Tuesday, November 22, 2016

Brocade ICX Switch: Up,Down (LACP-BLOCKED) Message On Interface

Ever see this message on an interface before?
GigabitEthernet1/2/2 is up, line protocol is down (LACP-BLOCKED)

I saw this last night when trying to connect a Cisco switch configured for a port-channel to a Brocade ICX7450 LAG.  Keep in mind, a LAG and Port-channel are the same thing, which is bonded ports for more throughput and redundancy.  In this case, we were using LACP.
Config for a Brocade LACP LAG in version 8.X:
lag LAG01 dynamic id 1
 ports ethernet 1/2/2 ethernet 1/2/4 
 primary-port 1/2/2
 port-name ***ToCisco*** ethernet 1/2/2

Because I was getting the error message above, I asked the other engineer if they had their side configured for LACP.  She said yes, but then she double checked and verified that she actually didn't have either "mode active" or "mode passive" with the "channel-group 1" command.  She actually had "mode auto", which uses port aggregation protocol (PagP) instead.  Simple mistake that we all make at some point.  She corrected and then the LAG came up and we started passing traffic.
Below is what I saw when I did a "show lag" on the Brocade side"
DIR_Irondale_(config)#sh lag
Total number of LAGs:          1
Total number of deployed LAGs: 1
Total number of trunks created:1 (255 available)
LACP System Priority / ID:     1 / 609c.9f3a.a488
LACP Long timeout:             120, default: 120
LACP Short timeout:            3, default: 3

=== LAG "LAG01" ID 1 (dynamic Deployed) ===
LAG Configuration:
   Ports:         e 1/2/2 e 1/2/4
   Port Count:    2
   Primary Port:  1/2/2
   Trunk Type:    hash-based
   LACP Key:      20001
Deployment: HW Trunk ID 1
Port       Link    State   Dupl Speed Trunk Tag Pvid Pri MAC             Name
1/2/2      Up      Blocked Full 1G    1     Yes 18   0   609c.9f3a.a488  ***ToCisco***
1/2/4      Up      Blocked  Full 1G   1     Yes 18   0   609c.9f3a.a488

Port       [Sys P] [Port P] [ Key ] [Act][Tio][Agg][Syn][Col][Dis][Def][Exp][Ope]
1/2/2           1        1   20001   Yes   S   Agg  Syn  Col  Dis  Def  No   Ina
1/2/4           1        1   20001   Yes   S   Agg  Syn  No   No   Def  No   Ina
Just know that if you get the above message (GigabitEthernet x/x/x is up, line protocol is down (LACP-BLOCKED), you have a LAG protocol mismatch.


  1. Beautiful, had this head scratcher today and had totally missed the fact 'laggproto lacp' wasn't set on the client-side BSD lagg0 port, meaning I had a mis-match. Many thanks for this post!

  2. Hi , Just want share below command , which i used to create LAG/LACP on brocade and cisco

    For Cisco

    Cisco IOS Port Channel/LAG Configuration
    Cisco(config)# interface port-channel 1
    Cisco(config-if)# switchport trunk encapsulation dot1q
    Cisco(config-if)# switchport trunk allowed vlan All
    Cisco(config-if)# switchport mode trunk
    Cisco(config-if)# switchport nonegotiate
    Cisco(config)# interface range g1/0/1 - 2
    Cisco(config-if-range)# switchport trunk encapsulation dot1q
    Cisco(config-if-range)# switchport trunk allowed vlan All
    Cisco(config-if-range)# switchport mode trunk
    Cisco(config-if-range)# switchport nonegotiate
    Cisco(config-if-range)# channel-group 1 mode active
    Cisco# show lacp 1 internal
    Cisco# show interfaces etherchannel


    For Brocade

    Brocade ICX LAG Configuration
    Brocade(config)# lag brocade dynamic id 11
    Brocade(config-lag-brocade)# ports ethernet 1/2/1 ethernet 1/2/2


    Hope is this informative for you.


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