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Intermittent "destination address unreachable" when pining router
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NY
Aug 24, 2018, 5:42:48 AM8/24/18
to
What router fault could cause wireless devices (laptop, phone)
intermittently to lose contact with the router (can't even ping the gateway
address - destination address unreachable), even though the laptop believes
that it is still connected when you click on the wireless icon in the system
tray. The wireless icon says "no internet connection" but I don't think that
means that the router has lost its WAN connection, only that the laptop
cannot talk to the router.
It's a router at a holiday cottage where we're staying, so it's not possible
simply to reboot the router. The fault seems to clear itself after a few
minutes - I'm not sure whether anyone has to intervene or whether it rights
itself spontaneously.
There are no other wifi networks on the same or overlapping networks.
ipconfig reports a sensible IP address - ie not 169.x.x.x
intermittently to lose contact with the router (can't even ping the gateway
address - destination address unreachable), even though the laptop believes
that it is still connected when you click on the wireless icon in the system
tray. The wireless icon says "no internet connection" but I don't think that
means that the router has lost its WAN connection, only that the laptop
cannot talk to the router.
It's a router at a holiday cottage where we're staying, so it's not possible
simply to reboot the router. The fault seems to clear itself after a few
minutes - I'm not sure whether anyone has to intervene or whether it rights
itself spontaneously.
There are no other wifi networks on the same or overlapping networks.
ipconfig reports a sensible IP address - ie not 169.x.x.x
Andy Burns
Aug 24, 2018, 5:59:20 AM8/24/18
to
NY wrote:
> There are no other wifi networks on the same or overlapping networks.
> ipconfig reports a sensible IP address
You shouldn't need to, but if the router's outside your control it might
> There are no other wifi networks on the same or overlapping networks.
> ipconfig reports a sensible IP address
help to see what DHCP address it gets, then give that as a fixed IP
address ... do the same for DNS or use e.g 8.8.8.8 and 1.1.1.1
If you can fix your laptop to either 2.4GHz or 5GHz, try each, rather
than letting it choose and possibly flip-flop between them.
Graham J
Aug 24, 2018, 10:15:29 AM8/24/18
to
NY wrote:
> What router fault could cause wireless devices (laptop, phone)
> intermittently to lose contact with the router (can't even ping the
> gateway address - destination address unreachable), even though the
> laptop believes that it is still connected when you click on the
> wireless icon in the system tray. The wireless icon says "no internet
> connection" but I don't think that means that the router has lost its
> WAN connection, only that the laptop cannot talk to the router.
>
> It's a router at a holiday cottage where we're staying, so it's not
> possible simply to reboot the router.
I suspect you could turn all the power off at the meter, wait 10 secs,
> What router fault could cause wireless devices (laptop, phone)
> intermittently to lose contact with the router (can't even ping the
> gateway address - destination address unreachable), even though the
> laptop believes that it is still connected when you click on the
> wireless icon in the system tray. The wireless icon says "no internet
> connection" but I don't think that means that the router has lost its
> WAN connection, only that the laptop cannot talk to the router.
>
> It's a router at a holiday cottage where we're staying, so it's not
> possible simply to reboot the router.
and turn it all on. That ought to reboot the router unless it is
located in a different building, or has its own UPS.
> The fault seems to clear itself
> after a few minutes - I'm not sure whether anyone has to intervene or
> whether it rights itself spontaneously.
>
> There are no other wifi networks on the same or overlapping networks.
> ipconfig reports a sensible IP address - ie not 169.x.x.x
https://www.metageek.com/products/inssider/free/
(or an equivalent product)?
That would show whether the WIFi signal is disappearing intermittently,
and may indicate whether there are other sources of radio interference.
Once your laptop has acquired a sensible address it is likely to keep it
until you tell it to drop and re-establish the WiFi connection, because
as far as your laptop is concerned the wireless interface thinks it is
still connected. By contrast if you had a wired connection and
unplugged the cable, your laptop would lose its IP address and might get
a different one when you reconnect the cable.
