Very strange problem with wireless

fitshase

Mr_Oink wrote: »

Don't mean to be pedantic, but you've not mentioned any other devices - you just mention:


You don't say you have other machines that are working faultlessly whilst your laptop grinds to a halt. You don't mention how any other machines are connected to the network.

From original post:-

"I can also use the internet on other devices (a different laptop, kindle and phone) and log onto the router using the other laptop so I know it's not the router or the ISP."

Mr_Oink wrote: »

You mention static IP's. Are they all configured to use the same name servers?

They are given static IP from the router.

Mr_Oink wrote: »

If it were me, my train of thought would go: When this outage happens, can I traceroute through to known good servers like google - if not where does it die? Can I get random name queries to work with something like nslookup ? Can I telnet the IP address of web servers and get a pulse?

How would I go about doing this (I've no experience of "traceroute" "nslookup" or "telnet")?

BackOnTrack

Well as DNS is configured at the device level you could have different dns configured for each machine.

The apps that seem to continue working would have persistent connections and therefore once the connection is established do not need to do further DNS lookups, I think. Thats why I suggested a dns issue.

fitshase

BackOnTrack wrote: »

Well as DNS is configured at the device level you could have different dns configured for each machine.

The apps that seem to continue working would have persistent connections and therefore once the connection is established do not need to do further DNS lookups, I think. Thats why I suggested a dns issue.

Cheers. How would I go about resolving the DNS issue on the specific machine?

BackOnTrack

Well I would start with opening the command prompt and type "ipconfig /flushdns". See if the problem goes away. As usual with intermittent problems it can be a pain to see if they are fixed. You could also try using openDNS (google it) and set that as a default or secondary dns.

fitshase

BackOnTrack wrote: »

Well I would start with opening the command prompt and type "ipconfig /flushdns". See if the problem goes away. As usual with intermittent problems it can be a pain to see if they are fixed. You could also try using openDNS (google it) and set that as a default or secondary dns.

OK, done the "ipconfig /flushdns" and will see if that resolves it.

Mr_Oink

fitshase wrote: »

From original post:-
"I can also use the internet on other devices (a different laptop, kindle and phone) and log onto the router using the other laptop so I know it's not the router or the ISP."

Good, assuming they are not looking at cached content.

fitshase wrote: »

They are given static IP from the router.

Are you sure these are static addresses from the router? IE have you set up address reservation so the same machines get the same static IP's each time, or do you mean the router just gives them a dynamic IP? Personally I don't think this is relevant to your issue - but you may want to be clear in your own head.

fitshase wrote: »

How would I go about doing this (I've no experience of "traceroute" "nslookup" or "telnet")?

This may be really sarcastic, but you could try this: http://lmgtfy.com/?q=using+tracert

But I'm not going to be that horrible. Personally I am not familiar with W7 and I have no desire to own it - so this has been run on an XP box - I'm sure you can adjust it for W7.

Open up a command prompt (start > run and type "cmd" and press enter). On Windows the command 'traceroute' is called 'tracert'. Just enter:

tracert -d 8.8.8.8

(if you leave off the -d option it will run slower as it tries to resolve names for each IP hop).

Naturally yours will be different, but should look something like this:

http://bayimg.com/AAeOLAADe

I'd practice this with it all working so you know what is normal. That way *if* it dies, you'll have a good idea where.

As for NSLOOKUP - again, in a command prompt just type:
nslookup example.com

The key here is NOT to use a domain you have recently been - so to avoid using something in the local cache. example.com is good and even mashing a few keys and getting a NX domain error will tell you the process works - again practice it so you know what is normal.

Finally telnet. Now on Vista I vaguely recall it was an extra you had to install, so this may be true also on W7. As a tool it really it is only useful in this context for telling you if you can connect to something on a given port. The Windows telnet client is a little quirky but....

telnet 74.125.230.112 80

(just one of googles IP addresses)
Should result in the terminal going blank waiting for HTTP input - if you have connected. That would be GOOD. If it *can't* connect, it will try to connect then blow you out saying 'connect failed':

C:\Documents and Settings\user1>telnet 74.125.230.112 80
Connecting To 74.125.230.112...Could not open connection to the host, on port 80
: Connect failed

Again, a couple of practice runs with it all normal will help you spot what is not normal and which bit is 'broken'. if not, somebody here should be able to with some knowledge of what works and what does not work.

