Hello,

I am starting this new thread following from the previous thread which you can find by following this link: https://community.tp-link.com/en/business/forum/topic/277522

Firstly, I'd like to explain my situation that I wanted a configured & manageable network with multiple VLANs, so I went ahead with purchasing the TL-SG2016P and TL-SG2428P Smart Switches to replace the standard network switches which did not have Omada support. I have since had these switches installed and commissioned into my Omada Cloud Controller with the default gateway router being the ER605.

Pretty much my network configuration is almost exactly the same as what @dapL has mentioned in the other thread but have adapted this as I have a domain controller environment setup which includes domain joined devices on both wired and wireless networks, so therefore the my VLAN configuration is being configured to split the network into three with one being for the domain joined devices only, the other for personal use and a secure network for guests only. All three of these separate networks have different VLAN interfaces just to make it more secure and to tidy up from the configuration point of view.

My network configuration is setup as follows:

• VLAN1 - TP-LINK Infrastructure (Routers, Switches, EAPs)
• VLAN10 - Core Network (Domain Servers, NAS, CCTV etc)
• VLAN20 - Domain Wired Devices
• VLAN30 - Domain Wireless Devices
• VLAN40 - Third Party (CCTV Cameras, Smart IoT devices etc)
• VLAN50 - Private Wired/Wireless Devices (Personal phones, tablets, laptops etc)
• VLAN60 - Guest Wireless

So far currently I have VLAN1, VLAN40, VLAN50 & VLAN60 all connected to ER605 VPN Router as their DHCP server. The other VLANs include VLAN10, VLAN20, VLAN30 are all connected via a DC Server which have DHCP installed.

This is where it gets a bit technical...

I have added a DHCP Relay onto two my smart switches by giving them as static IP address for each of the VLAN interfaces (don't know why this has to be done like this but at least it works) and then apply the DHCP Relay to point to my DC server so that the following VLAN10, VLAN20, VLAN30 devices gets an IP address from the DC server rather than the ER605 and then the rest of the network gets their IP addresses from ER605 DHCP gateway.

My concern at the moment is that if the DC server stops working or have shut down, then all the domain joined clients and other servers will stop working as it is no longer receiving DHCP from the server. Should the DC server start up again, it should hopefully start giving out IP addresses again dependent on the switches I have configured this to and so I am wondering if there is any way that either the switches or the ER605 can temporarily give out IP addresses but bearing in mind that it may not know the reservations I have set it to and have a feeling it will not work correctly as it will just randomly give a IP address to a NAS box for instance unless I need to look at configuring the static IP addresses for each of the core devices setup on the server side. I'm guessing what I'm talking here is about configuring a 'failover' solution.

Another concern is that very recently when I went to switch off the TL-SG2016P smart switch so I can install a UPS battery backup system and when I switched the smart switch back on, for some reason it is not giving out IP addresses from the DHCP Relay on my DC server (reiterating the VLANs as 10, 20 and 30) and I'm assuming it did not pick up the connection afterwards and weirdly it has ignored my VLAN interface configurations, so a quick fix I did was just to disable the affected VLAN interfaces from the affected switch, apply and then re-enable them again which resolved this weird issue. So I don't know what has happened there but assuming this might be just a glitch with the firmware.

Any suggestions & assistance would be greatily appreciated.