Chapter 26 IP Source Guard
The following table describes the labels in this screen.
Table 78 DHCP Snooping Port Configure
LABEL | DESCRIPTION |
Port | This field displays the port number. If you configure the * port, |
| the settings are applied to all of the ports. |
|
|
Server Trusted state | Select whether this port is a trusted port (Trusted) or an |
| untrusted port (Untrusted). |
| Trusted ports are connected to DHCP servers or other switches, |
| and the Switch discards DHCP packets from trusted ports only if |
| the rate at which DHCP packets arrive is too high. |
| Untrusted ports are connected to subscribers, and the Switch |
| discards DHCP packets from untrusted ports in the following |
| situations: |
| • The packet is a DHCP server packet (for example, OFFER, ACK, |
| or NACK). |
| • The source MAC address and source IP address in the packet |
| do not match any of the current bindings. |
| • The packet is a RELEASE or DECLINE packet, and the source |
| MAC address and source port do not match any of the current |
| bindings. |
| • The rate at which DHCP packets arrive is too high. |
|
|
Rate (pps) | Specify the maximum number for DHCP packets |
| the Switch receives from each port each second. The Switch |
| discards any additional DHCP packets. Enter 0 to disable this |
| limit, which is recommended for trusted ports. |
|
|
Apply | Click Apply to save your changes to the Switch’s |
| memory. The Switch loses these changes if it is turned off or loses |
| power, so use the Save link on the top navigation panel to save |
| your changes to the |
| configuring. |
|
|
Cancel | Click this to reset the values in this screen to their |
| values. |
|
|
26.5.2 DHCP Snooping VLAN Configure
Use this screen to enable DHCP snooping on each VLAN and to specify whether or not the Switch adds DHCP relay agent option 82 information (Chapter 32 on page 287) to DHCP requests that the Switch relays to a DHCP server for each VLAN. To
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