catalyst 2960-24)PC3PC3 — PC

Your tasks

  1. A DHCP client on LAN 10 gets an address from 192.168.10.11 up, with gateway 192.168.10.1.
  2. A DHCP client on LAN 20 gets an address from 192.168.20.11 up, with gateway 192.168.20.1.
  3. PC1 and PC3 hold DHCP leases (run ipconfig /renew on each) and PC3 can ping PC1.

The lab checks the result, not the exact commands. For example, a ping task passes only when the ping really succeeds through the network you built.

Start the lab