某局点S7606X堆叠口流量不均衡问题

两台S7606-X设备做堆叠，堆叠口为37到48口。

两台S7606-X做堆叠，堆叠口包括37到48口，现场发现37口的流量偏大，大约占用带宽20%，其他堆叠口只有2%-4%。看收发包计数，发现只有37口有广播流量，虽然广播流量都走主堆叠口， 但从数据看，广播流量和单播、组播流量也不是一个量级的，大部分都是单播流量，单播流量应该是可以在堆叠口哈希的

堆叠跨板hash，组播/广播/未知单播都走主堆叠口，单播会进行hash，但是这里客户配置了mac不老化，导致mac超规格，单播变成未知单播，都走了主堆叠口。

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mac-address timer no-aging

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  ===============display mac-address=============== 

MAC Address      VLAN ID    State            Port/Nickname            Aging

10e8-78ce-6a92   10         Learned          BAGG3                    N

10e8-78cd-5692   11         Learned          BAGG4                    N

10e8-78ce-6a92   50         Learned          BAGG3                    N

%Dec 24 00:34:31:729 2020 SHNQ-PA-CMNET-SW03-lyljf7606X RESMON/3/RESMON_SEVERE: -Chassis=1-Slot=4; -Resource=mac-Total=163840-Used=163570-Free=270; Free resource decreased to or below severe threshold 10%.

%Dec 24 00:34:32:154 2020 SHNQ-PA-CMNET-SW03-lyljf7606X RESMON/3/RESMON_SEVERE: -Chassis=2-Slot=0; -Resource=mac-Total=163840-Used=163572-Free=268; Free resource decreased to or below severe threshold 10%.

%Dec 24 00:58:11:770 2020 SHNQ-PA-CMNET-SW03-lyljf7606X RESMON/3/RESMON_SEVERE: -Chassis=2-Slot=4; -Resource=mac-Total=163840-Used=163559-Free=281; Free resource decreased to or below severe threshold 10%.

%Dec 24 01:40:59:546 2020 SHNQ-PA-CMNET-SW03-lyljf7606X RESMON/3/RESMON_SEVERE: -Chassis=1-Slot=0; -Resource=mac-Total=163840-Used=163578-Free=262; Free resource decreased to or below severe threshold 10%.

可以通过如下命令查看哪个接口是主堆叠口

 ====debug stack show portinfo chassis 1 slot 1==== 

=============================================================

           Port Information of STACK Module

=============================================================

Stack 1

    Portnum: 0,  ActiveNum:0,  IsShutDown:0, Mtu:0,  FwdStat:???

    PortOnBoard:

    Stack Ports:       Master~255/255/255:255   IsChecked:1

Stack 2

    Portnum: 12,  ActiveNum:12,  IsShutDown:0, Mtu:0,  FwdStat:FOWARD

    PortOnBoard:  Slot 1:(12,12)

    Stack Ports:       Master~1/0/37:0   IsChecked:1

      1: 1/0/37:0, PortType:2, IsActive:1, HgMode:1 (1), IsShutDown:0, LogSlot: 1

      2: 1/0/38:0, PortType:2, IsActive:1, HgMode:1 (1), IsShutDown:0, LogSlot: 1

      3: 1/0/39:0, PortType:2, IsActive:1, HgMode:1 (1), IsShutDown:0, LogSlot: 1

      4: 1/0/40:0, PortType:2, IsActive:1, HgMode:1 (1), IsShutDown:0, LogSlot: 1

      5: 1/0/41:0, PortType:2, IsActive:1, HgMode:1 (1), IsShutDown:0, LogSlot: 1

      6: 1/0/42:0, PortType:2, IsActive:1, HgMode:1 (1), IsShutDown:0, LogSlot: 1

      7: 1/0/43:0, PortType:2, IsActive:1, HgMode:1 (1), IsShutDown:0, LogSlot: 1

      8: 1/0/44:0, PortType:2, IsActive:1, HgMode:1 (1), IsShutDown:0, LogSlot: 1

      9: 1/0/45:0, PortType:2, IsActive:1, HgMode:1 (1), IsShutDown:0, LogSlot: 1

      10: 1/0/46:0, PortType:2, IsActive:1, HgMode:1 (1), IsShutDown:0, LogSlot: 1

      11: 1/0/47:0, PortType:2, IsActive:1, HgMode:1 (1), IsShutDown:0, LogSlot: 1

      12: 1/0/48:0, PortType:2, IsActive:1, HgMode:1 (1), IsShutDown:0, LogSlot: 1

建议现场将mac地址配置成可老化，防止mac超规格产生大量未知单播流量。 补充：同一堆叠单板，同一芯片的堆叠口可以进行聚合hash；但对于跨单板聚合的情况，如果当本堆叠单板的堆叠口流量打满后，不会hash再到其它单板的堆叠口，应该避免有过大的跨框流量，尽量本框优先转发。