--
Graham J
Woody
Aug 24, 2018, 2:36:55 PM8/24/18
to
"NY" <m...@privacy.net> wrote in message
news:0uednV7zBYKLTuLG...@brightview.co.uk...
connection as the device has been unable to contact the DHCP server.
--
Woody
harrogate3 at ntlworld dot com
Graham J
Aug 24, 2018, 6:12:39 PM8/24/18
to
an autoconfiguration address!!
So the conclusion is that when the laptop first connected to the wifi
signal it communicated with a DHCP server and was issued with a sensible
IP address. At some later time the laptop continued to think that there
was a wireless connection so it retained the IP address it was issued
with, but showed "no internet connection".
However in Windows 10 the icon can indicate "connection to the router
but not the internet" - see:
https://support.microsoft.com/en-gb/help/4000459/windows-10-wifi-icons
The OP confirms that he can't ping the router.
To the OP: what does does the WiFi icon show? If you have Windows 7
please refer to:
https://www.home-network-help.com/network-icon.html
Specifically item 4. The "staircase" component indicates the signal
strength (very crudely). Anything less than 2 bars generally means the
signal strength is not enough for a reliable connection; however the
icon has to show no bars at all for several seconds before the
connection drops. Clearly Windows 7 cannot distinguish between "no
connection to router" and "no internet connection", but the OP can, and
confirms that his intermittent situation is "no connection to router".
Try
ping <router-ip> -t
... and note the response times. If they are consistent at about 50mS,
but at other times fail completely - this suggests the wifi component is
working ok and the fault lies elsewhere. If the reply times vary then
the wifi channel is inadequate in some way. There may be other sources
of interference - a microwave oven, for example.
The OP mentioned that none of his WiFi devices connect when the
intermittent problem is present. It would be helpful to know whether
the fault occurs simultaneously across all these devices.
The OP is evidently on holiday, and probably has a smarphone. He
probably has been taking pictures. Very likely his phone tries to
upload new pictures to the cloud, and given the pictures may be many
megabytes and the holiday location has a very slow rural internet
connection, it is quite likely that the internet connection is saturated
with upstream traffic. This will cause downstream traffic to be
severely restricted (because the handshake traffic will have to share
the limited upstream bandwidth with the pictures being uploaded). Since
ping is a low-priority packet that may also be dropped if the router is
busy with other traffic. This is just speculation, but in the absence
of any useful diagnostics it may explain the situation.
--
Graham J
NY
Aug 26, 2018, 8:51:03 AM8/26/18
to
"Graham J" <gra...@invalid.com> wrote in message
news:plp3u0$dpr$1...@dont-email.me...
InSSIDer on laptop and on Android phone both show three SSIDs: two on the
same channel of 2.4 GHz and one on 5 GHz. The two usable SSIDs that accept
the WPA key that I've been given, both fail at the same time with the same
symptoms - if I'm connected to one and it drops out, the other will fal in
the same way.
I've tried setting a static IP, subnet and gateway to match those which the
router's DHCP hands out, and when the router has gone into funny mode, I
can't even ping the gateway with a static configuration.
It rights itself after a few minutes or an hour or so, though I'm not sure
whether any human intervention (eg power-cycling to reboot) is necessary.
When I first saw Windows say "no internet connection" I assumed that it was
the WAN that was dropping out (eg loss of ADSL sync or spontaneous logout
from ADSL) but when I found I couldn't even ping the router, I realised it
was a more fundamental problem. There may be other equipment (eg wifi
repeater, separate access point for holiday cottage to keep a guest network
separate from home use) so it may not be a simple router configuration.
news:plp3u0$dpr$1...@dont-email.me...
same channel of 2.4 GHz and one on 5 GHz. The two usable SSIDs that accept
the WPA key that I've been given, both fail at the same time with the same
symptoms - if I'm connected to one and it drops out, the other will fal in
the same way.
I've tried setting a static IP, subnet and gateway to match those which the
router's DHCP hands out, and when the router has gone into funny mode, I
can't even ping the gateway with a static configuration.
