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Mikhail Faifman

Firmware upgrade --> (SG 300-28P)

Should i be concerned doing the firmware upgrade remotely? I.e. remote to a local workstation and connecting to SG 300-28P from that workstation over LAN and doing firmware upgrade using WebGUI (Google Chrome)?

I've done the multiple upgrades on these switches this way and never had an issue.

However, Release Notes for have some notice regarding boot image and I am concerned that configuration can be lost after the upgrade and if this is the case I'd be screwed since I won't be able to get on the switch to load the custom config after the fact.

Anyone who's done this upgrade please report if your configuration settings were left in place after the upgrade to

Tom Watts

Hi Mikhail, it is never recommended to remotely upgrade software unless you have someone on site to resolve issues or a form of out of band management.

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-Tom Please mark answered for helpful posts

I updated my SG500 remotely and it worked just fine.

Took a while to boot back up but I suppose that is because of the flash upgrade it said it was going to do.

I left my console terminal open on the machine I remoted into.

When I was able to reconnect, I reviewed the console terminal and all seemed normal.

Config was fine.

Hello *,

just an additional question on how to do the firmware upgrade to

After upgrading the boot code do I first have to reboot the switch before copying and applying the firmware upgrade to the switch?

Or is it essentional NOT to reboot and to copy and apply the new firmware image file immediately after I've copied the new boot code file to the switch?

Best regards


Hello Matthias, I've just upgraded my Sg300-28, everything is ok.

Steps: update boot loader (via scp) reboot, update firmware (via http) reboot, update language (Italian, in my case). Previous configuration was restored correctly, and automatically. I have only an issue with DHCP server, which seems to be not working anymore... I'll try to test a little more...


Did you find a solution to DHCP problem you mention ??.

Any other issue related to the firmware upgrade ?.


Hello Armando, yes I found that disabling "Option 82" under

- IP Configuration

- IPv4 Management ...

- DHCP Snooping/Relay

- Properties

actually fixes the issue, and DHCP is now working correctly.




Hi Mikhail,

One issue we have found is that going from to causes our Trunk ports to revert to a single VLAN (the default VLAN).  We tested the upgrade remotely on a switch about 10 miles away and discovered this.  We now will have to do the upgrades onsite at each location and repair the trunk port after each upgrade.



Cameron hi,

Interesting input about loss of VLAN configuration while upgrading version. Is this the 1st time you see this issue, or does it happen also during regular reload of the switch?

Also - some question which can may provide additonal informaiton on issue  (if you can provide these):

1) Did the issue happen on a port connected to another switch (an uplink port)? - If so what is the neigbor switch type?

2) would it be possible for you to to provide running and startup config before and after reload (of course without security sensative details).

3) Can you provide outputs of show CDP neighbors (detail)  before and after reboot?



Hi cfrasnelly, can you give any more details about your upgrade?

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-Tom Please mark answered for helpful posts

Out of 5 switches that we have installed so far, 4 of them have removed all tagged VLANS from our trunk ports and left only the default VLAN on the port.  This is quite the inconvenience for us since we have17 switches to upgrade and most of them are 25+ miles away!

We have followed the same procedure so we're not sure what the determining factor was for the 1 switch that was left intact.  If we figure it out we will post a solution here.

Can I call you? I really want to see this.

Please email me at

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-Tom Please mark answered for helpful posts
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