Just a quick post in the hope that this helps somebody else in the future. I’ve recently been re-configuring my home lab and decided to temporarily remove all VLANs until I’d decided on the new architecture. I currently use HP 1810G switches (1810G-24 to be specific) in my network and whilst not as good as some of the higher end kit I’ve got they’re very low power and affordable for a home or small business.
When removing the VLANs I simply removed all VLANs from the web interface on both switches leaving just a “VLAN 1” as the default VLAN for management. I verified each port’s configuration and noticed that they were all labelled as being on the same VLAN and all labelled as “untagged” indicating that everything should have been able to immediately talk. I also removed VLAN tags from within my ESX infrastructure.
Initially things seemed to work fine but after a whilst I noticed some of the new equipment I was connecting was unreachable – pings did not respond and there were no packets coming from them when looking at network packet traces. As these were initially hardware devices like PDUs and my UPS I started to question whether some of the devices I’d purchased were faulty. The issue then started to occur with my storage server after re-cabling.
It turns out that despite the UI stating everything is on the same VLAN and untagged that isn’t the case. All the ports were as they’d previously been configured (which also explains why most things carried on working fine) rather than untagged VLAN 1.
If you delete a VLAN on the HP 1810G switches make sure you do the following extra steps:
- Go to the default VLAN that the port now needs to be on (it should be showing U for that port)
- Click the port until it becomes “T” for tagged
- Repeat for any other ports
- Save the changes ignoring any warning
- Put the port(s) back to “U” for untagged
- Save the changes again
Voila nice and easy just forcibly save the same settings again by toggling the VLAN and then setting it back and you should be able to ping your devices on a HP 1810G again.