It rights itself after a few minutes or an hour or so, though I'm not sure
whether any human intervention (eg power-cycling to reboot) is necessary.
When I first saw Windows say "no internet connection" I assumed that it was
the WAN that was dropping out (eg loss of ADSL sync or spontaneous logout
from ADSL) but when I found I couldn't even ping the router, I realised it
was a more fundamental problem. There may be other equipment (eg wifi
repeater, separate access point for holiday cottage to keep a guest network
separate from home use) so it may not be a simple router configuration.
NY
Aug 26, 2018, 9:00:56 AM8/26/18
to
"Graham J" <gra...@invalid.com> wrote in message
news:plpvsm$2bn$1...@dont-email.me...
at the same time.
The staircase icon typically shows 4 or 5 bars. During a failure, this is
overlaid with a yellow exclamation mark. . Hovering over the icon gives the
message "Identifying <SSID> / No internet access" - case 4 in
https://www.home-network-help.com/network-icon.html. The signal strength at
times of exclamation mark does not drop to 1 or 2 bars, and the icon doesn't
change to no-bars-and-star (Case 2).
I've had it happen when wifi on the phone is turned off, so the phone won't
at those times being trying to sync photos etc.
I'm tending to use the wifi that the cottage supplies when it works, and the
internet on my mobile phone, with the laptop tethered to it, when the
cottage internet fails - turning on tethering and turning off wifi at the
latter times. I want to keep the usage of my mobile broadband to a minimum
as it's fairly limited and costly to buy another 250 MB of data.
If I happen to see the guy that runs the cottage, I'll ask whether his own
internet in the house goes off at the same time as the one in the cottage
(ie is it a router problem or a wireless extender problem). I think an
extender is involved since the SSIDs are EXT2-BTHomeSpot-72G and
EXT5-BTHomeSpot-72G (2 or 5 for 2.4 or 5 GHz).
I'm reluctant to reveal too much knowledge or he may try to rope me in to
investigate, which would make it a busman's holiday!
Graham J
Aug 26, 2018, 10:19:54 AM8/26/18
to
NY wrote:
[snip]
>
> InSSIDer on laptop and on Android phone both show three SSIDs: two on
> the same channel of 2.4 GHz and one on 5 GHz. The two usable SSIDs that
> accept the WPA key that I've been given, both fail at the same time with
> the same symptoms - if I'm connected to one and it drops out, the other
> will fal in the same way.
My point being that InSSIDer should show whether any or all of the
wireless signals disappears when you lose connection. Did you monitor
th signals while the connection is down?
> I've tried setting a static IP, subnet and gateway to match those which
> the router's DHCP hands out, and when the router has gone into funny
> mode, I can't even ping the gateway with a static configuration.
So as I suggested it has nothing to do with the WiFi connection but
indicates that the IP tranffic isn't reaching the router.
> It rights itself after a few minutes or an hour or so, though I'm not
> sure whether any human intervention (eg power-cycling to reboot) is
> necessary.
>
> When I first saw Windows say "no internet connection" I assumed that it
> was the WAN that was dropping out (eg loss of ADSL sync or spontaneous
> logout from ADSL) but when I found I couldn't even ping the router, I
> realised it was a more fundamental problem. There may be other equipment
> (eg wifi repeater, separate access point for holiday cottage to keep a
> guest network separate from home use) so it may not be a simple router
> configuration.
When you run ping does that indicate a sudden and total loss of replies
coincident with the connection failures, with otherwise reliable
replies? Or are the ping replies generally intermittent and just get worse?
--
Graham J
[snip]
>
> InSSIDer on laptop and on Android phone both show three SSIDs: two on
> the same channel of 2.4 GHz and one on 5 GHz. The two usable SSIDs that
> accept the WPA key that I've been given, both fail at the same time with
> the same symptoms - if I'm connected to one and it drops out, the other
> will fal in the same way.
wireless signals disappears when you lose connection. Did you monitor
th signals while the connection is down?
