Destination host unreachable issue

[cerberuss]

I'm having a nightmare trying to resolve this issue so I thought I'd put it up here to see if anyone can shed a little light on the situation.

Here it goes..

etc

same exact problem. consulted some people already, checked net for answers and even had a specialist here for 6 hours, checking for timeouts and "destination host unre...". still no clue of what to do.
replaced modem, router, had my laptop's Wi-fi re-checked, reinstalled all drivers, done everything apart from a wipe.
i have no idea what else to do.

if there is anyone who had this problem and solved it please let me know.

p.s.: forgot to add - 3 laptops are conected to the router via wi-fi. all 3 have the same problem. isp swears nothing is wrong with their system.

[InspectorGadget]

You didn't say anything about your provider or the history of your problem. I doubt everything is EXACTLY the same as the original poster.

Are all other Internet services working except for Ping? Does your ISP assure you that they allow Ping through? Have you tried connecting one machine to wired Ethernet directly from the modem, and doing it that way?

Please provide more information.

- The Inspector

[cerberuss]

to the inspector: sory for not posting details.
the history of the problem goes way back, possibly more than 6 years, ever since i got a wireless usb module for my PC. there were sudden disconects from the network, no real pattern to that. after some angry calls to the ISP i went to the nearest computer store and bought a new router, since that was the advice i got from my ISP. the connection was working fine for approx 3-4 days. after it was back to the usual DC's every 1h, 20min, 5min... after 3 USB wireless sticks and a few weeks the connection was somewhat stable. i still kept getting disconected but much less frequently (1, 2 times a day, sometimes even a few days without dropping)

then i bought a toshiba sattelite laptop with a built in wireless switch. it was like dejavu. started lagging, disconecting, couldnt find wireless networks nearby. it was hell.
so, the router was brand new, at the time also the modem was new but still the connection was playing tricks. no surprise when the connection stabilised after a month maybe after i bought the laptop. still disconects sometimes.

almost a month ago i bought 2 more laptops for the office. the day i bought them and plugged em in my 5 month old router (best money could buy at the time) "died" and had to be replaced with a new one (even more expensive than the last one). connection worked fine on all 3 laptops, digital satelite sistem (updating via net) and 1 pc for about 8 hours. after that everything started lagging and after pinging the well known line appeared. "destination host unreachable".

so...

any idea what could be wrong? im out of ideas. a proffessional is coming to check my network again tomorow. dunno what he will accomplish since he was here 3 days ago, pondering and trying all he could think of for more than 6 hours...


ahh, internet service does not work when dest.host is unreachable. sometimes it doesnt drop the connection, only as if it put it on hold or something.
just checked with my isp and yes, they allow ping through.
tried to connect all machines directly to the modem and all work.

if there's any more data i could forward you, please let me know.

[InspectorGadget]

Thanks for all that info. I feel a lot better oriented now.

Well, the key phrase is, "Internet service does not work when dest. host is unreachable." I assume this means you can't connect to web sites and can't download mail or FTP, as well as being unable to Ping.

If your ISP says everything is working fine, they are probably lying.

What ISP is it? What kind of data connection (cable, fiber, DSL, satellite, wireless)?

Does Ping ever work (i.e., does it work when the other network services are working)?

One other thing... Do you have any kind of traffic indicator on the router or on an ethernet switch connected to it? I had some local network anomalies once and only clued into it when the "collision" light on my Netgear switch started going crazy and the utilization light was flickering to signify maxing out my 100Mbps bus (when only two computers were online at once).

So there's still a chance that there's some kind of hiccup at your end. One way you can rule this out is to ping your router's LAN port when things are going wacky, or ping another machine on your LAN, and see if they're responding OK when the Internet services are not working. Let me know about this test if you can.

- The Inspector

[cerberuss]

isp is SiOL (main provider in my country), its a vDSL line, laptops are on wireless and pc wired to the router.

here's a ping situation when pinging router.

*timing out without actually dropping the connection. all downloads just stopped for the time of the time out and resumed right after.

and another situation

*this happens 10-15 times in a row within 1 hour.


about the traffic indicator. dunno what that would be be but i checked the router's menu and found a tag with that refference. ill check it out later.

