Redundant Trunk Group (RTG) is a feature on the EX/QFX switches.  This feature eliminates the need to configure STP on the switch that has RTG configured.  RTG is similar to RSTP Root and Alternate port, but without the need of configuring RSTP.

 

Ideally implemented on switch with a dual home connection where device need a fast, deterministic failover mechanism.  - one link will be active and forwarding traffic and the other is blocking and backup to the active link. RTG will be implemented mainly between access and distribution layer of devices.

 

 

 

 

Configuration on Switch 1: user@switch# set protocols rstp disable

 

Configuration on Switch 2: user@switch# set protocols rstp disable

 

Configure redundant trunk group rtg0 on Switch 3:

 

user@switch#[edit]
 set protocols rstp disable
 set switch-options redundant-trunk-group group rtg0 interface ge-0/0/9.0 primary
 set switch-options redundant-trunk-group group rtg0 interface ge-0/0/10.0
 set switch-options redundant-trunk-group group rtg0 preempt-cutover-timer 60

 

Verification:

 

user@switch> show redundant-trunk-group 
Group      Interface   State       Time of last flap           Flap
name                                                           count

rtg0       ge-0/0/9.0  Up/Pri      Never                         0
           ge-0/0/10.0 Up          Never                         0

For Non-ELS:

Configuration on Switch 1: user@switch# set protocols rstp disable

Configuration on Switch 2: user@switch# set protocols rstp disable

Configure redundant trunk group rtg0 on Switch 3:

user@switch[edit]
 set protocols rstp disable
 set ethernet-switching-options redundant-trunk-group group rtg0 interface ge-0/0/9.0 primary
 set ethernet-switching-options redundant-trunk-group group rtg0 interface ge-0/0/10.0
 set ethernet-switching-options redundant-trunk-group group rtg0  preempt-cutover-timer 60

 

Verification:

 

user@switch> show redundant-trunk-group 
Group      Interface   State       Time of last flap           Flap
name                                                           count

rtg0       ge-0/0/9.0  Up/Pri      Never                         0
           ge-0/0/10.0 Up          Never                         0

preempt-cutover-time >> A primary link takes over whenever it is able. However, configuring preempt timer alter the number of seconds that the primary link waits before reestablishing its control.

 

Note: Rapid Spanning Tree Protocol (RSTP) is enabled by default on EX Series switches to create a loop-free topology, but an interface is not allowed to be in both a redundant trunk group and in a spanning-tree protocol topology at the same time. You will need to disable RSTP on the two distribution switches in the example, Switch 1 and Switch 2. Spanning-tree protocols can, however, continue operating in other parts of the network—for example, between the distribution switches and also in links between distribution switches and the enterprise core.