Verifying Dynamic DHCP Options for a Router

You can identify dynamically obtained DHCP options for a router.
  1. On a router enter the show running-config command. Examine the output to identify dynamically obtained options. These options have a “dynamic” tag appended to them in the running configuration.
    device> show running-config
    
    Current configuration:
    !
    ver 08.0.61b1T213
    ...
    !
    !
    vlan 1 name DEFAULT-VLAN by port
    !
    !
    !
    hostname TestHostName dynamic
    ip dns domain-list ManualDomain.com
    ip dns domain-list testDomain.com dynamic
    ip dns domain-list testStaticDomain.com
    ip dns server-address 20.20.20.8 20.20.20.9 10.10.10.5(dynamic) 20.20.20.5
    ip route 0.0.0.0/0 10.10.10.1 distance 254 dynamic
    !
    !
    interface ethernet 1/1/7
     ip address 10.10.10.2 255.255.255.0 dynamic
    !
    interface ethernet 1/1/21
     disable                                                          
    !
    interface ethernet 1/2/2
     speed-duplex 1000-full
    !
    interface ethernet 1/2/4
     speed-duplex 1000-full
    !
    interface ethernet 1/2/5
     speed-duplex 1000-full
    !
    interface ethernet 1/2/6
     speed-duplex 1000-full
    !
    interface ethernet 1/2/7
     speed-duplex 1000-full
    !
    interface ethernet 1/2/8
     speed-duplex 1000-full
    !
    !                                                                 
    lldp run
    !
    !
    end
    
  2. On a router enter the show configuration command. Examine the output to identify dynamically obtained options. These options have a “dynamic” tag appended to them in the running configuration.
    device> show configuration
    
    !
    Startup-config data location is flash memory
    !
    Startup configuration:
    !
    ver 08.0.61b1T213
    !
    stack unit 1
     ...
    !
    !
    vlan 1 name DEFAULT-VLAN by port
    !
    !
    !
    ip dns domain-list ManualDomain.com
    ip dns domain-list testStaticDomain.com
    ip dns server-address 20.20.20.8 20.20.20.9 20.20.20.5
    ip route 0.0.0.0/0 10.10.10.1 distance 254 dynamic
    !
    !
    !
    interface ethernet 1/1/7
     ip address 10.10.10.2 255.255.255.0 dynamic
    !
    interface ethernet 1/1/21                                         
     disable
    !
    interface ethernet 1/2/2
     speed-duplex 1000-full
    !
    interface ethernet 1/2/4
     speed-duplex 1000-full
    !
    interface ethernet 1/2/5
     speed-duplex 1000-full
    !
    interface ethernet 1/2/6
     speed-duplex 1000-full
    !
    interface ethernet 1/2/7
     speed-duplex 1000-full
    !
    interface ethernet 1/2/8
     speed-duplex 1000-full
    !                                                              
    !
    lldp run
    !
    !
    end