Port is UP. But Mac is unavailable.

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We have a remote Summit X450G2-24t-G4 switch running XOS
I can see a device (VOIP related device) is connected to a port  (port is admin up and oper up). 
But I cannot see the MAC when "show fdb" is given. What could be the reason ? Device is given a Static ip. (Not in ARP table too.)
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Posted 2 years ago

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Henrique, Employee

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Hi Weda, Is it possible to connect a PC to that port and check?
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Bastian Sprotte, Employee

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Hi Weda,
use the
show port 3 information detail
to verify that vlan is defined on the port as well as no STP blocking is happen.
these would 2 event that no FDB learing will happen.

also check if packets are send into the port via the statistics
show port 3 statistics no-refresh

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Jason Parker, Employee

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is the item on a different VLAN than assigned (tagged 22 when it should using 33?
Is one side tagged vs. untagged
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simon bingham

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I second this, Phone is in one VLAN, switch port does not have same vlan