Need diagnostic help/recommendations


Occasional Visitor
I'm frustrated by my own ignorance & need help. I don't know how/what to do to identify & rectify an annoying Internet connection issue I've been experiencing.

I have two desktop computers connected directly to LAN ports on my router via Cat6 Ethernet cable. All Ethernet ports involved are 1000/1000 Mbps.

While on the Internet on either of these two computers (using Google Chrome on both), everything "freezes": Sometimes for 15-20 seconds, other times for 2-3 minutes. (I don't really know whether there's a similar issue with WiFi, as that is used mostly really just by cellphones & I think those jump to cell service when WiFi isn't working well).

I would like to know what software tools &/or testing device(s) I need (& how & in what order to use them) to figure out what's causing these intermittent "freezes" & how to remedy them.

It seems like these problems could be arising from different "places" on my network, including:

1. Poor signal into the ONT (provider signal issue);

2. Something IN the ONT;

3. Bad CAT6 cable between the ONT & the router;

4. A problem in my router (maybe I've screwed up some setting?);

5. Bad CAT6 cables between the router & the computers;

6. A hardware issue inside both computers (two @ once seems unlikely); or

7. A software issue in both computers (bad drivers, software interference, possible malware, etc.).

FWIW - I ck'd & my 64bit Windows 10 OS is up to date. No malware reported by Hitman Pro & Malwarebytes scans.

After having ck'd the above, I just don't know where/how to begin tracking down this issue & I don't even know the tools to use. Maybe the router has tools that can help? But, if so, I don't know which they are or how to employ them.

Offhand, it seems like I might need some sort of hardware "thing" to "plug in" between the RJ45 cable plug and the RJ45 port at each "place" along the route to evaluate the signal & detect where it's first occurring? But I don't know what that would be called & it's just a guess, too.

So I'd appreciate any recommendations, suggestions, etc.

SETUP: Frontier FiOS 500/500 service:

- The FiOS fiberoptic cable is connected to the ONT (outdoors);

- 100' run of CAT 6 Ethernet cable between the ONT's Gigabit RJ45 port and the Gigabit RJ45 (WAN) port of my ASUS RT-AC87U router;

- a CAT 6 Ethernet cable is connected to each of 3 of the router's RJ45 LAN ports, with one running to each of 2 desktop computers & the 3rd running to a Gigabit switch providing Ethernet connections to media components (ROKU, Onkyo receiver, Oppo Blu-Ray player, SONOS system; etc.).

Thanks in advance!


Part of the Furniture
Your thought process is sound. As it's effecting two different PC's it seems unlikely that it's either of those or the cables connecting them to the router.

So the first place to look is in the router's System Log. Are there any messages there that coincide with the time the problem occurs.

The next place to look would be in to ONT's log, if it has one.


Part of the Furniture
You gave a good bit of information. But...which Asus router? What firmware version? What are you using for DNS?
My first guess would be an intermittent DNS failure. I get the same symptoms using Quad9 over DoT. Using Cloudflare Security, which the servers are 1/10 the distance of the Quad9 servers, I do not have the issue. I would recommend changing the router DNS servers first.


Part of the Furniture
RT-AC87U with v382.xx level firmware running in 2022? Time to get a new router. Don't hesitate, do it quickly (major security issues for Asus routers not running 386.xx level firmware from about the beginning of this year).

Current Order of Recommended Routers Late 2021


Very Senior Member
When you say freezes, the machine totally freezes, can't do anything, or you just have unresponsive internet for that time?

If it isn't totally frozen, try pinging the following during one of the freezes (from a problem machine):
The router LAN IP
The router WAN IP (should work but not sure on that older code base, so a failure is not necessarily an issue)
Your ISPs default gateway (the one asus is getting via DHCP on the WAN)
Your ISPs DNS server (again the one the asus is getting via DHCP)
if you still have time try an nslookup for the site you're trying to reach, or, or whatever
Based on the results that will help narrow down where the issue lies

If you have IPv6 enabled with your ISP, troubleshooting can get more difficult as it could be an issue related to just one protocol or the other. At the risk of getting jumped on by the v6 fans, try disabling it and see if the problem still exists. If nothing else it rules out one thing and helps make the above tests easier and more conclusive.

Another test you can try is connecting directly to the ONT (release your WAN P from the router first) from one of the problem machines and see if the issue persists. Just make sure that machine has a firewall enabled on it.

If the whole machine is locking up, I can't think of anything on the router that could possibly cause that, other than a spanning tree loop, but if you had one of those it wouldn't be intermittent typically, unless the routers STP is not fully functioning properly.

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