04-13-2021 07:08 AM
Hi,
I have a cisco sg350x 24 port with 10gig uplinks running as as small scale isp distribution switch
my network scenario is i have 3 different isp routers connected to 1 gig ports
remaining were used as downlinks. I am getting this error "%2SWMACTBL-N-PORTMACHASHFAILED: Port gi1/0/24 ,MAC 7c:a9:6b:73:e3:c2 : Cannot be added to the FDB (Hash Table Collision)" frequently. every now and then with different mac address. switch has approx 330 active vlans. i couln't find any hardware loop or soft loop in my network.
any help would be much appreciated.
Solved! Go to Solution.
04-13-2021 11:43 PM
Hello,
the number of drop events when compared to total packets received leads to a low drop probability that should not be an issue
Hope to help
Giuseppe
04-13-2021 08:57 AM
Hello @jakirbasasha69,
verify if the same MAC address is learned on another VLAN on another port at the same time.
We have seen a similar issue on recent IOS switch C3560 with IOS XE 16.9.5 in a customer network.
We have found that this case same MAC address learned on different VLANs on different ports caused log messages similar to yours.
However,
>> switch has approx 330 active vlans
This looks like to be an high number for a device like yours that is intended for small business not ISP level.
How many MAC addresses are learned ?
Hope to help
Giuseppe
04-13-2021 10:08 AM - edited 04-13-2021 10:11 AM
04-13-2021 11:43 PM
Hello,
the number of drop events when compared to total packets received leads to a low drop probability that should not be an issue
Hope to help
Giuseppe
11-14-2022 11:35 PM
same mac learned on two different port
12-28-2022 11:18 AM
A que te réferis que se aprende?
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