Configuring Vlan Router Ports; Defining An Ip Router Port; Configuring Vlan Router Ports" On Page - Alcatel OmniSwitch 6624 Network Configuration Manual

Configuring VLANs

Configuring VLAN Router Ports

Network device traffic is bridged (switched) at the Layer 2 level between ports that are assigned to the
same VLAN. However, if a device needs to communicate with another device that belongs to a different
VLAN, then Layer 3 routing is necessary to transmit traffic between the VLANs. Bridging makes the
decision on where to forward packets based on the packet's destination MAC address; routing makes the
decision on where to forward packets based on the packet's IP network address (e.g., IP - 21.0.0.10). For
more information about routing, see
A VLAN is available for routing traffic when a virtual router port is defined for that VLAN and at least
one active port has joined the VLAN. If a VLAN does not have a router port, its ports are in essence fire-
walled from other VLANs. Each VLAN supports one IP virtual router port and a maximum of 4094 IP
router port VLANs are allowed per stack.

Defining an IP Router Port

Use the vlan router ip
following when using this command:
1 The VLAN ID of the router port VLAN (can only specify an existing VLAN).
2 An IP address to assign to the router port (e.g., 193.204.173.21).
3
A subnet mask (defaults to the IP address class).
4
The router port forwarding status (defaults to forwarding). A forwarding router port sends IP frames to
other subnets. A router port that is not forwarding can receive frames from other hosts on the same subnet.
5
An Ethernet-II or SNAP router port encapsulation (defaults to Ethernet-II). The encapsulation deter-
mines the framing type the router port uses when generating frames that are forwarded out VLAN ports.
Select an encapsulation that matches the encapsulation of the majority of VLAN traffic.
The following vlan router ip command example assigns IP network address 21.0.0.1 to a VLAN 455
router port with a Class A subnet mask, forwarding status, and Ethernet-II encapsulation:
-> vlan 455 router ip 21.0.0.1 mask 255.0.0.0 forward e2
Specifying a subnet class, forwarding status, and encapsulation is optional, so it is not necessary to enter
these parameters as part of the command to accept their default values. For example, either one of the
following commands will create an IP router port for VLAN 955 with a class A subnet mask, forwarding
status and Ethernet-II encapsulation:
-> vlan 955 router ip 71.0.0.1 mask 255.0.0.0 forward e2
-> vlan 955 router ip 71.0.0.1
To remove an IP router port from a VLAN, use the no form of the vlan router ip command.
-> vlan 955 no router ip
To view a list of VLAN IP router ports configured on the switch, use the
For more information about this command, see the OmniSwitch CLI Reference Guide.
OmniSwitch 6624/6648 Network Configuration Guide
Chapter 12, "Configuring IP."
command to define an IP virtual router port for an existing VLAN. Specify the
show vlan router ip
April 2004
Configuring VLAN Router Ports
command.
page 4-11