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How to display the local FDB tables

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TitleHow to display the local FDB tables
Objective
How to display the local FDB tables
 
Environment
EXOS
Procedure
  • MAC addresses are added to the Forwarding Database (FDB) based on the source MAC address field in a frame received on a port. This frame could be an ARP packet or an IP packet. This type of learning is called dynamic learning
  • Static entries can also be manually added to the FDB where dynamic learning of addresses is meant to be disabled for security reasons
The FDB table can be viewed from a number of perspectives as outlined below:
  • Viewing the entire FDB table:
# show fdb
Mac                     Vlan       Age  Flags           Port / Virtual Port List
--------------------------------------------------------------------------------
00:00:25:09:c6:4d        Q01(0100) 0008  d m            1 
00:04:96:20:aa:00        Q02(0200) 0008  d m            11 
00:04:96:27:7c:5a        Q01(0100) 0008  d m            2 
00:04:96:51:6b:ce        Q02(0100) 0008  d m            12 
00:04:96:51:7c:46        Q03(0100) 0008  d m            21
00:00:25:09:c6:5e        Q01(0100) 0008  d m            1
  • Viewing the FDB table from the perspective of a VLAN:
# show fdb vlan "Q01"
Mac                     Vlan       Age  Flags           Port / Virtual Port List
--------------------------------------------------------------------------------
00:00:25:09:c6:4d        Q01(0100) 0036  d m            1
00:00:25:09:c6:5e        Q01(0100) 0008  d m            1
00:04:96:27:7c:5a        Q01(0100) 0008  d m            2
  • Viewing the FDB table from the perspective of a Port:
# show fdb ports 1
Mac                     Vlan       Age  Flags           Port / Virtual Port List
--------------------------------------------------------------------------------
00:00:25:09:c6:4d        Q01(0100) 0042  d m            7
  • Flags relevant to each output above:
Flags : d - Dynamic, s - Static, p - Permanent, n - NetLogin, m - MAC, i - IP,
        x - IPX, l - lockdown MAC, L - lockdown-timeout MAC, M- Mirror, B - Egress Blackhole,
        b - Ingress Blackhole, v - MAC-Based VLAN, P - Private VLAN, T - VLAN translation,
        D - drop packet, h - Hardware Aging, o - IEEE 802.1ah Backbone MAC,
        S - Software Controlled Deletion, r - MSRP,
        R - TRILL Rbridge, Z - OpenFlow

Total: 6 Static: 0  Perm: 0  Dyn: 6  Dropped: 0  Locked: 0  Locked with Timeout: 0
FDB Aging time: 300
Additional notes
Note:
  • FDB entries are learnt on Ingress and NOT on Egress, therefore, running the show fdb ports <port-number>  command on a port that is only transmitting (TX) traffic won't show any entries
  • Virtual MAC addresses embedded in the payload of IP ARP packets can be learned when this feature is enabled.

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