> I've tried setting a static IP, subnet and gateway to match those which
> the router's DHCP hands out, and when the router has gone into funny
> mode, I can't even ping the gateway with a static configuration.
indicates that the IP tranffic isn't reaching the router.
> It rights itself after a few minutes or an hour or so, though I'm not
> sure whether any human intervention (eg power-cycling to reboot) is
> necessary.
>
> When I first saw Windows say "no internet connection" I assumed that it
> was the WAN that was dropping out (eg loss of ADSL sync or spontaneous
> logout from ADSL) but when I found I couldn't even ping the router, I
> realised it was a more fundamental problem. There may be other equipment
> (eg wifi repeater, separate access point for holiday cottage to keep a
> guest network separate from home use) so it may not be a simple router
> configuration.
coincident with the connection failures, with otherwise reliable
replies? Or are the ping replies generally intermittent and just get worse?
--
Graham J
Graham J
Aug 26, 2018, 10:24:26 AM8/26/18
to
NY wrote:
[snip]
> If I happen to see the guy that runs the cottage, I'll ask whether his
> own internet in the house goes off at the same time as the one in the
> cottage (ie is it a router problem or a wireless extender problem). I
> think an extender is involved since the SSIDs are EXT2-BTHomeSpot-72G
> and EXT5-BTHomeSpot-72G (2 or 5 for 2.4 or 5 GHz).
So can you speculate - is the extender in the cottage, and the router in
another building? You could wander around the site with inSSIDer
running on your laptop - or more discreetly with a similar program
runing on your smartphone ...
> I'm reluctant to reveal too much knowledge or he may try to rope me in
> to investigate, which would make it a busman's holiday!
It may well be easier to solfe the problem than write about it in the
newsgroup!
And you may find that questioning the WiFi reliability may be on a par
with criticising somebody's driving - not taken well!!!
--
Graham J
[snip]
> If I happen to see the guy that runs the cottage, I'll ask whether his
> own internet in the house goes off at the same time as the one in the
> cottage (ie is it a router problem or a wireless extender problem). I
> think an extender is involved since the SSIDs are EXT2-BTHomeSpot-72G
> and EXT5-BTHomeSpot-72G (2 or 5 for 2.4 or 5 GHz).
another building? You could wander around the site with inSSIDer
running on your laptop - or more discreetly with a similar program
runing on your smartphone ...
> I'm reluctant to reveal too much knowledge or he may try to rope me in
> to investigate, which would make it a busman's holiday!
newsgroup!
And you may find that questioning the WiFi reliability may be on a par
with criticising somebody's driving - not taken well!!!
--
Graham J
NY
Aug 28, 2018, 5:39:37 AM8/28/18
to
"Graham J" <gra...@invalid.com> wrote in message
news:plud6p$koa$1...@dont-email.me...
temperamental here". I assumed it would be intermittent loss of ADSL
connection and/or intermittently very slow sync / data transfer. But it
looks as if it's IP traffic even to router that it intermittent.
When the connection comes back again I'll set a continuous ping running and
see if ping time gradually increases until it fails totally.
Discovered that router (gateway address) is not password-protected (!) - I
browsed to it expecting to see at least make and model (BT Business
Smarthub) and got to screens where I could modify config or restart it or
whatever. Good thing I'm honest. Netscan scan of IP addresses in the subnet
shows an extender (BT Dual Band) which *is* password protected. I hope
they've configured router's DHCP so as to exclude extender's own IP from the
scope...
Can't find extender in cottage so it may be in owner's house which is right
next door - and maybe they use it to extend wifi even within house and not
just to reach cottage.
NY
Aug 28, 2018, 6:19:47 AM8/28/18
to
"NY" <m...@privacy.net> wrote in message
news:T_OdnaAEGbXKhRjG...@brightview.co.uk...
> "Graham J" <gra...@invalid.com> wrote in message
> news:plud6p$koa$1...@dont-email.me...
>> NY wrote:
>>
>> [snip]
>>
>>> If I happen to see the guy that runs the cottage, I'll ask whether his
>>> own internet in the house goes off at the same time as the one in the
>>> cottage (ie is it a router problem or a wireless extender problem). I
>>> think an extender is involved since the SSIDs are EXT2-BTHomeSpot-72G
>>> and EXT5-BTHomeSpot-72G (2 or 5 for 2.4 or 5 GHz).
