PLEASE FOCUS ON 2ND UPDATE AS THIS RESOLVES THE ISSUE AS A WORKAROUNDI see that this problem goes way back. I just got hit with it on my Samsung Galaxy S II. The problem seems to be a corrupted DHCP cache. The problem is, that cache can't be cleared unless the phone is rooted. So using a different router may work, but also, I'll bet, even the old router will work, if you changes it's DHCP IP assignments. Ex. let's say your routers assigns: 192.168.20.xx. If you have change it to say, 192.168.25.xx, I bet it will work. I'm going to try that tomorrow. In my case, the S2 will NOT connect to ANY of my 3 routers. All routers use the same IP segment. Yet, the S2 connects just find to my tethered Samsung Galaxy Note 2, which has a different segment. If changing the segment works, I'll post back here.
But this has been reported for a very long time. One must ask, WHY has Samsung not gotten a fix out for it. They could have a new version of Android that auto clears the DHCP cache or at least has a manual option to clear it. (I like the auto clear thing as best option).
UPDATE 1 Ok, I couldn't wait. Here's how my system works. I have 3 routers. The primary router, which is my ADSL router, is the one that assigns IPs via DHCP. I have another router, an N router in the livingroom. It was not assigning IPs. But I enabled it on this 2nd router, but gave it a range of 250 to 255 only.
The S2 now connects to the router. (discovered that there's no internet access. See Update 2 for resolution)
So this proves the issue on these devices is a nasty bug in the Android software. The fix would be so simple. Just add code to auto clean out and/or an option to force a clean of DHCP caching (data).
**********************************************************************
UPDATE 2 A WORKAROUND IS FOUND THE S2 CONNECTED TO THE ROUTERS, BUT NO INTERENT ACCESS!
So for those interested in how I did finally gain internet access, here's some info. I only post this in hopes that it may help others get around the problem. BUT, now that I know what's going on with the Android versions below 4.1, I suspect this will only work for a while, until the device's DHCP data (stack?) becomes corrupted again. And until I ROOT the phone, I don't see any other way to clear out the DHCP cache.
I have 3 routers:
- Router 1 (main N router hard wire connected to internet)
- is the Gateway and it's IP is xxx.xxx.xx.2
- it handles DHCP requests
- DHCP set to range xx = 10 to 90 (using 192.168.15.xx)
- most devices in house connect via wire and using static IPs below and above the .xx range.
- some others using DHCP
All devices working perfectly and stable.
- Router 2 (our outdoor on the patio router - PLEASE NOTE, AN OUTSIDE ROUTER IS VERY IMPORTANT IN THE SUMMER. AS IS AN OUTDOOR BEER FRIDGE
)
- uses Static IP xxx.xxx.xx.100 to communicate with Router 1
- DHCP disabled
- Router 3 (in our living room, used to connect 3D TV, PS3, computer controlled PVR and other equipemtn, via wire)
- uses Static IP xxx.xxx.xx.150 to communicate with Router 1
- DHCP disabled
THIS IS THE ONE TO WATCH.
So, last night, when I got it to "connect", what I had done was to Enable DHCP on Router 3 and set its range, 240-255.
The S2 did pick up an IP adddress, xxx.xxx.xx.253
This should have worked, but I suspect that because the DHCP was coming from Router 3, it may not have pushed the correct Gateway IP. So it won't see the interent.
I then Disabled DHCP on Router 3.
I went into Router 1, the Gateway, and changed the DHCP range from 10-90 to 240-253.
I rebooted the S2 and right away, it connected to the router, picked up an IP and now is on the internet.
So I really do not believe anyone NEEDS to buy a new router. Just change the DHCP range.
What makes me realize this, is when people said that they bought a new router, it worked.
Different routers have different IP segments.
i.e. a D-Link may have 192.168.1.xxx or 192.168.15.xxx
a Linksys may have 192.168.50.xxx and so on.
So that different address, for some reason, the Android devices will now connect. I suspect that what's happening inside the Android devices with this problem, when using the same IP range, there's corruption and its trying to read what's there and getting confused.
When changing part of the range, and not sure if going from a 2 digit 4th octect to a 3 digit 4th octet is enough to change the bit , it just works.
So the person who wrote the app, WiFi Connection Fixer "Root" got it right. It's nothing more than clearing out the DHCP cache (I wonder if clearing DNS cache may also help).
