Switch making connection 192.168.1.100

Are you sure there is no other device competing for this IP-address?

there is no other device using this ip-address.

When I disconnect port the ip is unreachable

Did you follow that KB document exactly?

Then your switch should have 172.16.16.239 or a DHCP assigned one. Try to update firmware image without pushing a different config at first.

that is the problem.

The switch is not available in Central and I am unable to connect by web or SSH

then there is the problem that I can not find firmware on website from Sophos, that is my other question  

 Sophos Cloud Switch CS101-8FP Download recovery image 

Likely the switch is broken. The DHCP packets, you localize, are not DHCP. They are TFTP Packets, which are also using Port 69. The Switch is looking for a TFTP Server to fetch the bootfile. 

So the easiest way would be to get the Switch replaced by an RMA. 

Otherwise, you can follow up on that one: https://support.sophos.com/support/s/article/KB-000042318?language=en_US

if there is a firmware to download?

can you please show me where to download?

I have license for switch but can not see

Recovery file found in Sophos Central > Protect Devices > Switches > Download recovery image

ok, found de recovery file.

I will try recovery first

I have recovered the switch the recovery image and could register the switch to Sophos Central

Thanks PhilippRusch  and LuCar Toni  for your support

thanks LuCar Toni 

Sophos has updated the manual for TFTP recovery after I have contacted them.

Te first time the recovery worked as expected but now for the second time it is not working.

Because there is no console ports I think I have to replace this switch trough RMA

There is a reset button but think this is not working? Maybe you have more info about this reset button?

What I wanted was to move the mnagement interface to another port with VLAN

This is what I changed:

Management to VLAN 100 in DHCP
Port 2-10 untagged VLAN 100

Still traffic passing trough switch but no Web interface and no ping

thanks LuCar Toni 

you have the answer.

strange there is no document about this  192.168.1.00 UDP 69

the document has been updated by Sophos

Found the info about reset button in Sophos Operating Instructions

Reset Button:

Press and hold the reset button for 7 seconds to reset the switch to the factory default settings. All configuration including the login password will be reset.

Found the info about reset button in Sophos Operating Instructions

Reset Button:

Press and hold the reset button for 7 seconds to reset the switch to the factory default settings. All configuration including the login password will be reset.