>>
>> So can you speculate - is the extender in the cottage, and the router in
>> another building? You could wander around the site with inSSIDer running
>> on your laptop - or more discreetly with a similar program runing on your
>> smartphone ...
>>
>>> I'm reluctant to reveal too much knowledge or he may try to rope me in
>>> to investigate, which would make it a busman's holiday!
>>
>> It may well be easier to solfe the problem than write about it in the
>> newsgroup!
>>
>> And you may find that questioning the WiFi reliability may be on a par
>> with criticising somebody's driving - not taken well!!!
>
> news:plud6p$koa$1...@dont-email.me...
>> NY wrote:
>>
>> [snip]
>>
>>> If I happen to see the guy that runs the cottage, I'll ask whether his
>>> own internet in the house goes off at the same time as the one in the
>>> cottage (ie is it a router problem or a wireless extender problem). I
>>> think an extender is involved since the SSIDs are EXT2-BTHomeSpot-72G
>>> and EXT5-BTHomeSpot-72G (2 or 5 for 2.4 or 5 GHz).
>>
>> So can you speculate - is the extender in the cottage, and the router in
>> another building? You could wander around the site with inSSIDer running
>> on your laptop - or more discreetly with a similar program runing on your
>> smartphone ...
>>
>>> I'm reluctant to reveal too much knowledge or he may try to rope me in
>>> to investigate, which would make it a busman's holiday!
>>
>> It may well be easier to solfe the problem than write about it in the
>> newsgroup!
>>
>> And you may find that questioning the WiFi reliability may be on a par
>> with criticising somebody's driving - not taken well!!!
>
> When the connection comes back again I'll set a continuous ping running
> and see if ping time gradually increases until it fails totally.
Further info now:
> and see if ping time gradually increases until it fails totally.
I ran a "ping 192.168.1.254 -t" to the router's gateway address. Out of 940
packets, times were: min 4 ms, max 56 ms, av 7 ms.- until I began to get "no
reply". That happened at same time as wifi icon got a yellow exclamation
mark and Teamserver connection to remote PC (back home) dropped out (*)
After this had happened, I checked with ipconfig, and IP was still sensible
values (ie IP in range 192.168.1.x). I connected to another network
(tethering to my mobile phone internet) and showed that IP details changed
to totally different subnet.
Then I connected to original network and IP details were back to 192.168.1.x
values. But couldn't ping router.
So... even when router cannot be pinged, its DHCP server can still hand out
valid IP addresses. So the router is not totally dead even at those times.
(*) My usenet server is configured to reject connections from any ISP other
than the one that runs it, so I have to log onto my PC at home to access
news. OK, I know I could go for an independent usenet provider like eternal
september...
Graham J
Aug 28, 2018, 6:50:30 AM8/28/18
to
NY wrote:
[snip]
>> When the connection comes back again I'll set a continuous ping
>> running and see if ping time gradually increases until it fails totally.
>
> Further info now:
>
> I ran a "ping 192.168.1.254 -t" to the router's gateway address. Out of
> 940 packets, times were: min 4 ms, max 56 ms, av 7 ms.- until I began to
> get "no reply". That happened at same time as wifi icon got a yellow
> exclamation mark and Teamserver connection to remote PC (back home)
> dropped out (*)
>
> After this had happened, I checked with ipconfig, and IP was still
> sensible values (ie IP in range 192.168.1.x). I connected to another
> network (tethering to my mobile phone internet) and showed that IP
> details changed to totally different subnet.
>
> Then I connected to original network and IP details were back to
> 192.168.1.x values. But couldn't ping router.
>
> So... even when router cannot be pinged, its DHCP server can still hand
> out valid IP addresses. So the router is not totally dead even at those
> times.
