Related Documentation
Example: Setting Up Basic Bridging and a VLAN on the QFX Series
The QFX Series products use bridging and virtual LANs (VLANs) to connect network devices—storage devices, file servers, and other LAN components—in a LAN and to segment the LAN into smaller bridging domains.
To segment traffic on a LAN into separate broadcast domains, you create separate virtual LANs (VLANs) on a switch. Each VLAN is a collection of network nodes. When you use VLANs, frames whose origin and destination are in the same VLAN are forwarded only within the local VLAN, and only frames not destined for the local VLAN are forwarded to other broadcast domains. VLANs thus limit the amount of traffic flowing across the entire LAN, reducing the possible number of collisions and packet retransmissions within the LAN.
This example describes how to configure basic bridging and VLANs for the QFX Series:
Requirements
This example uses the following software and hardware components:
- Junos OS Release 11.1 or later for the QFX Series
- A configured and provisioned QFX Series product
Overview and Topology
To use a switch to connect network devices on a LAN, you must at a minimum configure bridging and VLANs. By default, bridging is enabled on all switch interfaces, all interfaces are in access mode, and all interfaces belong to a VLAN called blue, which is automatically configured. When you plug in access devices—such as desktop computers, file servers, printers, and wireless access points—they are joined immediately into the blue VLAN, and the LAN is up and running.
The topology used in this example consists of a single QFX3500 switch, with a total of 48 10-Gbps Ethernet ports. (For the purposes of this example, the QSFP+ ports Q0-Q3, which are ports xe-0/1/0 through xe-0/1/15, are excluded.) You use the ports to connect devices that have their own power sources. Table 1 details the topology used in this configuration example.
Table 1: Components of the Basic Bridging Configuration Topology
Property | Settings |
|---|---|
Switch hardware | QFX 3500 switch, with 48 10-Gbps Ethernet ports |
VLAN name | blue |
Connections to file servers | xe-0/0/17 and xe-0/0/18 |
Unused ports | xe-0/0/0 through xe-0/0/16, and xe-0/0/19 through xe-0/0/47 |
Configuration
CLI Quick Configuration
By default, after you perform the initial configuration on the switch:
- Switching is enabled on all interfaces.
- A VLAN named blue is created.
- All interfaces are placed into this VLAN.
You do not need to perform any other configuration on the switch to set up bridging and VLANs. To use the switch, simply connect the servers to the ports xe-0/0/17 and xe-0/0/18.
Step-by-Step Procedure
To configure bridging and VLANs:
- Make sure the switch is powered on.
- Connect the two file servers to ports xe-0/0/17 and xe-0/0/18.
Results
Check the results of the configuration:
Verification
To verify that switching is operational and that a VLAN has been created, perform these tasks:
- Verifying That the VLAN Has Been Created
- Verifying That Interfaces Are Associated with the Proper VLANs
Verifying That the VLAN Has Been Created
Purpose
Verify that the VLAN named blue has been created on the switch.
Action
List all VLANs configured on the switch:
user@switch> show vlans
Name Tag Interfaces
blue
xe-0/0/0.0*, xe-0/0/1.0, xe-0/0/2.0, xe-0/0/3.0,
xe-0/0/4.0, xe-0/0/5.0, xe-0/0/6.0, xe-0/0/7.0,
xe-0/0/8.0*, xe-0/0/9.0, xe-0/0/10.0, xe-0/0/11.0*,
xe-0/0/12.0, xe-0/0/13.0, xe-0/0/14.0, xe-0/0/15.0,
xe-0/0/16.0, xe-0/0/17.0, xe-0/0/18.0, xe-0/0/19.0*,
xe-0/0/20.0, xe-0/0/21.0, xe-0/0/22.0, xe-0/0/23.0,
xe-0/0/24.0, xe-0/0/25.0, xe-0/0/26.0, xe-0/0/27.0,
xe-0/0/28.0, xe-0/0/29.0, xe-0/0/30.0, xe-0/0/31.0,
xe-0/0/32.0, xe-0/0/33.0, xe-0/0/34.0, xe-0/0/35.0,
xe-0/0/36.0, xe-0/0/37.0, xe-0/0/38.0, xe-0/0/39.0,
xe-0/0/40.0, xe-0/0/41.0, xe-0/0/42.0, xe-0/0/43.0,
xe-0/0/44.0, xe-0/0/45.0, xe-0/0/46.0, xe-0/0/47.0,
xe-0/1/0.0*, xe-0/1/1.0*, xe-0/1/2.0*, xe-0/1/3.0*
mgmt
me0.0*
Meaning
The show vlans command lists the VLANs configured on the switch. This output shows that the VLAN blue has been created.
