Building a Two-unit Linear-topology Trunk Manually

The following procedure uses an ICX 7250 stack as an example. A two-unit ICX 7250 stack has two potential linear-topology trunks, (x/2/1 to x/2/4) and (x/2/5 to x/2/8). The following figure shows the appropriate cabling for the four-port linear topology trunk (x/2/1 to x/2/4) on an ICX 7250 two-unit stack configured in the following procedure.

ICX 7250-24P Two-unit Stack with Linear-topology Trunk as Configured in Example

Note: If you configure an ICX 7750 two-unit stack, you have the choice of two linear-topology trunks. For example, you can configure stack-trunk 1/2/1 to 1/2/6 1/3/1 to 1/3/6 or stack-trunk 1/2/5 to 1/2/6 1/3/5 to 1/3/6. Both trunks contain ports in two slots.

Complete the following steps to configure a two-unit linear-topology trunk manually (in this case, on an ICX 7250 two-unit stack).

  1. On both units, create the desired trunk in stack unit configuration sub-mode. 
    ICX7250# configure terminal
ICX7250(config)# stack unit 1
ICX7250(config-unit-1)# stack-trunk 1/2/1 to 1/2/4
    The example configures ports 1/2/1 through 1/2/4 as a stacking trunk on one of the stack unit candidates. Enter the trunk configuration on the other unit, too.
  2. Enter the stack enable command on both units. 
    ICX7250(config-unit-1)# exit
ICX7250(config)# stack enable
  3. Connect cables between the two units. (For this example, connect four cables.)

    Once connected, both units perform elections to choose the active controller. The unit that loses the election is reloaded as a stack member and later is assigned the standby role.

    When the member boots up, it joins, and a two-unit stack forms.

  4. Enter the write memory command to save the learned configuration. 
    ICX7250(config)# write memory

The following example shows the manual formation of a two-unit ICX 7250 linear-topology stack. 

====================Unit 1 Log============================
ICX7250-48P Router# configure terminal
ICX7250-48P Router(config)# stack unit 1
ICX7250-48P Router(config-unit-1)# stack-trunk 1/2/1 to 1/2/4
stack-trunk 1/2/1 to 1/2/4 replaces stack-port 1/2/1 and stack-port 1/2/3
ICX7250-48P Router(config-unit-1)# stack enable
Enable stacking. This unit actively participates in stacking
ICX7250-48P Router(config-unit-1)# end

ICX7250-48P Router# show running-config 
Current configuration:
!
ver 08.0.90
!
stack unit 1
  module 1 icx7250-48p-poe-port-management-module
  module 2 icx7250-sfp-plus-8port-80g-module
  stack-trunk 1/2/1 to 1/2/4
  
stack enable
stack mac 609c.9f99.1988
!
!
hitless-failover enable
!
!
end

ICX7250-48P Router#
T=2m20.4: Election, was alone --> active, ID=1, pri=0, 2U(1-2), A=u1, nbr#=1 0, reason: u2: hitle-fail-en, , 
T=2m23.0: Election, was active, no change, ID=1, pri=0, 2U(1-2), A=u1, nbr#=1 0, reason: u1: stk-po-chg, , 
T=2m25.9: reset unit 2: u2 bootup-id=1

Config changed due to add/del units. Do write mem if you want to keep it
T=2m31.0: Unit 1 loses all neighbors.
T=2m31.0: Active U1 deletes U2 and its config because it is learned.


=====================unit 2 log==================================
ICX7250-48P Router# configure terminal
ICX7250-48P Router(config)# stack unit 1
ICX7250-48P Router(config-unit-1)# stack-trunk 1/2/1 to 1/2/4
stack-trunk 1/2/1 to 1/2/4 replaces stack-port 1/2/1
ICX7250-48P Router(config-unit-1)# stack enable
Enable stacking. This unit actively participates in stacking
ICX7250-48P Router(config-unit-1)# end

ICX7250-48P Router# show running-config
Current configuration:
!
ver 08.0.90
!
stack unit 1
  module 1 icx7250-48p-poe-port-management-module
  module 2 icx7250-sfp-plus-8port-80g-module
  stack-trunk 1/2/1 to 1/2/4
  
stack enable
stack mac 609c.9f99.3f80
!
!
hitless-failover enable
!
!
end

ICX7250-48P Router# 
T=2m23.4: Election, was alone --> member, ID=2, pri=0, 2U(1-2), A=u1, nbr#=1 0, reason: u1: hitle-fail-en, , 
My assigned ID is 2, but my bootup ID is 1, need reload
T=2m29.1: Boot request from u1 mac=609c.9f99.1988, reason: u2 bootup-id=1, flash: Primary, jumbo=0, 
Unmounting the External USB
We are in system reset

####  Bootup Printout is snipped

The system : started=warm start   reloaded=by "reload"
My stack unit ID = 2, bootup role = member


[MEMBER]local-2@ICX7250-48P Router>
Creating certificate, please wait...

SSL Client Certificate is successfully created

[MEMBER]local-2@ICX7250-48P Router>

T=45.5: Election, was member, no change, ID=2, pri=0, 2U(1-2), A=u1, nbr#=1 0, reason: u1: nbr-no-stk-p, , 
Unit 2 becomes ready
Connecting to active controller 1 console...(Press Ctrl Shift -  x to exit)
T=48.5: Election, was member, no change, ID=2, pri=0, 2U(1-2), A=u1, nbr#=1 0, reason: u1: stk-po-chg, , 
ICX7250-48P Router>UNIT2:T=1m49.8: Unit 2 is assigned standby by active u1. 
T=1m52.0: Standby u2 start parsing running config from active controller u1
T=1m52.3: Standby u2 finished parsing running config from active controller u1.
T:1m54.5: Done hot swap: standby controller u2 sets u1 to Ready.

ICX7250-48P Router# show running-config
Current configuration:
!
ver 08.0.90
!
stack unit 1
  module 1 icx7250-48p-poe-port-management-module
  module 2 icx7250-sfp-plus-8port-80g-module
  stack-trunk 1/2/1 to 1/2/4
  
stack unit 2
  module 1 icx7250-48p-poe-port-management-module
  module 2 icx7250-sfp-plus-8port-80g-module
  stack-trunk 2/2/1 to 2/2/4
  
stack enable
stack mac 609c.9f99.1988
!
!
ICX7250-48P Router# show stack
T=38m56.4: alone: standalone, D: dynamic cfg, S: static
ID   Type          Role    Mac Address    Pri State   Comment                   
1  S ICX7250-48P   active  609c.9f99.1988   0 local   Ready
2  D ICX7250-48P   standby 609c.9f99.3f80   0 remote  Ready

    standby      active                                                        
     +---+        +---+                                                        
     | 2 |2/1==2/1| 1 |                                                        
     +---+        +---+                                                        
Standby u2 - protocols ready, can failover or manually switch over
Role history: N: standalone, A: active, S: standby, M: member
U1: N->A

Current stack management MAC is 609c.9f99.1988
ICX7250-48P Router# write memory
Parent topic: Configuring Two-unit Stack Linear-topology Trunks