3Com Switch 7750 Configuration Guide

DHCP Snooping Configuration 631
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■ If you configure a remote ID sub-option in both system view and on a port, the
remote ID sub-option configured on the port applies when the port receives a
packet, and the global remote ID applies to other interfaces that have no
remote ID sub-option configured.
■ If you have configured a remote ID with the vlan vlan-id argument specified,
and the other one without the argument in Ethernet port view, the former
remote ID applies to the DHCP messages from the specified VLAN, while the
latter one applies to DHCP messages from other VLANs.
■ In a port aggregation group, you can use this command to configure the
primary and member ports respectively. When Option 82 is added, however,
the remote ID is subject to the one configured on the primary port.
■ The remote ID configured on a port will neither be synchronized in the case of
port aggregation.
Configuring the padding format for Option 82
Configuring IP Filtering
Table 503 Configure the remote ID sub-option in Option 82
Operation Command Description
Enter system view system-view -
Configure the remote ID
sub-option in system view
dhcp-snooping information
remote-id { sysname |
string string }
Optional
By default, the remote ID
sub-option is the MAC
address of the DHCP
snooping device that received
the DHCP client’s request.
Enter Ethernet port view interface interface-type
interface-number
-
Configure the remote ID
sub-option in Ethernet port
view
dhcp-snooping information
[ vlan vlan-id ] remote-id
string string
Optional
By default, the remote ID
sub-option is the MAC
address of the DHCP
snooping device that received
the client’s request.
Table 504 Configure the padding format for Option 82
Operation Command Description
Enter system view system-view -
Configure the padding format dhcp-snooping information
packet-format { extended |
standard }
Optional
By default, the padding
format is in extended format.
Table 505 Configure IP filtering
Operation Command Description
Enter system view system-view -
Enter Ethernet port view interface interface-type
interface-number
-
Enable IP filtering ip check source ip-address
[ mac-address ]
Required
By default, this function is
disabled.