BUT, the only problem there, is thanks to Samsung, or makers of the Android version for the S2, that's locked out to Super Admin level (which is really stupid if you think about it. This should be at a level where people can clean them out when necessary... and clearly, there's a lot of people with this issue).
I sure hope this helps anyone with this problem, even though this thread is very old. Which also begs the question, WHY has Samsung (and others??) not provided a firmware update that fixes this easy to fix problem???
But this has been reported for a very long time. One must ask, WHY has Samsung not gotten a fix out for it. They could have a new version of Android that auto clears the DHCP cache or at least has a manual option to clear it. (I like the auto clear thing as best option).
UPDATE 1 Ok, I couldn't wait. Here's how my system works. I have 3 routers. The primary router, which is my ADSL router, is the one that assigns IPs via DHCP. I have another router, an N router in the livingroom. It was not assigning IPs. But I enabled it on this 2nd router, but gave it a range of 250 to 255 only.
The S2 now connects to the router. (discovered that there's no internet access. See Update 2 for resolution)
So this proves the issue on these devices is a nasty bug in the Android software. The fix would be so simple. Just add code to auto clean out and/or an option to force a clean of DHCP caching (data).
**********************************************************************
UPDATE 2 A WORKAROUND IS FOUND THE S2 CONNECTED TO THE ROUTERS, BUT NO INTERENT ACCESS!
So for those interested in how I did finally gain internet access, here's some info. I only post this in hopes that it may help others get around the problem. BUT, now that I know what's going on with the Android versions below 4.1, I suspect this will only work for a while, until the device's DHCP data (stack?) becomes corrupted again. And until I ROOT the phone, I don't see any other way to clear out the DHCP cache.
I have 3 routers:
- Router 1 (main N router hard wire connected to internet)
- is the Gateway and it's IP is xxx.xxx.xx.2
- it handles DHCP requests
- DHCP set to range xx = 10 to 90 (using 192.168.15.xx)
- most devices in house connect via wire and using static IPs below and above the .xx range.
- some others using DHCP
All devices working perfectly and stable.
- Router 2 (our outdoor on the patio router - PLEASE NOTE, AN OUTSIDE ROUTER IS VERY IMPORTANT IN THE SUMMER. AS IS AN OUTDOOR BEER FRIDGE
)- uses Static IP xxx.xxx.xx.100 to communicate with Router 1
- DHCP disabled
- Router 3 (in our living room, used to connect 3D TV, PS3, computer controlled PVR and other equipemtn, via wire)
- uses Static IP xxx.xxx.xx.150 to communicate with Router 1
- DHCP disabled
THIS IS THE ONE TO WATCH.
So, last night, when I got it to "connect", what I had done was to Enable DHCP on Router 3 and set its range, 240-255.
The S2 did pick up an IP adddress, xxx.xxx.xx.253
This should have worked, but I suspect that because the DHCP was coming from Router 3, it may not have pushed the correct Gateway IP. So it won't see the interent.
I then Disabled DHCP on Router 3.
I went into Router 1, the Gateway, and changed the DHCP range from 10-90 to 240-253.
I rebooted the S2 and right away, it connected to the router, picked up an IP and now is on the internet.
So I really do not believe anyone NEEDS to buy a new router. Just change the DHCP range.
What makes me realize this, is when people said that they bought a new router, it worked.
Different routers have different IP segments.
i.e. a D-Link may have 192.168.1.xxx or 192.168.15.xxx
a Linksys may have 192.168.50.xxx and so on.
So that different address, for some reason, the Android devices will now connect. I suspect that what's happening inside the Android devices with this problem, when using the same IP range, there's corruption and its trying to read what's there and getting confused.
When changing part of the range, and not sure if going from a 2 digit 4th octect to a 3 digit 4th octet is enough to change the bit , it just works.
So the person who wrote the app, WiFi Connection Fixer "Root" got it right. It's nothing more than clearing out the DHCP cache (I wonder if clearing DNS cache may also help).
BUT, the only problem there, is thanks to Samsung, or makers of the Android version for the S2, that's locked out to Super Admin level (which is really stupid if you think about it. This should be at a level where people can clean them out when necessary... and clearly, there's a lot of people with this issue).
I sure hope this helps anyone with this problem, even though this thread is very old. Which also begs the question, WHY has Samsung (and others??) not provided a firmware update that fixes this easy to fix problem???
Last edited:
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