It may be worth checking your MTU size (not set to over 1500) and that you've not disabled ICMP somewhere in the security settings. Lots of twonks say you should turn this off, but it kills a rather useful and important path MTU discovery feature (PMTUD) which can help where the MTU size changes across a network.

In passing, I had much misery with NTL (or as it is now 'Virgin') and random inexplicable drop outs. All of which turned out to be issues with THEIR use of caching proxies to 'speed up' your browsing. I'm not sure if they still use them - but they would always blame *your* kit and never take responsibility for the issue.

Hopefully some nugget of use for you in there the next time it occurs.

fitshase

Mr_Oink wrote: »

Good, assuming they are not looking at cached content.

Nope - tried some random sites on different machines - besides, I don't think the Kindle has a cache(?)

Mr_Oink wrote: »

Are you sure these are static addresses from the router? IE have you set up address reservation so the same machines get the same static IP's each time....

Static addresses from router so they always have the same IP address.

Mr_Oink wrote: »

Open up a command prompt (start > run and type "cmd" and press enter). On Windows the command 'traceroute' is called 'tracert'. Just enter:

tracert -d 8.8.8.8

(if you leave off the -d option it will run slower as it tries to resolve names for each IP hop).

Naturally yours will be different, but should look something like this:

http://bayimg.com/AAeOLAADe

It looks exactly like that at the moment.

As for Telnet and NSLookup I'll test it now and then again if/when the problem occurs again.

Mr_Oink wrote: »

It may be worth checking your MTU size (not set to over 1500) and that you've not disabled ICMP somewhere in the security settings.

Checked the MTU size on the router and it is set at 1500. Will reduce if the problem occurs again and see if that makes a difference.


I should have also added that I could ping the router and get a response when the problem happened (I don't know if that makes a difference).

fitshase

OK, it has happened again this morning so tried all of the advice:-

Microsoft Windows [Version 6.1.7600]
Copyright (c) 2009 Microsoft Corporation. All rights reserved.

C:\Users\User>tracert -d 8.8.8.8

Tracing route to 8.8.8.8 over a maximum of 30 hops

1 <1 ms <1 ms <1 ms 192.168.0.1
2 7 ms 5 ms 5 ms 10.3.72.1
3 7 ms 7 ms 7 ms 80.1.170.33
4 8 ms 9 ms 8 ms 195.182.175.229
5 9 ms 8 ms 9 ms 213.105.174.234
6 16 ms 15 ms 16 ms 212.43.162.86
7 23 ms 22 ms 21 ms 212.43.163.70
8 19 ms 23 ms 19 ms 212.250.14.162
9 30 ms 20 ms 36 ms 209.85.255.175
10 28 ms 27 ms 27 ms 66.249.95.173
11 29 ms 25 ms 26 ms 209.85.251.231
12 25 ms 32 ms 35 ms 209.85.243.85
13 27 ms 27 ms 30 ms 8.8.8.8

Trace complete.

C:\Users\User>telnet 74.125.230.112 80
'telnet' is not recognized as an internal or external command,
operable program or batch file.

C:\Users\User>ipconfig /flushdns

Windows IP Configuration

Successfully flushed the DNS Resolver Cache.

C:\Users\User>nslookup volvocars.co.uk
Server: UnKnown
Address: 192.168.0.1

Non-authoritative answer:
Name: volvocars.co.uk
Address: 193.183.236.252


C:\Users\User>nslookup example.com
Server: UnKnown
Address: 192.168.0.1

Non-authoritative answer:
Name: example.com
Addresses: 2620:0:2d0:200::10
192.0.32.10


C:\Users\User>nslookup ofasihoi.com
Server: UnKnown
Address: 192.168.0.1

*** UnKnown can't find ofasihoi.com: Non-existent domain

C:\Users\User>


I can access the USB Hard Drive attached to my router but I cannot access other machines. I can ping other machines and get a response but cannot access them.

I couldn't try the telnet option as it needs to be installed and I don't have it.

This is getting rather frustrating!

BackOnTrack

Trying changing your DNS, as outlined at http://www.mediacollege.com/computer/network/dns.html, to the google public dns

• 8.8.8.8
• 8.8.4.4

fitshase

BackOnTrack wrote: »

Trying changing your DNS, as outlined at http://www.mediacollege.com/computer/network/dns.html, to the google public dns

• 8.8.8.8
• 8.8.4.4

Just changed that on my laptop but was wondering if that would affect local traffic (given that I cannot get on to my local machines when the problem happens).