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SG300-10 VLANs Suddenly keep dropping

I have a Cisco SG300-10 which is configured to be in layer 3 mode.

I have configured GE7 into trunk mode and I have tagged the VLANS 10 and 11 to this VLAN.

VLANS 10 and 11 respectively are set-up with correct IP configuration

VLAN 10 is

VLAN 11 is

On the other side of GE7 is my ESXi host and the management port is tagged to VLAN 10 with an IP address of

I also have a VMnetwork port group attached to GE7 and this is tagged to VLAN11.

I also have local machine just used for testing connectivity and stuff attached to GE2 which has the default settings of being on the native VLAN.

Doing a "show ip route" will show all the direct connected VLANS as connected.

Now my issue.

From my local machine I can ping the gateway address of VLAN10 ( and also the ESXi host management IP of ( However, after a period of say 5 minutes I will loose connectivity to VLAN10, both the gateway IP address and the ESXi management IP address. To resolve this and get the VLAN activated again i hope onto the console of the ESXi host and ping its gateway address on VLAN10 ( and this brings the VLAN back online, and my local machine can once again ping and manage the ESXi host (for another 5 mins or so before it goes offline again)

Secondary to this issue.

On the ESXi host i have a virtual machine connected to the port group on VLAN11 and IP'd with an address of As soon as this virtual machine pings its VLAN11 gateway it will turn off VLAN10's connectivity again. The only way to re-mediate connectivity to VLAN10 is to hop onto the ESXi host and ping its VLAN10 gateway again (thus in turn this stops connectivity virtual machine again on VLAN11)

This is totally consistent behaviour, when both VLANs are tagged to the port (i have tried other ports too) then they will only stay active for approx 5 minutes, and if you communicate with the other VLAN which is tagged to the port then it will turn off the other VLAN which is connected to the same port.

I have the latest firmware and bootcode for this device.

Has anyone else experienced issues like this where VLANs seem to randomly deactivate and when working you can only have connectivity to a single VLAN on the trunked port ?

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