The manufacturer TP-Link has a family of products called “TP-Link Deco” which are its WiFi Mesh systems, these WiFi Mesh systems can only be managed through an application for mobile devices, it does not have a graphical user interface via web where to configure their equipment in an advanced way, so that advanced users will miss much less options that we do have in their Archer routers. The TP-Link Deco make use of a function called ” Smart DHCP ” when we activate the access point (AP) mode that can wreak havoc on your local home network . Today in this article we are going to explain this problem that a reader has had, and that after different tests we have seen how hundreds of users are also affected.
What does it mean to use the TP-Link Deco as AP?
TP-Link Deco WiFi Mesh systems can be used in two very different ways, something that is common to other manufacturers such as ASUS, D-Link or NETGEAR. The two modes of operation are as follows:
- Router mode : the WiFi Mesh system will manage the entire network completely, and it will have the public IP on the Internet WAN interface. We will have a DHCP server, NAT, QoS, parental control and the rest of the functionalities.
- AP mode : the WiFi Mesh system will only provide the WiFi user with WiFi roaming and band-steering, we will not have NAT, QoS, parental control or DHCP server, because all this will be handled by the main network router.
Although it is always advisable to use the router mode in WiFi Mesh systems, so that they fully manage the entire network, in those cases where the operator’s router does not allow to put it in bridge mode, or in single-user mode, the best option is to configure this type of WiFi Mesh systems in AP mode, so that the operator’s router continues to manage the entire network, except the WiFi connection. By all of us it is known that the WiFi routers of the operators do not provide us with good coverage or good speed.
Buying a WiFi Mesh system to have different nodes distributed throughout our home is something that many users do, to improve the weak point of the operator’s router: the WiFi. In addition, we will have a great user experience thanks to WiFi roaming to go from one node to another without interrupting the wireless connection, in addition to having band-steering to go from one frequency band to another.
What is the problem of the TP-Link Deco in AP mode?
A reader decided to buy a TP-Link Deco to improve the WiFi network at home, since the main router is the Orange Livebox Fiber. When put in access point mode, the TP-Link Deco should be completely transparent and be managed by the main router, which uses the default subnet 192.168.1.1, with its corresponding DHCP server that indicates the IP addresses to the different clients, and also the default gateway to access the Internet, which is the same IP of the router, as always. After a few days with this setup and working fine, she noticed that some of her devices would suddenly lose connection to the Internet and were assigned another IP address from a completely different range. After different tests, we saw that the problem was with the TP-Link Deco in AP mode.
It seems that all TP-Link Deco models make use of a feature called ” Smart DHCP “, this function consists of verifying if there is a DHCP server in the local network, if for some reason this process fails, or takes a while more than normal, then, and automatically, the TP-Link Deco decide to activate its own DHCP server using a completely different subnet, and providing new IP addresses to some or all of the clients on the network, leaving no Internet connection to various devices.
While some devices maintain the address of the private network created by Livebox Fibra, other clients automatically take the IP address provided by the TP-Link Deco. Devices with IPs from the Livebox Fibra range will continue to have an Internet connection without any problem, however, those from the TP-Link IP will not, because the IP address of the default gateway will not be the Livebox Fibra, but the IP address itself. TP-Link Deco, which does not have the Internet connection.
Example:
- The Livebox Fibra router has the subnet 192.168.1.0/24 with the DHCP server from 192.168.1.2 to 192.168.1.200. All clients get IP with the default gateway to 192.168.1.1 which is the router.
- The TP-Link Deco are in AP mode, they should never activate their own DHCP server, because this would cause address duplication problems (if they are in the same range) or directly no connection to the Internet or to the local network (if they are in different range). In this case, it uses the 192.168.78.0/24 subnet, therefore, if a client obtains an IP address from Smart DHCP, it will automatically be without an Internet connection.
How can I solve this problem?
The only way to fix this problem is to turn off all TP-Link Deco and the affected devices , turn on the affected devices to get the IP from the Livebox Fibra DHCP server, and then turn on the TP-Link Deco. It is not enough just to turn off a TP-Link Deco that acts as a DHCP server, because the rest of Deco will detect it and decide to self-configure themselves as a DHCP server, going from one to another until only one remains. For this reason, it is necessary to turn off all the Deco that we have on the network.
This problem affects both the devices connected via WiFi as well as the devices connected via cable , although there are some devices that will keep the IP within the correct network, of course, if you put a fixed IP on each and every one of the computers you will not have no problem, but not normal in a home environment. The problem will happen again sooner or later, so it is not a definitive solution.
If you change the subnet of the main router and make it match the Deco, you must bear in mind that you could have 2 computers with the same IP address on the network, that is, you will have an IP address conflict , because one computer will be “hanging” DHCP server of the router, and other equipment of the DHCP server of TP-Link Deco.
If you have not yet purchased a TP-Link Deco, our recommendation is that you buy other WiFi Mesh systems, either from ASUS, D-Link or NETGEAR. In this article you have in-depth analysis of the vast majority of models on the market, such as the D-Link COVR-1103 which is one of the best in quality / price ratio, you also have the ASUS ZenWiFi CD6 that work really well and they have hundreds of configuration options, including a very advanced OpenVPN server. You can also buy the NETGEAR Orbi RBK23 which is high-end and will provide you with outstanding performance.
You can read the opinion of other users about these TP-Link Deco on Amazon , and also access their official forums where there are many complaints .