Problems using Router as Switch/AP

[FoXtroT]

I'm having problems turning my TP-Link TD-W8980 into a switch and AP on my network.

My main router is the Draytek Vigor2830Vn with an IP of 192.168.1.1 and a range of 192.168.1.100/50

I put the TP-Link in the room I need a switch/AP in, give it an IP of 192.168.1.2 and disable DHCP. Connect it to the rest of the network, ensuring nothing is connected to the WAN port.

Clients using the switch/AP are able to see and interact with the rest of the network but are unable to connect to the internet.

What could be going wrong? According to countless Google searches, I've been doing everything right.

 

[sajunky]

I guess DHCP is disabled on WAN interface, not a LAN interface. Same applies to default gateway, it should be blank and IP address. On some routers there is one switch to disable WAN interface completely. Do you connect both devices by Ethernet cable LAN to LAN port?

 

[BigBear]

Your main dhcp router needs to be able to assign an address within the defined ip range.

192.168.1.2 doesn't seem to be in that range.

IP Range correct ?

Network: 192.168.1.0/24
(Class C)
Broadcast: 192.168.1.255
HostMin: 192.168.1.1
HostMax: 192.168.1.254
Hosts/Net: 254

 

[SauRoNZA]

Don't use the WAN port to connect to it.

Must be connected on one of the LAN ports.

Also make sure the default gateway is configured.

 

[infscrtyrisk]

Your main dhcp router needs to be able to assign an address within the defined ip range.

192.168.1.2 doesn't seem to be in that range.

IP Range correct ?

Network: 192.168.1.0/24
(Class C)
Broadcast: 192.168.1.255
HostMin: 192.168.1.1
HostMax: 192.168.1.254
Hosts/Net: 254

Have to agree with your approach, considering that there are only 32 bits in a IP v4 address, a /50 sounds a little suspect... perhaps for very small values of 50...

 

[Hamish McPanji]

Have to agree with your approach, considering that there are only 32 bits in a IP v4 address, a /50 sounds a little suspect... perhaps for very small values of 50...

I think he is allowing DHCP to assign addresses from 1.100 to 1.150

 

[Hamish McPanji]

Can you send as a pic of the IP address assignment on a PC that is connected to that router?

 

[FoXtroT]

The LAN Page of the Draytek, the main router



LAN Page of my TP-Link which I want to use as a switch.


The Main Status page of the TP-Link. Note I am unable to delete the WAN connection nor can I disable it on the router itself but can confirm nothing is plugged into the WAN port.



The reason I put the TP-Link outside the DHCP range was because that is what all my google searches led me to believe and sources included TP-Link themselves. They all say the secondary router must be on the same subnet but not in the DHCP range for it to work. For completeness sake I have tried putting it in the DHCP range but that doesn't work either.

EDIT: Oh, the one Laptop that is connected to that second router has the main router as its default gateway and even has the ISPs DNS servers. The adapter details in windows even shows it has internet access but the laptop nor any wireless device connected to that AP is able to access the internet.

 

[sajunky]

The reason I put the TP-Link outside the DHCP range was because that is what all my google searches led me to believe and sources included TP-Link themselves. They all say the secondary router must be on the same subnet but not in the DHCP range for it to work. For completeness sake I have tried putting it in the DHCP range but that doesn't work either.

You are doing well, there is no other way to do it correctly. Disregard other posts regarding DHCP.

EDIT: Oh, the one Laptop that is connected to that second router has the main router as its default gateway and even has the ISPs DNS servers. The adapter details in windows even shows it has internet access but the laptop nor any wireless device connected to that AP is able to access the internet.

According to the first picture, Draytek do not receive DNS addresses from ISP, so any DHCP client do not receive it either. It can be a problem with your ISP. What happen if you plug laptop directly to the Draytek?

This laptop may have some manual DNS setting. Go to the adapter properties and restore automatic IP and DNS assignment. Then open command line and post output of the "ipconfig /all" (remove any MAC numbers).

For testing put Google DNS IP's (8.8.8.8 and 8.8.4.4) on the Draytek and see whether Internet starts flowing.

It may be not important, but TP-link is still trying to activate WAN interface. You can disable IPv6 on this device to cool it off.

 

[FoXtroT]

You are doing well, there is no other way to do it correctly. Disregard other posts regarding DHCP.

According to the first picture, Draytek do not receive DNS addresses from ISP, so any DHCP client do not receive it either. It can be a problem with your ISP. What happen if you plug laptop directly to the Draytek?