[InspectorGadget]

OK, that's really interesting. Something is interfering with your internet stream on an intermittent and varying basis. It could be in the ISP connection, in your router/LAN, or in the wireless link.

So have you tried connecting a computer directly to the router with wired Ethernet? This would be the first step in diagnosing your overall problem: to rule out any contribution by the wireless link itself. I work at a company making wireless audio equipment, and we've found all kinds of interference in the 2.4GHz band that can screw up a WiFi signal.

Let me know if you have done or if you can do this test, and we'll go on from there.

- The Inspector

[cerberuss]

ok so i was up almost all night monitoring ping while torrenting. from around 8pm GTM+1 to around 2am there were almost no timeouts, after that there were a few time outs (3-5 of "timeout" lines when pinging). at 5am or so "destination host unreachable started" and at 7am the connection dropped completely. note that untill this DC the line did not disconect, was just lagging or so it seemed. i tried to play an online rpg to check if i would be lagging. and yes, loads of lag, almost disconects, all in all a horrible online experience. about the laptop being connected via ethernet to the router : did it. works fine but i cant have a wire where i am now. id have to drill holes and play the handy man and i just cant see myself in that role.
good news: today a technician is coming with a load of controlled equipment. i hope we get to the bottom of this.

so you realy think this anomaly is caused by an interference with the 2,4ghz band? what kind of devices would cause the disruption.

i have a samsung smartphone with BT and wifi. i keep BT off most of the time so i dont think that would be it. wifi i keep it always active. think this could be the issue? i seriously doubt it since i had this phone for like less than a year. no microwave ovens nearby.


p.s. maybe im just immagining stuff but i noticed that the connection often times out when the ventilator in my laptop stops. could it be related?

[InspectorGadget]

No, I actually think it's the ISP's fault. I'm just trying to give you as much "ammunition" as possible to argue with them to convince them that the problem is not on your end.

Things that can interfere with WiFi are things like old (analog) 2.4GHz cordless phones, old (analog) wireless headphones, baby monitors, A/V wireless links, wireless video cameras, wireless game controllers, WiMAX stations, sometimes even fluorescent lights or bad electrical connections/motor circuits. Near my home there is some kind of broken paging transmitter at a nearby auto dealer that spews RFI all across the band and made my analog 2.4GHz headphones and telephones useless, and the digital ones barely work (limited range). It limits my WiFi range and performance to about half normal.

The pattern of your link degradation is most suggestive of a network-bottleneck issue in your ISP's network or backbone connection. Pacing or throttling of certain subnets or connections is very difficult and most ISPs do it poorly, so if their geographic or topological subnet organization is such that they have high-bandwidth-link users next to lower-bandwidth-link users, the lower-bandwidth users can be swamped by the high-bandwidth ones when they crank it up all the way.

But the ISP won't want to look at that because it'll take some real work.

One bluetooth device won't affect things. If 10 or 20 people in the nearby vicinity all started using Bluetooth at once, it could cause interference.

If it's an wireless camera, baby monitor, or phone system, or a high-bandwidth WiFi user, you might be able to change your WiFi channel and avoid it. Have you ever tried changing your WiFi channel? Most access points default to channel 6 in the middle of the band. Try moving to a low-numbered or high-numbered channel and see if it improves things at a time when you're having degraded or "disconnected" condition.

So let me know if your technician can rule out the WiFi link by connecting to the router during the problem condition on the WiFi-connected PC. Maybe they can also help you try to change the channel (if you haven't already been down this road).

- The Inspector

[cerberuss]

hahahhaha
just as you said. switched the channel and look what i got all day!


it was that simple i guess. i will monitor for another few days. might be its not over yet:)

anyway thnx loads

and the work you do here is priceless. thank you.

[johnwill]

Even though it appears you're having the same problem, please start a new thread when you have a new issue. It's very difficult to keep two problems straight and who's working on what in a single thread.

I've created a new thread for your issue here.

Note: You will need to post complete details of your configuration and your specific issue in this new thread for us to help you.

Thanks for your cooperation.