Juniper Switch Routed VLAN Interface (RVI) L3 Interface

Why Should I Use an RVI?

In addition to providing communication between VLANs, an RVI binds specific VLANs to specific Layer 3 interfaces, allowing you to track RVI use for billing purposes. Configure an RVI for a VLAN if you need to:

• Allow traffic to be routed between VLANs.
• Provide Layer 3 IP connectivity to the switch.

Creating an RVI

• Configure VLANs—Virtual LANs are groups of hosts that communicate as if they were attached to the same broadcast stream. VLANs are created with software and do not require a physical router to forward traffic. VLANs are Layer 2 constructs.

• Create RVIs for the VLANs—The switch’s RVI uses Layer 3 logical interfaces on the switch (unlike routers, which can use either physical or logical interface).

• Assign an IP address to each VLAN—An RVI cannot be activated unless it is associated with a physical interface.

• Bind the VLANs to the logical interfaces—There is a one-to-one mapping between a VLAN and an RVI, so only one RVI can be mapped to a VLAN.

Please configure VLANs, Access and Trunk ports on switches according to diagram

We'll create and assign the following VLANs:

Create VLANs 10 and 20 learn Create VLANs.

set vlans MANAGEMENT vlan-id 10
set vlans ADMIN vlan-id 20
set vlans IT vlan-id 30
set vlans ACCOUNTS vlan-id 40

Create a logical layer 3 VLAN interface on SWITCH-1

set interfaces vlan unit 10 family inet address 10.1.10.1/24
set interfaces vlan unit 10 family inet address 10.1.20.1/24
set interfaces vlan unit 10 family inet address 10.1.30.1/24
set interfaces vlan unit 10 family inet address 10.1.40.1/24

Create a logical layer 3 VLAN interface on SWITCH-2 for management perpose.

set interfaces vlan unit 10 family inet address 10.1.10.2/24

Create a logical layer 3 VLAN interface on SWITCH-3 for management perpose.

set interfaces vlan unit 10 family inet address 10.1.10.3/24

Link the layer 2 VLAN to the layer 3 VLAN interface on SWITCH-1:

set vlans MANAGEMENT l3-interface irb.10
set vlans ADMIN l3-interface irb.20
set vlans IT l3-interface irb.30
set vlans ACCOUNTS l3-interface irb.40

Link the layer 2 VLAN to the layer 3 VLAN interface on SWITCH-2 and SWITCH-3:

set vlans MANAGEMENT l3-interface irb.10

Create a default route on SWITCH-2 and SWITCH-3 point to SWITCH-1.

This static route important for SWITCH-2 and SWITCH-3 for inter-vlan communication and traffic for internet. 

set routing-options static route 0.0.0.0/0 next-hop 10.1.10.1

Verify L3 ports and their status:

show interface terse

Output on SWITCH-1 in interface list.

irb.10                 up    up   inet     10.1.10.1/24
irb.20                 up    up   inet     10.1.20.1/24
irb.30                 up    up   inet     10.1.30.1/24
irb.40                 up    up   inet     10.1.40.1/24

Output on SWITCH-2 in interface list.

irb.10                 up    up   inet     10.1.10.2/24

Output on SWITCH-3 in interface list.

irb.10                 up    up   inet     10.1.10.3/24