Dell C1048P Port Extender Networking Configuration Guide for the C9000 Series - Page 341
Drop DHCP Packets on Snooped VLANs Only, Displaying the Contents of the Binding Table
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Displaying the Contents of the Binding Table To display the contents of the binding table, use the following command. • Display the contents of the binding table. EXEC Privilege mode show ip dhcp snooping Example of the show ip dhcp snooping Command View the DHCP snooping statistics with the show ip dhcp snooping command. Dell#show ip dhcp snooping IP DHCP Snooping IP DHCP Snooping Mac Verification IP DHCP Relay Information-option IP DHCP Relay Trust Downstream Database write-delay (In minutes) DHCP packets information Relay Information-option packets Relay Trust downstream packets Snooping packets Packets received on snooping disabled L3 Ports Snooping packets processed on L2 vlans DHCP Binding File Details Invalid File Invalid Binding Entry Binding Entry lease expired List of Trust Ports List of DHCP Snooping Enabled Vlans List of DAI Trust ports : Enabled. : Disabled. : Disabled. : Disabled. : 0 : 0 : 0 : 0 : 0 : 142 : 0 : 0 : 0 :Te 0/49 :Vl 10 :Te 0/49 Drop DHCP Packets on Snooped VLANs Only Binding table entries are deleted when a lease expires or the relay agent encounters a DHCPRELEASE. Line cards maintain a list of snooped VLANs. When the binding table fills, DHCP packets are dropped only on snooped VLANs, while such packets are forwarded across non-snooped VLANs. Because DHCP packets are dropped, no new IP address assignments are made. However, DHCP release and decline packets are allowed so that the DHCP snooping table can decrease in size. After the table usage falls below the maximum limit of 4000 entries, new IP address assignments are allowed. To view the number of entries in the table, use the show ip dhcp snooping binding command. This output displays the snooping binding table created using the ACK packets from the trusted port. Dell#show ip dhcp snooping binding Codes : S - Static D - Dynamic IP Address MAC Address Expires(Sec) Type VLAN Interface 10.1.1.251 00:00:4d:57:f2:50 172800 D Vl 10 Te 0/2 10.1.1.252 00:00:4d:57:e6:f6 172800 D Vl 10 Te 0/1 10.1.1.253 00:00:4d:57:f8:e8 172740 D Vl 10 Te 0/3 10.1.1.254 00:00:4d:69:e8:f2 172740 D Vl 10 Te 0/50 Total number of Entries in the table : 4 Dynamic Host Configuration Protocol (DHCP) 341
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