Alcatel OmniSwitch 6800 Series Network Configuration Manual page 137

Defining VLAN Rules
When a mobile port receives a DHCP frame that matches a DHCP rule, the port is temporarily assigned to
the VLAN long enough to forward the DHCP requests within the VLAN broadcast domain. The source
MAC address of the DHCP frame, however, is not learned for that VLAN port association. As a result, the
show mac-address-table
The show vlan port
ciation that occurs during this process.
Once a device connected to a mobile port receives an IP address from the DHCP server, the VLAN port
assignment triggered by the device's DHCP frames matching a VLAN DHCP rule is dropped unless regu-
lar port traffic matches another rule on that same VLAN. If this match occurs, or the traffic matches a rule
on another VLAN, then the source MAC address of the mobile port's frames is learned for that VLAN
port association.
DHCP rules are most often used in combination with IP network address rules. A DHCP client has an IP
address of all zeros (0.0.0.0) until it receives an IP address from a DHCP server, so initially it would not
match any IP network address rules.
Binding rules, MAC address rules, and protocol rules also capture DHCP client traffic. The exception to
this is binding rules that specify an IP address as part of the rule, similar to IP network address rule defini-
tions.
The following DHCP rule types are available:
DHCP MAC Address
•
DHCP MAC Range
•
DHCP Port
•
DHCP Generic
•
OmniSwitch 6800 Series Network Configuration Guide
command output will not contain an entry for the DHCP source MAC address.
command output, however, will contain an entry for the temporary VLAN port asso-
November 2004
VLAN Rules Overview
page 7-5