[Q] Wifi tethering: DNS (and probably UDP) - XPERIA X8 Q&A, Help & Troubleshooting

Workaround found. See below.
Being a newbie, I was not allowed to post to MiniCM thread, however I suppose it could be more relevant.
I have Sony Ericsson Xperia X8 with properly (with factory wipe etc) installed MiniCM7-2.2.1-shakira (Android 2.3.7) and 2.6.29.6-nAa-11 kernel. Overall very happy (especially comparing to 2.1 stock firmware from SONY), but...
Wifi tethering works perfectly, except... DNS.
Built-in server starts and listens on port 53. And resolves nothing (it simply causes timeouts). Using 8.8.8.8 or mobile operator's servers does not help: NAT seems to fail UDP passthrough. This also leads to DNS timeouts.
The other annoying (not fatal, but annoying) particularity is that hotspot switches off when on battery and when screen locks. Changing WiFi policy to always on does not help.
So thanks a lot to anybody who can help to solve this. Log harvested by logcat is attached.
No thirdparty software was used, only built-in Android features.

I don't now about the DNS issues but for WiFi hotspot bug there is no fix afaik, you'll have to bear with it. Perhaps connect phone to charger and set screen time out to some large value and then start tethering. Or perhaps try using USB tethering.
Sent from my E15i using Tapatalk 2

SpyderX said:
I don't now about the DNS issues but for WiFi hotspot bug there is no fix afaik, you'll have to bear with it. Perhaps connect phone to charger and set screen time out to some large value and then start tethering. Or perhaps try using USB tethering.
Sent from my E15i using Tapatalk 2
Click to expand...
Click to collapse
Thank you. In fact it is worth enough to connect to charger. It does not stop tethering with blank screen.
But DNS blows my mind... DNS server is user mode application, relatively simple... It looks like DNS server works behind the same NAT that throws out UDP.
I worked the problem by using a proxy server (proxoid or ProxUrDroid), but this solution sucks very much: is is too far from "push and use"...

Workaround found
DNS
The problem is in the way how built-in dnsmasq and NAT behave. NAT does not allow UDP traffic, and dnsmasq starts behind NAT. Then dnsmasq tries to contect upstream DNS servers using UDP and fails.
The solution is to prohibit dnsmasq from being DNS server and replace it with something more flexible.
Go to /system/bin with some root-enabled file manager.
Rename dnamasq to dnsmasq.real.
Create dnsmasq file with the same permissions and ownship as original dnsmasq (now dnsmasq.real) binary.
Edit it with text editor and write the following script to it:
Code:
#!/system/bin/sh
exec /system/bin/dnsmasq.real [email protected] --port=0
This dirty hack does nothing good itself except freeing port 53. Dnsmasq can has a config file with the same option passed in more elegant manner, but I found no way to make dnsmasq read it.
After throwing away dnsmasq's DNS, give a way to an awesome software piece — DNSLite (search Google Play, we are all very happy with XDA that does not allow outside links to me). It should run separately. And it has a killing feature: it can always contact upstream DNSs via TCP! So it saves the show.
BTW other way is to use proxies like ProxyDroid or ProxURDroid. I do not know when they get DNS info, but they also work. But this is definitely not so handy for clients attaching to the hotspot.
Power
Simply install Wake Lock - PowerManager from market, it works. Use the setting to turn screen and keyboard off, but leave CPU on: software access point relies on CPU being active.
Tethering while power is plugged is also a good idea: it does consume power. In this case nothing s needed to lock, the AP will keep on automatically.
Shutting down
Do not forget to shut down everything you started before (especially unlock power) to leave more charge in the battery.

