Avaya P334T-ML - Manual (Page 137)

Chapter 12 Avaya P330 Layer 3 Features
Avaya P334T-ML User’s Guide 121
Routing Configuration
Forwarding
The P330 forwards IP packets between IP networks. When it receives an IP packet
through one of its interfaces, it forwards the packet through one of its interfaces. The
P330 supports multinetting, enabling it to forward packets between IP subnets on
the same VLAN as well as between different VLANs. Forwarding is performed
through standard means in Router mode.
Multinetting (Multiple Subnets per VLAN)
In Router Mode, most applications such as RIP and OSPF, operate per IP interface.
Other applications such as VRRP and DHCP/BOOTP Relay operate per VLAN.
Configuration of these applications is done in the Interface mode. When there is
only a single interface (subnet) per VLAN then system behavior is intuitive since a
subnet and a VLAN are the same.
Multiple interfaces (subnets) per VLAN are more complicated. For example, if there
are two interfaces over the same VLAN and you configure DHCP server on one
interface, it will be used also for the second interface over the same VLAN. This
behavior might be less expected and in some cases wrong.
In order to prevent misconfiguration and unexpected results, the P330 prevents
configuration of VLAN-oriented commands on an interface unless explicitly
requested by the user via the “enable vlan commands” CLI command.
Configuring the “enable vlan commands” on one interface defeats this option on
other interfaces that belong to the same VLAN. This ensures that VLAN-oriented
commands can be configured from one interface only.
In case there is only one interface over a VLAN, then VLAN oriented commands for
this VLAN can be configured through the single interface without using the “enable
vlan commands” command.
L VLAN-oriented commands that were configured affect the VLAN of the
interface that was used at the time the command was issued.
L If the interface is moved to another VLAN (using the “ip vlan command”)
VLAN oriented configuration still relates to the original VLAN.