DHCP S
NOOPING
C
OMMANDS
22-15
•
unit
- Stack unit. (Range: 1)
•
port
- Port number. (Range: 1-28)
•
lease-time
- The time after which an entry is removed from the table.
(Range: 0-4294967295, where 0 indicates a permanent entry)
Default Setting
None
Command Mode
Global Configuration
Command Usage
• If DHCP snooping is enabled globally, and also enabled on the VLAN
where the DHCP packet is received on a trusted port, a dynamic
DHCP snooping entry is added to the binding table. An entry is added
or removed dynamically whenever a client has gotten or released an IP
address from a DHCP server.
• Table entries can also be statically configured using the
ip dhcp
binding
command. Table entries includes a MAC address, IP address,
lease time, entry type (Dynamic-DHCP-Binding,
Static-DHCP-Binding), VLAN identifier, and port identifier.
• If the DHCP snooping is disabled globally, all dynamic bindings are
removed from the binding table; all static bindings are retained in the
binding table but will have no effect until DHCP snooping is globally
re-enabled.
• If DHCP snooping is enabled globally, and then disabled on a VLAN,
all dynamic bindings learned for this VLAN are removed from the
binding table; all static bindings configured for this VLAN are retained
in the binding table but will have no effect until snooping is re-enabled
on the VLAN.
• A static DHCP snooping entry can be added in the binding table under
any of the following conditions:
- If there is no binding with same VLAN ID and MAC address.
- If there is a binding with same VLAN ID and MAC address, and the
entry type is static IP source guard binding, static DHCP snooping
binding, or dynamic DHCP snooping binding, the new entry will
replace the old one.
Summary of Contents for 7824M/FSW - annexe 1
Page 2: ......
Page 24: ...TABLE OF CONTENTS xxiv ...
Page 28: ...TABLES xxviii ...
Page 32: ...FIGURES xxxii Figure 16 3 DNS Cache 16 7 ...
Page 34: ...GETTING STARTED ...
Page 46: ...SYSTEM DEFAULTS 1 12 ...
Page 62: ...SWITCH MANAGEMENT ...
Page 74: ...CONFIGURING THE SWITCH 3 12 ...
Page 112: ...BASIC MANAGEMENT TASKS 4 38 ...
Page 168: ...USER AUTHENTICATION 6 30 ...
Page 223: ...SHOWING PORT STATISTICS 9 33 Figure 9 12 Port Statistics ...
Page 230: ...ADDRESS TABLE SETTINGS 10 6 ...
Page 304: ...CLASS OF SERVICE 13 16 ...
Page 316: ...QUALITY OF SERVICE 14 12 ...
Page 338: ...MULTICAST FILTERING 15 22 ...
Page 346: ...DOMAIN NAME SERVICE 16 8 ...
Page 348: ...COMMAND LINE INTERFACE IP Interface Commands 35 1 ...
Page 362: ...OVERVIEW OF COMMAND LINE INTERFACE 17 14 ...
Page 494: ...USER AUTHENTICATION COMMANDS 21 48 ...
Page 514: ...CLIENT SECURITY COMMANDS 22 20 ...
Page 540: ...ACCESS CONTROL LIST COMMANDS 23 26 ...
Page 558: ...INTERFACE COMMANDS 24 18 ...
Page 576: ...MIRROR PORT COMMANDS 26 4 ...
Page 582: ...RATE LIMIT COMMANDS 27 6 ...
Page 616: ...SPANNING TREE COMMANDS 29 28 ...
Page 644: ...VLAN COMMANDS 30 28 ...
Page 664: ...CLASS OF SERVICE COMMANDS 31 20 ...
Page 678: ...QUALITY OF SERVICE COMMANDS 32 14 ...
Page 720: ...APPENDICES ...
Page 726: ...SOFTWARE SPECIFICATIONS A 6 ...
Page 730: ...TROUBLESHOOTING B 4 ...
Page 746: ...INDEX Index 6 ...
Page 747: ......