Slow WAN Speed

[Raziel]

The details of my problem are as follows:
1- My GT-AC5300's WAN port is connected via a CAT 6 cable to another router’s LAN port (LinkSys WRT32x)
2- The WAN LED on my GT-AC5300 is white (Indicating a successful WAN connection)
3- My Gaming PC is connected to the GT-AC5300 using LAN port 1 using a CAT 6 cable
4- My Internet speed is fast on the LinkSys WRT32x (~100 Mbps down, and ~30 Mbps up). On the GT-AC5300 however, it's slow most of the time (4-10 Mbps), and the only thing that fixes it is if I unplug/replug the CAT 6 cable connected to the WAN port repeatedly before it works well again.

Additional Details:
1- My GT-AC5300 router is configured with a static IP so it can connect to LinkSys WRT32x. The static configuration is as follows:

IP Address: 192.168.1.229
Subnet Mask: 255.255.255.0
Gateway Address: 192.168.1.1 (Same as the IPv4 LAN address of the WRT32x)
Primary DNS: 192.168.1.1 (Same as the IPv4 LAN address of the WRT32x)
Secondary DNS: 8.8.8.8

2- There is no IP conflict on my network
3- If I ping the LinkSys WRT32x router (Acting like the gateway), I get Request Timed Out every ~10 successful pings
4- The WAN port’s pins look good

Things I tried:
1- Restoring the router to factory settings
2- Reflashing the firmware with the latest firmware build 3.0.0.4.386_42643-g16dc577 (I also tested all the older firmwares for the router)
3- Tried to connect the GT-AC5300's WAN port to another router (My Asus 4G-AC68U)
4- Different Cat 6 cables
5- Tested the Internet on a laptop that's connected to a different LAN port on GT-AC5300
6- Tested the Internet using my phone over Wi-Fi

Not only that, even the Admin Consoles of the different routers that I tried to connect to my GT-AC5300's WAN port were either timing out, or painfully slow to navigate. The only thing that would fix my problem is if I unplug/replug the CAT 6 cable from my WAN port many many many times.

The System log shows the following when the problem is happening:

When the problem happens, I can see the following in the System Log:

Nov 20 19:45:35 kernel: FPM Pool 0: invalid token 0x003ff000 freed
Nov 20 19:45:41 kernel: FPM Pool 0: invalid token 0x003ff000 freed
Nov 20 19:46:02 kernel: FPM Pool 0: invalid token 0x003ff000 freed
Nov 20 19:46:07 kernel: FPM Pool 0: invalid token 0x003ff000 freed
Nov 20 19:46:10 kernel: FPM Pool 0: invalid token 0x003ff000 freed
Nov 20 19:46:10 kernel: FPM Pool 0: invalid token 0x003ff000 freed
Nov 20 19:46:10 kernel: FPM Pool 0: invalid token 0x003ff000 freed
Nov 20 19:46:10 kernel: FPM Pool 0: invalid token 0x003ff000 freed
Nov 20 19:46:11 kernel: FPM Pool 0: invalid token 0x003ff000 freed
Nov 20 19:46:11 kernel: FPM Pool 0: invalid token 0x003ff000 freed
Nov 20 19:46:13 kernel: FPM Pool 0: invalid token 0x003ff000 freed
Nov 20 19:46:13 kernel: FPM Pool 0: invalid token 0x003ff000 freed
Nov 20 19:46:19 kernel: FPM Pool 0: invalid token 0x003ff000 freed
Nov 20 19:46:20 kernel: FPM Pool 0: invalid token 0x003ff000 freed

When the problem is fixed (By unplugging/replugging the Cat 6 cable to the WAN port many many many times), I stop seeing the above logs.

I contacted Asus’ customer support, and the only replies I got from them are some generic messages asking me to reflash the firmware, although I had already mentioned to them that I’ve already done that.

Please help.

 

[ColinTaylor]

The WAN socket may be damaged. Enable Dual WAN (in Fail Over mode) and assign an Ethernet LAN port as the Primary WAN and use that instead.

EDIT: Also make sure QoS is disabled.

 

[Raziel]

Colin, I appreciate the prompt reply.

I tried your suggestion, and while it works, it seems to have the following limitations:
1- The Ethernet port isn’t as configurable as the WAN port (e.g: I can’t use PPPoE on it if I want to).
2- The WAN LED indicator will be off in this mode.

Another thing that I missed mentioning, is that when the router is working well, rebooting it from the admin console would re-induce the issue. (i.e Without making any physical contact with the router, which could wiggle the cable connected to the WAN port).

 

[airgap]

Why are you plug the LAN cable to the WAN port of the GT-AC5300? Those have plenty other LAN-ports. Just use one of them and see what happens.
You don't have to configure the ports to be "WAN"-port! Your GT-AC5300 just should act as a switch or bridge and send the packets for the internet to the main router which is your Linksys.

Besides that a good way of troubleshooting would be to have the log view of both routers at the same time. (may be ignore the fpm pool messages).