More computer panic

[Chris Hogg]

Over the last couple of days I've been having trouble with my connections to various web sites that I use. I have a x64 PC running Win 10, a Dynamode wireless USB adapter and a BTHub6.

Yesterday, and more so today, connecting to internet web sites has been impossible, for example Forte Agent won't connect, nor will Thunderbird for mail, nor Firefox for general web browsing, even though my Realtec USB wireless LAN utility tells me I have a good internet connection, the light on the Hub is blue (indicating internet connection) and the network and the windows internet settings utility tells me I have a secure connection to the internet. Firefox just tells me it can't connect to whatever website I try.

Yesterday, the computer eventually made the appropriate connections, bit by bit (some started to work quite soon, but Agent and Thunderbird mail took a while before they would connect. I don't use TB for usenet), so I thought it might just be that the internet was very busy, but today nothing would connect. Eventually I tried a system restore back to two days ago, but it failed (said I'd probably got an AV running, and to switch that off and try again). But it all seems OK now, although if system restore didn't actually run, I'm not convinced it isn't going to happen again.

I have a laptop that will run off the same hub, and that worked OK, so not the hub or the internet connection itself.

The fact that yesterday it came back bit by bit made me think it was hardware that was gradually failing, but now I'm far from sure. Can anyone suggest what is happening, and more to the point, how to correct it?

Oh bugger as I expected it's gone off again. Switched it all off and went away to get lunch, now it's back on again and I can try posting this.

Is it overheating somewhere? I may try opening up the case and giving the insides a thorough de-dust.

[John Rumm]

The first thing is to identify where in the big stack of things that need to work, something isn't. Having another machine that is working ok, at a stroke eliminates the router and the broadband (and assuming that is connected via wifi as well) the wifi.

So that suggests a problem at the PC end. Lots of things can stop internet comms working correctly - even something simple like a computer with too much error in it time of day or timezone can stop secure https connection completing.

Problems with name resolution can make site appear to be unreachable as well.

You can run some tests if you drop into a command prompt (click the start button and type CMD - the first match it finds will probably be "Command Prompt". If you right click on that and "Run with administrator access), you will get a command line where you can try some things.

So for example, if you type:

ping

You should see some message bounce off a google web server. If you get an error that it can't find the site, it might indication that what you have is a name resolution problem.

type

ipconfig /all

That will show all the basic details for all the network interfaces it can find. Post what it says about your main wifi link an we might be able to give some more pointers.

It is probably more likely to be software...

[Paul]

PS> nslookup

Server: UnKnown \___ My home router does not have a name. Address: 192.168.2.1 / That number is the "gateway address".

Non-authoritative answer: Name: e120265.dscx.akamaiedge.net Addresses: 2600:140a:5000:9::17df:1134 \ 2600:140a:5000:9::17df:1119 \___ Look for IPV4 and IPV6 addresses. 104.124.10.91 / Connecting via the wrong one, can 104.124.10.27 / be slower (due to search order). Aliases:

Browser:

IP Address: xxx.xxx.xxx.156 IPv4 <=== says I used IPV4 to get there.

If we check what that web site offered, it has both.

PS> nslookup

Non-authoritative answer: Name:

Addresses: 2606:4700:130:436c:6f75:6466:6c61:7265 <=== IPV6 172.64.80.1 <=== IPV4 (a 172.x in the public range)

An ISP can provide two DNS servers. On Windows, a dumbass algorithm is used, where the DNS servers are always consulted in order. If the first DNS server is down, Windows makes you wait for the timeout, before it consults the second DNS. In Linux, the working DNS is consulted first, and only if the working one does not respond, does Linux consider swapping the order and trying the other one first.

In Windows, you can change the DNS, by taking the configuration off Auto and using the dialog box to type in addresses. There are several providers of DNS servers (Cloudflare, Google, ...) you can use in a pinch, if your ISP DNS setup is defective. You should select these carefully, as there can be dodgy offerings.

8.8.8.8 1.1.1.1

The ISP DNS addresses are served to you via things like DHCP, and instead of using a load balancer, some ISPs use a fleet of separate DNS addresses and you can sometimes be served equipment that is in the process of rebooting. That's what my previous ISP used to do. I did a lot of manual entry of DNS addresses, while using that ISP. The DNS the current ISP provides, is five nines material, and the details are hidden behind just two addresses for the entire setup. You never have to play with it, to get it working.

You can try a traceroute to a popular node, to see what route the comms are taking.

PS> tracert

Tracing route to e120265.dscx.akamaiedge.net [104.124.10.91] over a maximum of 30 hops:

1 1 ms <1 ms <1 ms 192.168.2.1 <=== my router 2 13 ms 13 ms 12 ms \ 3 20 ms 13 ms 13 ms \___ My ISP forwarding 4 13 ms 16 ms 13 ms / 5 14 ms 13 ms 13 ms <=== Some Canadian Level3 style address 6 204 ms 108 ms 13 ms ae3.torix-yto.netarch.akamai.com [23.203.148.193] 7 13 ms 13 ms 12 ms a104-124-10-91.deploy.static.akamaitechnologies.com [104.124.10.91]

Trace complete.

Where torix would be Toronto Exchange. And that is a damn short tracert. If I traced to my news server, it could be 12-15 hops. The news server for this message, will be in Finland.

Paul

[Brian Gaff]

Mangled nameserver cached on the machine in question perhaps. That list has to be correct as it one supposes converts the web page friendly names to the e numeric IP addresses. Brian

[Chris Hogg]

Thanks for the suggestions. Sod's law of course, but the problem seems to have 'gone away', at least for the moment. Fingers crossed.

But if it returns, I shall move the computer nearer to the hub and connect it directly with an Ethernet cable. That at least will tell me if the wireless USB adapter is at fault.

[Bob Eager]

It strikes me that another reason might be an IP clash. Some glitch has caused two network members to get the same IP address, and they are swapping between them.