Er, no. Connecting to the original network is purely a WiFi function in
that your laptop has remembered the security key for that SSID and
establishes a Data Link (i.e. layer 2 in the OSI model, see:
<https://en.wikipedia.org/wiki/OSI_model>)
However your laptop's DHCP client can't actually contact the DHCP
server. I think it remembers the IP address it most recently used which
is associated with the MAC address of the remote end of the WiFi link.
I think you could test this. Having connected to a another network
(your mobile phone internet), then disconnected - at this stage reboot
your laptop - this should flush any ARP cache - and delete the WiFi
profile for the suspicious WiFi. Then try to connect to it. I expect
it to announce that it can see WiFi signals, to show the relevant SSID,
and ask for the security key. When you provide the key it will connect
to the remote WiFi node, but you will see the blue circle indicating
that it is trying to contact the DHCP server. It will fail, and at this
stage ipconfig should show an autoconfiguration IP address.
I can test this here later - I have an access point that I can
disconnect from the LAN.
Per your other post, you now know the IP address of the WiFi extender.
Normally you should be able to ping it. Then test whether you can ping
it while the fault is present. Check first that your laptop does indeed
have the correct IP address, if not set it statically for this test.
(Also, the DHCP server in the router should remember the IP address used
for the extender, even across a power cycle [it being a BT Business
Smarthub], so regardless of whether the extender got its IP from the
DHCP server or it was statically assigned in the device, there should
not be any clashes.)
This test should show more about the connection between the router and
the extender.
Which you could investigate: the router should show whether the extender
is connected by wire or wirelessly - the BT device probably has a pretty
diagram ...
--
Graham J
[snip]
>> When the connection comes back again I'll set a continuous ping
>> running and see if ping time gradually increases until it fails totally.
>
> Further info now:
>
> I ran a "ping 192.168.1.254 -t" to the router's gateway address. Out of
> 940 packets, times were: min 4 ms, max 56 ms, av 7 ms.- until I began to
> get "no reply". That happened at same time as wifi icon got a yellow
> exclamation mark and Teamserver connection to remote PC (back home)
> dropped out (*)
>
> After this had happened, I checked with ipconfig, and IP was still
> sensible values (ie IP in range 192.168.1.x). I connected to another
> network (tethering to my mobile phone internet) and showed that IP
> details changed to totally different subnet.
>
> Then I connected to original network and IP details were back to
> 192.168.1.x values. But couldn't ping router.
>
> So... even when router cannot be pinged, its DHCP server can still hand
> out valid IP addresses. So the router is not totally dead even at those
> times.
that your laptop has remembered the security key for that SSID and
establishes a Data Link (i.e. layer 2 in the OSI model, see:
<https://en.wikipedia.org/wiki/OSI_model>)
However your laptop's DHCP client can't actually contact the DHCP
server. I think it remembers the IP address it most recently used which
is associated with the MAC address of the remote end of the WiFi link.
I think you could test this. Having connected to a another network
(your mobile phone internet), then disconnected - at this stage reboot
your laptop - this should flush any ARP cache - and delete the WiFi
profile for the suspicious WiFi. Then try to connect to it. I expect
it to announce that it can see WiFi signals, to show the relevant SSID,
and ask for the security key. When you provide the key it will connect
to the remote WiFi node, but you will see the blue circle indicating
that it is trying to contact the DHCP server. It will fail, and at this
stage ipconfig should show an autoconfiguration IP address.
I can test this here later - I have an access point that I can
disconnect from the LAN.
Per your other post, you now know the IP address of the WiFi extender.
Normally you should be able to ping it. Then test whether you can ping
it while the fault is present. Check first that your laptop does indeed
have the correct IP address, if not set it statically for this test.
(Also, the DHCP server in the router should remember the IP address used
for the extender, even across a power cycle [it being a BT Business
Smarthub], so regardless of whether the extender got its IP from the
DHCP server or it was statically assigned in the device, there should
not be any clashes.)
This test should show more about the connection between the router and
the extender.
Which you could investigate: the router should show whether the extender
is connected by wire or wirelessly - the BT device probably has a pretty
diagram ...
--
Graham J
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