NY
2024-07-29 11:06:04 UTC
The Problem
===========
Some of you who have frequented this newsgroup for a year or so may
remember that I posted a question and request for diagnostic help in
working out why one particular web site (webspace that I rent from
GoDaddy) suddenly started giving intermittent problems when browsed from
Android and iPad devices.
The symptom was that one (but never all) of my Android devices, and also
my wife's iPad, using a variety of different browsers, would fail to
browse to the web site. One day it would be one device that was
affected, another day it would be a different device. Some browsers gave
a "cannot access" message, whereas others would eventually display a
page after a delay of about 90 seconds. Rebooting a device and/or my
router would usually solve the problem - for a few weeks. It was not
router-specific: it happened with both Plusnet's own router and my
TPlink router.
Wireshark traces (*) showed the client sending TCP packets at 1, 2, 4,
... second intervals with no response from the server. Eventually, a
response would arrive and the HTTP dialogue then proceeded, and the page
was displayed. Intriguingly it only seemed to happen with my VDSL
connection, and not with my mobile phone's Vodafone internet connection.
Sometimes turning the phone's/tablet's wifi off and then back on
(clearing a cache?) seemed to work for a while: typically I could then
browse a few different pages on the GoDaddy webspace and then it would
fail again.
I did see it very occasionally with Linux PCs (Ubuntu, Mint, MX) running
Firefox. The common factor seemed to be Linux, because Android and iPad
OSes are based on Linux. Windows PCs worked fine.
GoDaddy weren't much help in helping me diagnose the problem.
"Solution"
==========
Last month GoDaddy notified me that they were migrating my webspace from
one of their servers to another one. And ever since then, we have had no
problems. So it looks as if something at their old server had gone bad
and the migration to the new servers had caused the problem to go away.
(*) Getting Wireshark traces was not easy because of the router's
"switch" which tries to filter out all traffic that is not to/from a
device that in on that Ethernet segment. A PC that was connected by
Ethernet would not see all traffic on wifi, as expected because of the
switch. More strangely, even if the Wireshark PC was connected to the
same wifi network as the phone that experienced the problem, it didn't
see all traffic. I had to buy a managed switch which had the option of
mirroring traffic on one Ethernet port to another port, and connect a
wifi access point to one port and the Wireshark PC to the mirror, and
then connect the phone that was experiencing the problem to that wifi.
===========
Some of you who have frequented this newsgroup for a year or so may
remember that I posted a question and request for diagnostic help in
working out why one particular web site (webspace that I rent from
GoDaddy) suddenly started giving intermittent problems when browsed from
Android and iPad devices.
The symptom was that one (but never all) of my Android devices, and also
my wife's iPad, using a variety of different browsers, would fail to
browse to the web site. One day it would be one device that was
affected, another day it would be a different device. Some browsers gave
a "cannot access" message, whereas others would eventually display a
page after a delay of about 90 seconds. Rebooting a device and/or my
router would usually solve the problem - for a few weeks. It was not
router-specific: it happened with both Plusnet's own router and my
TPlink router.
Wireshark traces (*) showed the client sending TCP packets at 1, 2, 4,
... second intervals with no response from the server. Eventually, a
response would arrive and the HTTP dialogue then proceeded, and the page
was displayed. Intriguingly it only seemed to happen with my VDSL
connection, and not with my mobile phone's Vodafone internet connection.
Sometimes turning the phone's/tablet's wifi off and then back on
(clearing a cache?) seemed to work for a while: typically I could then
browse a few different pages on the GoDaddy webspace and then it would
fail again.
I did see it very occasionally with Linux PCs (Ubuntu, Mint, MX) running
Firefox. The common factor seemed to be Linux, because Android and iPad
OSes are based on Linux. Windows PCs worked fine.
GoDaddy weren't much help in helping me diagnose the problem.
"Solution"
==========
Last month GoDaddy notified me that they were migrating my webspace from
one of their servers to another one. And ever since then, we have had no
problems. So it looks as if something at their old server had gone bad
and the migration to the new servers had caused the problem to go away.
(*) Getting Wireshark traces was not easy because of the router's
"switch" which tries to filter out all traffic that is not to/from a
device that in on that Ethernet segment. A PC that was connected by
Ethernet would not see all traffic on wifi, as expected because of the
switch. More strangely, even if the Wireshark PC was connected to the
same wifi network as the phone that experienced the problem, it didn't
see all traffic. I had to buy a managed switch which had the option of
mirroring traffic on one Ethernet port to another port, and connect a
wifi access point to one port and the Wireshark PC to the mirror, and
then connect the phone that was experiencing the problem to that wifi.