A maddening network problem

My laptop (Win 10) can connect to my LAN using two configurations:

Wifi (most of the time):
Laptop -> WAP (TP-Link AP200 with DHCP disabled) -> Switch#1 -> Router

Ethernet:
Laptop -> Switch#2 -> Router

In both configurations I can access the internet just fine. I can also access my server which is permanently connected to the router.

However I can only access my printer and my desktop over Ethernet. Both of those are connected via switch#3 to the router. I can't even ping them from laptop when using wifi, I just get 'destination host unreachable'.

When using the desktop it too can access the internet just fine but refuses to acknowledge the existence of the laptop. To be honest this isn't a big deal most of the time but today I wanted to print something and wasted half an hour trying to get it working until I remembered to try connecting over Ethernet.

For what's worth here are the (slightly redacted) outputs from ipconfig/all:
IPConfig Ethernet:

Windows IP Configuration

Host Name . . . . . . . . . . . . : LAPTOP-SRL4BAVA
Primary Dns Suffix . . . . . . . :
Node Type . . . . . . . . . . . . : Hybrid
IP Routing Enabled. . . . . . . . : No
WINS Proxy Enabled. . . . . . . . : No
DNS Suffix Search List. . . . . . : idnet.com

Ethernet adapter Ethernet:

Connection-specific DNS Suffix . : home.gateway
Description . . . . . . . . . . . : Realtek PCIe FE Family Controller
Physical Address. . . . . . . . . : EC-8E-B5-30-3A-80
DHCP Enabled. . . . . . . . . . . : Yes
Autoconfiguration Enabled . . . . : Yes
IPv4 Address. . . . . . . . . . . : 192.168.1.110(Preferred)
Subnet Mask . . . . . . . . . . . : 255.255.255.0
Lease Obtained. . . . . . . . . . : 30 June 2018 15:38:11
Lease Expires . . . . . . . . . . : 01 July 2018 15:38:10
Default Gateway . . . . . . . . . : fe80::6203:47ff:fe39:875a%19
192.168.1.254
DHCP Server . . . . . . . . . . . : 192.168.1.254
DNS Servers . . . . . . . . . . . : 2a02:390:1::64:6e73
2a02:390:2::64:6e73
192.168.1.254
NetBIOS over Tcpip. . . . . . . . : Enabled
Connection-specific DNS Suffix Search List :
idnet.com

Wifi:

Windows IP Configuration

Host Name . . . . . . . . . . . . : LAPTOP-SRL4BAVA
Primary Dns Suffix . . . . . . . :
Node Type . . . . . . . . . . . . : Hybrid
IP Routing Enabled. . . . . . . . : No
WINS Proxy Enabled. . . . . . . . : No
DNS Suffix Search List. . . . . . : idnet.com

Wireless LAN adapter WiFi 4:

Connection-specific DNS Suffix . : home.gateway
Description . . . . . . . . . . . : 802.11ac Wireless LAN Card
Physical Address. . . . . . . . . : 80-3F-5D-20-EF-85
DHCP Enabled. . . . . . . . . . . : Yes
Autoconfiguration Enabled . . . . : Yes
IPv4 Address. . . . . . . . . . . : 192.168.1.101(Preferred)
Subnet Mask . . . . . . . . . . . : 255.255.255.0
Lease Obtained. . . . . . . . . . : 30 June 2018 14:56:34
Lease Expires . . . . . . . . . . : 01 July 2018 15:42:01
Default Gateway . . . . . . . . . : fe80::6203:47ff:fe39:875a%13
192.168.1.254
DHCP Server . . . . . . . . . . . : 192.168.1.254
DHCPv6 IAID . . . . . . . . . . . : 427835229
DHCPv6 Client DUID. . . . . . . . : 00-01-00-01-1F-51-57-C0-EC-8E-B5-30-3A-80
DNS Servers . . . . . . . . . . . : 2a02:390:1::64:6e73
2a02:390:2::64:6e73
192.168.1.254
NetBIOS over Tcpip. . . . . . . . : Enabled
Connection-specific DNS Suffix Search List :
idnet.com

I haven't done anything special to the laptop - I just let Windows manage things. For what it's worth the server is on a fixed address of 192.168.1.11 and as noted is always accessible :-/

I'm assuming it's something to do with the WAP but don't understand why the server is always available since that kinda works against that theory. How can that host always be present when other hosts are only present over Ethernet?

