When router is connected to a switch internet speed deteriorates

nfpa1600

Prominent
Sep 29, 2017
2
0
510
Hello,

I have a D-Link (AC-1900) router with current firmware and a Asus GX-D1241-V4 24-port Gigabit Switch (unmanaged) on a network that is Cat 6 cable. When I connect the router to the switch my internet (wireless and wired) becomes slow, when i disconnect the switch the internet returns to normal speeds. Specifically when the the router (which is connected to a cable modem) is not connected ping tests indicate a 15 -18 ms response time on wireless internet connection. When I connect the router to the switch via a lan cable (cat 6) the ping speed remains constant then suddenly degrades to a ping of 500+ms.

I have also hooked a laptop to the lan ports of the router and check speeds when not connected to the switch. Speeds remain normal (13-18ms).

The switch performs well and while the slow internet is happening I have tested network speeds by moving 40 gig files from place to place and I get very good speeds (150 Megabytes a seconds). So the conflict seems to be between the router and switch!

I have rebooted the switch and router in a number variations and this solves the problem for a couple minutes then the problem returns .... I have changed cables, ports, my bubble gum and nothing seems to work.

I have dealt with support on both products and they have come up blank..
 
Solution
What happens if you unplug all 10 devices and leave just the switch connected to the router.

A unmanged switch is really stupid it just copies data from one port to another. Almost all switches are considered non blocking or wire speed. This means there is no detectable delay.

If it does this with a just one cable connecting the switch to the router and nothing else it almost has to be some kind of defective switch.....not that I can think of a way even a failed switch can cause half a second of delay.
So does it do this when you have just the switch plugged in or are there device plugged into the switch.

I could see packet loss but increase ping time is strange. Ethernet does not retransmit data like wireless it just discards damaged data.

I would normally guess some ip conflict but if it does it with just the switch connected that would not really be possible since the switch is unmanged. Things like loops also cause issues like this and would happen if you plugged 2 port together on the switch....unless it is running spanning tree by default.
 

nfpa1600

Prominent
Sep 29, 2017
2
0
510
Hello Bill001g

The problem only occurs when the router is connected to the switch. The router is only connected by one cable to the switch and I have tried every port on the router with the same outcome. I don't think its a loop as there is just one cable and the switch is not detecting a loop.

In the switch about 10 ports are used to connect a variety of devices (2 NAS drives, TV, DVD, Two media players etc ....).

I am not sure what a spanning tree is but would be willing to learn and run what ever is needed for a diagnostic.

 
What happens if you unplug all 10 devices and leave just the switch connected to the router.

A unmanged switch is really stupid it just copies data from one port to another. Almost all switches are considered non blocking or wire speed. This means there is no detectable delay.

If it does this with a just one cable connecting the switch to the router and nothing else it almost has to be some kind of defective switch.....not that I can think of a way even a failed switch can cause half a second of delay.
 
Solution

TRENDING THREADS