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Dell PowerConnect 55xx Systems User Guide
FILE LOCATION: C:\Users\gina\Desktop\Checkout_new\Maintenance Projects\Dell
Contax\sources\CxUGSwitching_DHCP.fm
D E LL C O N F ID E N T IA L – P R E L I M I N A RY 1 0 / 3 0/ 1 3 - F O R P R O O F O N LY
As shown in Table 19-1, the DHCP Snooping Binding database is updated by
interception of DHCPACK, DHCPDECLINE and DHCPRELEASE packets,
and is stored in non-volatile memory.
Even if a port is down, its entries are not deleted.
NOTE:
Only DHCP requests on untrusted ports are maintained in the Binding
database.
Limitations
The following limitations apply:
• Enabling DHCP snooping uses TCAM resources.
• The switch writes changes to the binding database only when the switch
system clock is synchronized with SNTP.
• The switch does not update the Binding database when a station moves to
another interface.
Global Parameters
Use the
Global Parameters
page to:
• Enable/disable DHCP snooping globally.
• Determine whether to forward or filter DHCP packets received from
untrusted interfaces, whose source MAC address and the DHCP client
MAC address do not match.
• Determine whether to forward or filter DHCP packets, received from
untrusted interfaces, with option-82 information.
• Set Binding database update interval.