Troubleshooting
Display the DHCPv4 commands configured on the router
This command output displays the DHCPv4 commands configured on R1.
R1# show running-config | section dhcp ip dhcp excluded-address 192.168.10.1 192.168.10.9 ip dhcp excluded-address 192.168.10.254 ip dhcp pool LAN-POOL-1 network 192.168.10.0 255.255.255.0 default-router 192.168.10.1 dns-server 192.168.11.5 domain-name example.com
The | section parameter displays only the commands associated with DHCPv4 configuration.
Display a list of all IPv4 address to MAC address bindings provided by the DHCPv4 service
This command displays a list of all IPv4 address to MAC address bindings that have been provided by the DHCPv4 service.
R1# show ip dhcp binding
Bindings from all pools not associated with VRF:
IP address. Client-ID/ Lease expiration Type State Interface
Hardware address/
User name
192.168.10.10. 0100.5056.b3ed.d8. Sep 15 2019 8:42 AM Automatic Active GigabitEthernet0/0/0
Display count information regarding the number of DHCPv4 messages that have been sent and received
This command is used to verify that messages are being received or sent by the router. This command displays count information regarding the number of DHCPv4 messages that have been sent and received.
R1# show ip dhcp server statistics Memory usage 19465 Address pools 1 Database agents 0 Automatic bindings 2 Manual bindings 0 Expired bindings 0 Malformed messages 0 Secure arp entries 0 Renew messages 0 Workspace timeouts 0 Static routes 0 Relay bindings 0 Relay bindings active 0 Relay bindings terminated 0 Relay bindings selecting 0 Message Received BOOTREQUEST 0 DHCPDISCOVER 4 DHCPREQUEST 2 DHCPDECLINE 0 DHCPRELEASE 0 DHCPINFORM 0
Confirm if helper address is assigned (Relay)
When a Router has been configured as a DHCPv4 relay agent, it accepts broadcast requests for the DHCPv4 service and then forwards those requests as a unicast to the IPv4 address. The network administrator can use the following command to verify the configuration.
R1# show ip interface g0/0/0 GigabitEthernet0/0/0 is up, line protocol is up Internet address is 192.168.10.1/24 Broadcast address is 255.255.255.255 Address determined by setup command MTU is 1500 bytes Helper address is 192.168.11.6 (output omitted)
Confirming a DHCP Client Interface
Command to confirm that an interface was set to obtain an IP Address via DHCPv4
R1# show ip interface g0/0/1 GigabitEthernet0/0/1 is up, line protocol is up Internet address is 209.165.201.12/27 Broadcast address is 255.255.255.255 Address determined by DHCP (output omitted)