I’ve already written a post on how to create a Virtual Chassis by using the 1/10GB uplink modules. If you have a switch in production and want to add another switch for additional ports or redundancy, you can easily create a virtual chassis. This time I’ll be using the dedicated VC ports and cables and adding a new switch to a production switch. I’ll be using the preprovisioned method, and before I do any virtual chassis configuration I’ll need to add some features to the master member to minimize failover times:

set system commit synchronize
set chassis redundancy graceful-switchover
set routing-options nonstop-routing
set ethernet-switching-options nonstop-bridging

Having added these features, we can now configure preprovisioned virtual chassis onto the master switch, which will become member 0. Because this is only a 2 member VC, I’ve added the no-split-detection command as recommended by Juniper, and to help with the failover times fast-failover on all ports ge/xe that have been enabled.

set virtual-chassis preprovisioned
set virtual-chassis no-split-detection
set virtual-chassis member 0 role routing-engine
set virtual-chassis member 0 serial-number BP0214340104
set virtual-chassis member 1 role routing-engine
set virtual-chassis member 1 serial-number BP0215090120
set virtual-chassis fast-failover ge
set virtual-chassis fast-failover xe

For now, that’s everything on the master member. On the new switch (member 1), you need to clear all config from the switch and set the root password to allow you to commit your changes:

root> edit 
Entering configuration mode
root# delete 
This will delete the entire configuration
Delete everything under this level? \[yes,no\] (no) yes 
root# set system root-authentication plain-text-password    
New password:
Retype new password:
root# commit 
configuration check succeeds
commit complete

You need to ensure there are no past virtual chassis configurations, and you can do this by entering the shell cli of the switch and removing anything in the vchassis folder:

root> start shell 
root@:RE:0% rm -rf /config/vchassis/\*
root@:RE:0% cd /config/vchassis/
root@:RE:0% ls -la
total 8
drwxr-xr-x  2 root  wheel  512 Sep 13 07:26 .
drwxr-xr-x  5 root  wheel  512 Sep 13 06:57 ..
root@:RE:0% exit

Now you will need to power off the backup member for at least a minute, to ensure that the other switch is elected as master. After the minute, patch the VC-cable into the dedicated VCP-Ports at the back of the chassis and power on the backup switch. Once member 1 has booted you will be able to verify the new member by running: show virtual-chassis status

root@EX4200-A> show virtual-chassis status     
Preprovisioned Virtual Chassis
Virtual Chassis ID: f1a1.ca8e.bbba
Virtual Chassis Mode: Enabled
                                           Mstr           Mixed Neighbor List
Member ID  Status   Serial No    Model     prio  Role      Mode ID  Interface
0 (FPC 0)  Prsnt    BP0214340104 ex4200-48t 129  Master\*      N  1  vcp-0      
                                                                 1  vcp-1      
1 (FPC 1)  Prsnt    BP0215090120 ex4200-48t 129  Backup       N  0  vcp-0      
                                                                 0  vcp-1  

And you can verify the health of the VCP ports by running: show virtual-chassis vc-port

root@EX4200-A> show virtual-chassis vc-port    
Interface   Type              Trunk  Status       Speed        Neighbor
or                             ID                 (mbps)       ID  Interface
PIC / Port
vcp-0       Dedicated           1    Up           32000        1   vcp-0  
vcp-1       Dedicated           2    Up           32000        1   vcp-1  
Interface   Type              Trunk  Status       Speed        Neighbor
or                             ID                 (mbps)       ID  Interface
PIC / Port
vcp-0       Dedicated           1    Up           32000        0   vcp-0  
vcp-1       Dedicated           2    Up           32000        0   vcp-1
Share on LinkedIn
Share on Reddit