Verifying That Interfaces Are Associated with the Proper VLANs
Purpose
Verify that Ethernet switching is enabled on switch interfaces and that all interfaces are included in the VLAN.
Action
List all interfaces on which switching is enabled:
user@switch> show ethernet-switching interfacesInterface State VLAN members Blocking xe-0/0/0.0 up blue unblocked xe-0/0/1.0 down blue blocked - blocked by STP/RTG xe-0/0/2.0 down blue blocked - blocked by STP/RTG xe-0/0/3.0 down blue blocked - blocked by STP/RTG xe-0/0/4.0 down blue blocked - blocked by STP/RTG xe-0/0/5.0 down blue blocked - blocked by STP/RTG xe-0/0/6.0 down blue blocked - blocked by STP/RTG xe-0/0/7.0 down blue blocked - blocked by STP/RTG xe-0/0/8.0 up blue unblocked xe-0/0/9.0 down blue blocked - blocked by STP/RTG xe-0/0/10.0 down blue blocked - blocked by STP/RTG xe-0/0/11.0 up blue unblocked xe-0/0/12.0 down blue blocked - blocked by STP/RTG xe-0/0/13.0 down blue blocked - blocked by STP/RTG xe-0/0/14.0 down blue blocked - blocked by STP/RTG xe-0/0/15.0 down blue blocked - blocked by STP/RTG xe-0/0/16.0 down blue blocked - blocked by STP/RTG xe-0/0/17.0 down blue blocked - blocked by STP/RTG xe-0/0/18.0 down blue blocked - blocked by STP/RTG xe-0/0/19.0 up blue unblocked xe-0/0/20.0 down blue blocked - blocked by STP/RTG xe-0/0/21.0 down blue blocked - blocked by STP/RTG xe-0/0/22.0 down blue blocked - blocked by STP/RTG xe-0/0/23.0 down blue blocked - blocked by STP/RTG xe-0/0/24.0 down blue blocked - blocked by STP/RTG xe-0/0/25.0 down blue blocked - blocked by STP/RTG xe-0/0/26.0 down blue blocked - blocked by STP/RTG xe-0/0/27.0 down blue blocked - blocked by STP/RTG xe-0/0/28.0 down blue blocked - blocked by STP/RTG xe-0/0/29.0 down blue blocked - blocked by STP/RTG xe-0/0/30.0 down blue blocked - blocked by STP/RTG xe-0/0/31.0 down blue blocked - blocked by STP/RTG xe-0/0/32.0 down blue blocked - blocked by STP/RTG xe-0/0/33.0 down blue blocked - blocked by STP/RTG xe-0/0/34.0 down blue blocked - blocked by STP/RTG xe-0/0/35.0 down blue blocked - blocked by STP/RTG xe-0/0/36.0 down blue blocked - blocked by STP/RTG xe-0/0/37.0 down blue blocked - blocked by STP/RTG xe-0/0/38.0 down blue blocked - blocked by STP/RTG xe-0/0/39.0 down blue blocked - blocked by STP/RTG xe-0/0/40.0 down blue blocked - blocked by STP/RTG xe-0/0/41.0 down blue blocked - blocked by STP/RTG xe-0/0/42.0 down blue blocked - blocked by STP/RTG xe-0/0/43.0 down blue blocked - blocked by STP/RTG xe-0/0/44.0 down blue blocked - blocked by STP/RTG xe-0/0/45.0 down blue blocked - blocked by STP/RTG xe-0/0/46.0 down blue blocked - blocked by STP/RTG xe-0/0/47.0 down blue blocked - blocked by STP/RTG xe-0/1/0.0 up blue unblocked xe-0/1/1.0 up blue unblocked xe-0/1/2.0 up blue unblocked xe-0/1/3.0 up blue unblocked me0.0 up mgmt unblocked
Meaning
The show ethernet-switching interfaces command lists all interfaces on which switching is enabled (in the Interfaces column), along with the VLANs that are active on the interfaces (in the VLAN members column). Notice that the interfaces listed are the logical interfaces, not the physical interfaces. For example, the output shows xe-0/0/0.0 instead of xe-0/0/0. This is because Junos OS creates VLANs on logical interfaces, not directly on physical interfaces.
