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Age column of the MAC forwarding table.

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  • 1.  Age column of the MAC forwarding table.

     
    Posted 02-07-2021 06:26
    Hi.

    I never see the 'Age' column of the MAC table populated.

    {master:0}

    lab@ex1> show ethernet-switching table

     

    MAC flags (S - static MAC, D - dynamic MAC, L - locally learned, P - Persistent static, C - Control MAC

               SE - statistics enabled, NM - non configured MAC, R - remote PE MAC, O - ovsdb MAC)

     

     

    Ethernet switching table : 4 entries, 4 learned

    Routing instance : default-switch

        Vlan                MAC                 MAC         Age    Logical                NH        RTR

        name                address             flags              interface              Index     ID

        v11                 c0:bf:a7:ee:b6:a5   D             -   ge-0/0/4.0             0         0      

        v11                 c0:bf:a7:ee:d1:41   D             -   ge-0/0/4.0             0         0      

        v12                 c0:bf:a7:ee:b6:a6   D             -   ge-0/0/4.0             0         0      

        v12                 c0:bf:a7:ee:d1:41   D             -   ge-0/0/4.0             0         0  


    Does the above CLI command every display a MAC's age?
    Is there any other command that can give me a MAC entry's age?

    Thanks,
    Deepak


  • 2.  RE: Age column of the MAC forwarding table.

     
    Posted 02-07-2021 19:38
    Just add detail or extensive to the command to get more information including the age of the entry.

    ------------------------------
    Steve Puluka BSEET - Juniper Ambassador
    IP Architect - DQE Communications Pittsburgh, PA (Metro Ethernet & ISP)
    http://puluka.com/home
    ------------------------------



  • 3.  RE: Age column of the MAC forwarding table.
    Best Answer

     
    Posted 02-08-2021 02:48
    Hi Deepak,

    As per the below documentation it is not supported.

    https://www.juniper.net/documentation/en_US/junos13.2/topics/reference/command-summary/show-ethernet-switching-table-l2.html

    Thanks


  • 4.  RE: Age column of the MAC forwarding table.

     
    Posted 02-08-2021 02:53
    Thanks raviky.


  • 5.  RE: Age column of the MAC forwarding table.

     
    Posted 02-08-2021 06:03

    root> show ethernet-switching table extensive

    Ethernet-switching table: 15 entries, 12 learned, 0 persistent entries

        

        VLAN: Guest, Tag: 5, MAC: *, Interface: All-members

        Interfaces:

                     ge-0/0/46.0

        Type: Flood

        Action: Forward

        Nexthop index: 1315

        

        VLAN: Guest, Tag: 5, MAC: 00:12:01:1e:eb:4c, Interface: ge-0/0/46.0

        Type: Learn, Age: 0, Learned: 5w0d 19:18:08

        Action: Forward

        Nexthop index: 1314

    root> show ethernet-switching table detail       

    Ethernet-switching table: 15 entries, 12 learned, 0 persistent entries

        

        VLAN: Guest, Tag: 5, MAC: *, Interface: All-members

        Interfaces:

                     ge-0/0/46.0

        Type: Flood

        Action: Forward

        Nexthop index: 1315

        

        VLAN: Guest, Tag: 5, MAC: 00:12:01:1e:eb:4c, Interface: ge-0/0/46.0

        Type: Learn, Age: 0, Learned: 5w0d 19:18:37

        Action: Forward

        Nexthop index: 1314



    ------------------------------
    Steve Puluka BSEET - Juniper Ambassador
    IP Architect - DQE Communications Pittsburgh, PA (Metro Ethernet & ISP)
    http://puluka.com/home
    ------------------------------



  • 6.  RE: Age column of the MAC forwarding table.

    Posted 02-08-2021 10:02
    @spuluka

    I think it's platform dependent... on the old ones (EX3200/EX4200) it was shown/supported but the following entry is from an EX2300 running 18.2R3-S2 does not show this information anymore. You have to dig into the mac-learning-log to try matching age of the entry.


    ​user@ex2300> show ethernet-switching table extensive 00:50:56:a1:ea:84

    MAC address: 00:50:56:a1:ea:84
    Routing instance: default-switch
    VLAN name: V16, VLAN ID: 16
    Learning interface: ge-0/0/32.0
    Layer 2 flags: in_hash,in_ifd,in_ifl,in_vlan,in_rtt,kernel,in_ifbd
    Epoch: 34 Sequence number: 2
    Learning mask: 0x00000001

    ------------------------------
    --
    Jonas Hauge Klingenberg - Juniper Ambassador
    ------------------------------



  • 7.  RE: Age column of the MAC forwarding table.

    Posted 02-08-2021 10:15
    Being redundant , confirming there is no age timer on 23/3400 running Junos 19.4R1.10  20.3R1-S1.2,  20.2R2.11