Edited by Andrue (Sat 30-Jun-18 15:53:40)

dumb switches...ie without management interfaces?

firewall software on windows machines?

Dhcp server?

dns server?

Edited by ian007jen (Sat 30-Jun-18 16:58:23)

Windows IP Configuration

Host Name . . . . . . . . . . . . : LAPTOP-SRL4BAVA
Primary Dns Suffix . . . . . . . :
Node Type . . . . . . . . . . . . : Hybrid
IP Routing Enabled. . . . . . . . : No
WINS Proxy Enabled. . . . . . . . : No
DNS Suffix Search List. . . . . . : idnet.com
.................................................
I might be wrong but I think that the above should have a Primary DNS Suffix and that IP Routing Enabled should be "Yes".?

In reply to a post by ironman12345:

I might be wrong but I think that the above should have a Primary DNS Suffix and that IP Routing Enabled should be "Yes".?

From reading up on it I think that would just turn my laptop into a router. Primary DNS suffix being incorrect wouldn't (I don't think) explain why I can't ping the desktop using its IP address.

But thanks

In reply to a post by ian007jen:

dumb switches...ie without management interfaces?

Yup, three different models, #1 is a new(ish) TP-Link, #3 is a very old TP-link and #2 is some no-name £10 jobby from Amazon

firewall software on windows machines?

Kaspersky on desktop, server and laptop.

Dhcp server?

dns server?

My Billion AC1600. Under DHCP it lists everything on the LAN.

In reply to a post by Andrue:

In reply to a post by ironman12345:

I might be wrong but I think that the above should have a Primary DNS Suffix and that IP Routing Enabled should be "Yes".?

From reading up on it I think that would just turn my laptop into a router. Primary DNS suffix being incorrect wouldn't (I don't think) explain why I can't ping the desktop using its IP address.

But thanks

Yep sorry , but if the laptop has an IP address ,which it has and is connected to the router [Ethernet] then I cannot see any reason why it does not connect in wifi.?
It looks like a WAP problem.

In reply to a post by ironman12345:

In reply to a post by Andrue:

In reply to a post by ironman12345:

I might be wrong but I think that the above should have a Primary DNS Suffix and that IP Routing Enabled should be "Yes".?

From reading up on it I think that would just turn my laptop into a router. Primary DNS suffix being incorrect wouldn't (I don't think) explain why I can't ping the desktop using its IP address.

But thanks

Yep sorry , but if the laptop has an IP address ,which it has and is connected to the router [Ethernet] then I cannot see any reason why it does not connect in wifi.?
It looks like a WAP problem.

Yeah. But some good (if puzzling) news: It's all working now. I sat down this evening to thrash it out and decided to look at the WAP UI. I noticed it had a ping tool so I gave it the desktop ip address. After a delay of a second or more it suddenly started reporting replies. So I tried again with my laptop and now it can see the desktop.

One thing I will say is that both the printer and the desktop spend most of their time powered down. Although why that should cause an issue on the LAN I don't know. It also seems weird that the nature of the issue is a kind of 'partitioning' of the network :-/

Anyway for now things are back to normal so it will have to remain a puzzle :-/

Great! glad it is at least working now.
About the LAN though personally I can only think of QOS delay. But no matter.

Can any other device connected to your WAP ping your desktop or printer?

Could you connect the WAP direct to your router?

Next time it happens I'll test that theory. I'm assuming other devices will have the same problem. It seems to me that it's the WAP being slow to notice newly added devices. Although that's odd because my understanding is that new devices should advertise themselves so it should be automatic.