[QFX] QFabric: Applying storm control on "all interfaces" including Aggregate Interfaces

Summary:

This article explains the behavior of storm control seen on Aggregate Ethernet interfaces (AE) with the below configuration.

 storm-control {
        action-shutdown;
        interface all {
            level 30;
            no-multicast;
        }
    }

It will also explain the behavior when Storm-control config is explicitly applied to AE interfaces.

storm-control {
action-shutdown;
interface all {
level 30;
no-multicast;
}

interface qf1-rsng1:ae10.0 {
level 50;
no-multicast;
}

Symptoms:

AE10 interface becomes disabled on RSNG1 (QFX5100) due to storm-control even if the threshold, i.e. 30% of AE10 = 6Gig is not crossed.

Storm-control config is applied on "interface all":


 storm-control {
        action-shutdown;
        interface all {
            level 30;
            no-multicast;
        }
    }

user@device> show lacp interfaces ae10          
Aggregated interface: ae10
    LACP state:       Role   Exp   Def  Dist  Col  Syn  Aggr  Timeout  Activity
      xe-0/0/15      Actor    No   Yes    No   No   No   Yes     Slow    Active
      xe-0/0/15    Partner    No   Yes    No   No   No   Yes     Fast   Passive
      xe-1/0/0       Actor    No   Yes    No   No   No   Yes     Slow    Active
      xe-1/0/0     Partner    No   Yes    No   No   No   Yes     Fast   Passive
    LACP protocol:        Receive State  Transmit State          Mux State 
      xe-0/0/15           Port disabled     No periodic           Detached
      xe-1/0/0            Port disabled     No periodic           Detached

Log messages:

2020-03-18T11:37:48.694Z qf1-rsng1 eswd 26768 ESWD_ST_CTL_ERROR_IN_EFFECT - ae10.0: storm control in effect on the port
2020-03-18T11:37:48.694Z qf1-rsng1 eswd 26768 ESWD_ST_CTL_ERROR_DISABLED - ae10.0: storm control disabled port
{MASTER}

user@device>

Solution:

storm-control {
        action-shutdown;
        interface all {
            level 30;
            no-multicast;
        }
}

As per the above config, whenever the broadcast and/or unknown unicast traffic exceeds the threshold of 30% BW on any child member interface of AE10 (xe-0/0/15 or xe-1/0/0) i.e. = 3Gig, the AE interface gets disabled along with all child members. In other words, when we apply storm control on "interface all" it gets applied to physical interfaces only. For AE interfaces we have to apply it explicitly.

user@device> show configuration ethernet-switching-options storm-control    
action-shutdown;
interface ae10.0 {
    level 30;
    no-multicast;
}
interface all {
    level 30;
    no-multicast;
}

So with the above config, whenever the broadcast or/and unknown unicast traffic exceeds 6 Gig i.e. 30% of AE10 BW storm-control will be in effect and disable the AE port along with child member interfaces.

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