clear dhcp-snooping binding

Syntax

clear dhcp-snooping binding [all | ip <IP-ADDR> | port <PORT-NUM> | vlan <VLAN-ID>]
      

Description

Clear all DHCP snooping binding entries or the binding entries on the specified IP address, port, or VLAN.

Parameters

binding

Clear all the DHCP snooping binding entries as specified by the options.

all

Clear all the DHCP snooping binding entries.

IP <IP-ADDR>

Clear the DHCP snooping binding entry on the specified IP address.

port <PORT-NUM>

Clear the DHCP snooping binding entries on the specified port by entering the port number.

vlan <VLAN-ID>

Clear the DHCP snooping binding entries on the specified VLAN by entering the VLAN identifier.

Usage

clear dhcp-snooping binding all
clear dhcp-snooping binding ip <IP-ADDR>r
      
clear dhcp-snooping binding VLAN <VLAN-ID>r
      

Example

switch(config)# clear dhcp-snooping binding all
                    
Warning: Execution of this command results in clearing of dynamically learnt   
DHCP Snooping entries from the binding table on this switch. Since the         
DHCP Server and the DHCP Clients would not be aware of this change, this can   
have side effects.                                                             

Do you want to continue (y/n)? y

switch(config)# sh dhcp-snooping binding
  MacAddress    IP              VLAN Interface Time Left
  ------------- --------------- ---- --------- ---------
                                                    
                        
switch(config)# show log -r                 
 Keys:   W=Warning   I=Information
         M=Major     D=Debug E=Error
----  Reverse event Log listing: Events Since Boot  ----
W 12/12/16 14:27:03 05357 dhcp-snoop: AM1: All the dynamic binding entries were cleared.
I 12/12/16 14:23:24 03125 mgr: AM1: Startup configuration changed by CLI.  New seq. number 7

Example

switch(config)# clear dhcp-snooping binding all
                    
Warning: Execution of this command results in clearing of dynamically learnt   
DHCP Snooping entries from the binding table on this switch. Since the         
DHCP Server and the DHCP Clients would not be aware of this change, this can   
have side effects.                                                             

Do you want to continue (y/n)? y

switch(config)# sh dhcp-snooping binding 

  MacAddress    IP              VLAN Interface Time Left
  ------------- --------------- ---- --------- ---------
                                                        
switch(config)# show log -r                 
 Keys:   W=Warning   I=Information
         M=Major     D=Debug E=Error
----  Reverse event Log listing: Events Since Boot  ----
W 12/12/16 14:27:03 05357 dhcp-snoop: AM1: All the dynamic binding entries were cleared.
I 12/12/16 14:23:24 03125 mgr: AM1: Startup configuration changed by CLI. New seq. number 7
———————————————————————————————————————————————————————————————————————————————————————————————
switch(config)# show dhcp-snooping                                 

 DHCP Snooping Information

  DHCP Snooping              : Yes
  Enabled VLANs              : 20 40                                
  Verify MAC address         : Yes                                  
  Option 82 untrusted policy : drop                                 
  Option 82 insertion        : Yes                                  
  Option 82 remote-id        : mac                                  
  Store lease database       : Not configured                       

                  Max     Current Bindings
   Port  Trust  Bindings  Static   Dynamic
  -----  -----  --------  ----------------
    A1    Yes      -        -        -    
    A2    No       -        -        10   

  Ports A3-A24,B1-B24,C1-C24,F1-F24 are untrusted
———————————————————————————————————————————————————————————————————————————————————————————————

switch(config)# show dhcp-snooping binding 

  MacAddress    IP              VLAN Interface Time Left
  ------------- --------------- ---- --------- ---------
  000000-c97c83 192.168.101.21  20   A2        3579     
  000000-c97c84 192.168.101.30  20   A2        3582     
  000000-c97c85 192.168.101.28  20   A2        3579     
  000000-c97c86 192.168.101.25  20   A2        3577     
  000000-c97c87 192.168.101.23  20   A2        3574     
  000000-c97c88 192.168.101.26  20   A2        3579     
  000000-c97c89 192.168.101.24  20   A2        3580     
  000000-c97c8a 192.168.101.27  20   A2        3582     
  000000-c97c8b 192.168.101.29  20   A2        3577     
  000000-c97c8c 192.168.101.22  20   A2        3580     

———————————————————————————————————————————————————————————————————————————————————————————————

switch(config)# show dhcp-snooping binding

  MacAddress    IP              VLAN Interface Time Left
  ------------- --------------- ---- --------- ---------
                                                        
switch(config)# show log -r                 
 Keys:   W=Warning   I=Information
         M=Major     D=Debug E=Error
----  Reverse event Log listing: Events Since Boot  ----
W 12/12/16 14:32:28 05359 dhcp-snoop: AM1: Dynamic binding entries on the port A2 were cleared.
W 12/12/16 14:29:58 05360 dhcp-snoop: AM1: Dynamic binding entries on the VLAN 20 were cleared.
W 12/12/16 14:29:36 05360 dhcp-snoop: AM1: Dynamic binding entries on the VLAN 40 were cleared.
W 12/12/16 14:28:29 00861 dhcp-snoop: AM1: backplane: Ceasing bad release logs for 5m
W 12/12/16 14:28:29 00860 dhcp-snoop: AM1: backplane: Attempt to release address
            192.168.101.30 leased to port A2 detected on port A2
W 12/12/16 14:28:29 00860 dhcp-snoop: AM1: backplane: Attempt to release address
            192.168.101.21 leased to port A2 detected on port A2
W 12/12/16 14:27:03 05357 dhcp-snoop: AM1: All the dynamic binding entries were cleared.
I 12/12/16 14:23:24 03125 mgr: AM1: Startup configuration changed by CLI. New seq. number 7
W 12/12/16 14:22:53 00853 dhcp-snoop: AM1: backplane: Ceasing untrusted port
            destination logs for 5m
W 12/12/16 14:22:53 00852 dhcp-snoop: AM1: backplane: Client packet destined to
            untrusted port dropped