This laptop may have some manual DNS setting. Go to the adapter properties and restore automatic IP and DNS assignment. Then open command line and post output of the "ipconfig /all" (remove any MAC numbers).

For testing put Google DNS IP's (8.8.8.8 and 8.8.4.4) on the Draytek and see whether Internet starts flowing.

It may be not important, but TP-link is still trying to activate WAN interface. You can disable IPv6 on this device to cool it off.

Draytek is receiving DNS from ISP, just shown in the router's WAN page not the LAN. I'm typing this from my PC which is connected into the Draytek via a switch and I seem to be the only one in the house with internet access. Another Laptop, also connected to the Draytek via the same switch, is also now unable to connect to the internet. I'm completely baffled.

All devices have been set to obtain IP address and DNS automatically in their respective adapter settings.

 

[FoXtroT]

You know what, not to worry everyone. Clearly the Draytek is a bit too technical for my level of understanding. I swopped the two routers around and everything is working fine now.

Would have liked to have the Draytek as my main one as it had some interesting features, but alas I would rather not get lynched by my family for not having internet.

 

[Hamish McPanji]

If you do decide to switch them back. You need to check on the client pc if the DNS addresses are gateway addresses are given by the draytek assigned IP address.

As an option, fill in the Google DNS addresses on the DNS settings on the draytek

 

[infscrtyrisk]

I think he is allowing DHCP to assign addresses from 1.100 to 1.150

Looking at the screenshot of the Draytek, the DHCP server will hand out IP addresses in the range 192.168.1.100 to 192.168.1.149, so now I understand the "/50" -- problem is that its Cisco notation for the subnet mask.

@OP: If I were you I'd check the client side config as Hamish indicated, and also maybe check out the switch between the TP-Link and Draytek, ensure that it's running latest firmware & set it to factory defaults, might be a strange VLAN config or some other remnant of the past that's haunting you. Also, the TP-Link should be set to relay the DHCP from the Draytek (so I'm not sure how the client is getting the network info right now).

 

[irBosOtter]

Looking at the screenshot of the Draytek, the DHCP server will hand out IP addresses in the range 192.168.1.100 to 192.168.1.149, so now I understand the "/50" -- problem is that its Cisco notation for the subnet mask.

@OP: If I were you I'd check the client side config as Hamish indicated, and also maybe check out the switch between the TP-Link and Draytek, ensure that it's running latest firmware & set it to factory defaults, might be a strange VLAN config or some other remnant of the past that's haunting you. Also, the TP-Link should be set to relay the DHCP from the Draytek (so I'm not sure how the client is getting the network info right now).

View attachment 468433

DHCP relay is only used if the DHCP server is sitting on the other side of the WAN connection in a different subnet, it will try to relay DHCP requests over the WAN port which is not in use here. Most routers will say "disable NAT on WAN port" in order for DHCP relay to work.
Seeing both routers are on the same /24 network clients should get a IP from any active DHCP server on that /24 network

I had the same issue last week when I got fibre installed, after a few hours it just started working, not sure why. Setup DHCP on Fortigate, set DHCP off on TP-Link D7. Nothing wanted to get a IP unless plugged directly into the fortigate port. Then moved DHCP to TP-Link, all works fine, then back to fortigate. Still nothing. Then after a few hours it just started working, rebooted all devices a few times during that time.
Also tried that DHCP relay option but new it would not work as the server is in the same range already so no need to relay anywhere, so switched it off again. If I now enable relay it stops working.

If you setup a IP-helper address on a cisco router to a DHCP server on the same subnet it causes major issues, as the DHCP server then get a request from the client and from the router and that screws things up a bit

 

[infscrtyrisk]

DHCP relay is only used if the DHCP server is sitting on the other side of the WAN connection in a different subnet, it will try to relay DHCP requests over the WAN port which is not in use here. Most routers will say "disable NAT on WAN port" in order for DHCP relay to work.
Seeing both routers are on the same /24 network clients should get a IP from any active DHCP server on that /24 network

True, they are on the same broadcast domain, so it should work. But as you've stated, implementations differ from router to router to firewall, as well as firmware versions. In my own TP-Link TD-W8980 implementation it only works with it enabled.

 

[irBosOtter]

True, they are on the same broadcast domain, so it should work. But as you've stated, implementations differ from router to router to firewall, as well as firmware versions. In my own TP-Link TD-W8980 implementation it only works with it enabled.

Yeah maybe he should try it then, never know, might work for him as well