SG500 mac address learning is wrong

[LACOUSTICS92]

Hello

I'm facing to a very strange behavior in the small business switches.

For a reason that I ignore the small business learn mac address in a wrong way.

I have 2 Pc that are connected to 2 differents switches 

1 PC is connected to a small business SG500

1 PC is connected to a catalyst C3850

the small business and the catalyst are connected to each other via 1 uplink (in trunk)

When I disconnect the PC from the Catalyst, for a reason that I ignore the mac address of this PC is learned by the small business in an interface that is UP.

In the SG500 when I'm typing "show mac address--table interface giX/X/X, it lists the 2 mac adresses.

here is the version of the small business

Unit SW version Boot version HW version
------------------- ------------------- ------------------- -------------------
1 1.4.11.4 1.4.0.02 V03

I don't know if it'a a known issue or not.

Can someone helps me to figure it out please? 

thank you very much for your help

best regards

John 

[balaji.bandi]

Can you provide show output, "show mac address--table interface giX/X/X, it lists the 2 mac adresses.

[LACOUSTICS92]

Thank you for your response Balaji,

yes of course, here is the output 

LAFR1-RDC02-SG500...#sh mac address-table interface gi3/1/12
Flags: I - Internal usage VLAN
Aging time is 300 sec

Vlan Mac Address Port Type
------------ --------------------- ---------- ----------
3 00:0a:f7:bb:7b:4b gi3/1/12 dynamic
3 34:e6:d7:85:02:3b gi3/1/12 dynamic

LAFR1-RDC02-SG500...#sh run int gi3/1/12
interface gigabitethernet3/1/12
switchport mode access
switchport access vlan 3

and there is only one machine that is connected to the switch.

last our the mac address was seen in the port gi2/1/44, since this port is down the mac address moves to the port gi3/1/12

and the machine is connected to a catalyst.

I don't understand what's going on with the SG switches. 

[balaji.bandi]

00:0a:f7:bb:7b:4b  - this broadcom vendor lookup

34:e6:d7:85:02:3b - this dell PC (may be)

show ip arp - what you see association with IP address ?

[LACOUSTICS92]

here it is 

the ip arp is in the Core network, the mac address is kept for 216 min

of course the PC doesn't respond to the ping (no firewall activated on the PC)

C9300-CR01#sh ip arp 34e6.d785.023b
Protocol Address Age (min) Hardware Addr Type Interface
Internet 172.16.3.88 216 34e6.d785.023b ARPA Vlan3

C9300-CR01#show mac address-table aging-time
Global Aging Time: 300
Vlan Aging Time
---- ----------

[balaji.bandi]

what is the output

show ip arp |  in 00:0a:f7:bb:7b:4b

[LACOUSTICS92]

Hello Balaji;

There is no binding with this mac address.