Related

Running OpenVPN on the Kaiser (3G)

I've been struggling with OpenVPN on my Vario III on T-Mobile and hope someone can throw me a bit of a lifeline.
I can connect to my OpenVPN (running on my WRT54GS router) via wifi but the problem is when I try over 3G. Even when I've specified the provider and ticked "exclusive", it manages to connect to my OpenVPN server but I get no further connectivity (to webpages etc).
As said, via wifi this config on my Kaiser works perfectly...
Code:
remote xxxxxx.homeip.net
port 22
dev tap
secret "\\Program files\\OpenVPN\\config\\secret.key"
proto tcp-client
resolv-retry infinite
nobind
comp-lzo
cipher AES-256-CBC
route gateway 192.168.xxx.xxx
redirect-gateway
dhcp-option DNS 192.168.xxx.xxx
but when tried via 3G it seems to have a problem with setting the routing..
Code:
Mon Oct 22 21:58:00 2007 ROUTE: route addition failed using CreateIpForwardEntry: The parameter is incorrect.
Just wondering if there is something either with the T-Mobile network or the Vario III which is specifically stopping me from using OpenVPN
Or are my settings misconfigured?
I've also attached a full copy of the log.
Thanks for any help you can give (Give generously)
CP
Sounds suspiciously like a NAT traversal or proxy issue to me. On the HSDPA network, there's a proxy in the picture. I don't believe that's the case for the Edge network. That could easily be the cause of the problem.
Surely once the connection has been established the NAT issue shouldn't be a problem?
TBH I thought the route addition problem was due to the software being unable to update the local routing table?
NAT traversal issues often manifest themselves as connections that look like they're established, then die immediately. The VPN participants have to know the actual IP addresses of the devices involved, and understand that NAT is happening. Proxies also need to play a role in that process since they're effectively "standing in" for your device. And they may be configured not to permit IPSec traffic at all.
What you've described sounds exactly like NAT traversal issues - the negotiation appears to go just fine, but the actual connection dies on the vine. Since the end points don't have the right data from the negotiation (actual valid addresses to build the tunnel around), the route they try to build is invalid and fails.
In your log, it's impossible to tell since the IP addresses have been all translated to xxx.xxx.xxx.xxx. But I suspect that the ones up until the "TCP connection established with..." message are all displaying valid public IP addresses, and somewhere very shortly after that they start displaying private RFC 1918 addresses.
Proxies + NAT +IPSec = small nightmares. This is one of the reasons SSL VPNs have gained significantly in popularity.
Try Hamachi vpn
https://secure.logmein.com/products/hamachi/vpn.asp
Surur
PerfAlbion said:
In your log, it's impossible to tell since the IP addresses have been all translated to xxx.xxx.xxx.xxx. But I suspect that the ones up until the "TCP connection established with..." message are all displaying valid public IP addresses, and somewhere very shortly after that they start displaying private RFC 1918 addresses.
Click to expand...
Click to collapse
You have PM
Quick update:
I've just connected my Laptop to the internet via my Kaiser using 3G.
Ran OpenVPN and it connected without a problem.
Technically this would suggest that I should be able to connect with my kaiser but theres either a problem with my config or a bug in the PPC openvpn software :S
I haven't tried on UDP yet which will be my next test....
Any ideas?
Blimey, I didn't know there was a PPC client! I'll try it to see if it works with my setup.
Well I can't even get it to talk to my server so won't be able to help !
Fire up the card in your laptop and take a look at the IP address assigned to your machine. Since it's a different service, they may not be passing you through the proxy that's in place for the Kaiser. If you've received a public address, then you're on a "different network" even though both are 3G services.
PerfAlbion said:
Fire up the card in your laptop and take a look at the IP address assigned to your machine. Since it's a different service, they may not be passing you through the proxy that's in place for the Kaiser. If you've received a public address, then you're on a "different network" even though both are 3G services.
Click to expand...
Click to collapse
?? When you connect a laptop via BT to the kaiser, (using internet sharing) it creates a NAT which the traffic is passed over through the 3G service. Essentially using the same service..
Unless you mean the "service" between the windows software & the PPC/WM software is different?
Plus how'd you mean fire up the card in my laptop?
Cheers for your help on this btw.
I'm assuming that the Laptop data service and the PDA data service are treated differently within the AT&T network. While the PDA passes through a proxy, I suspect the laptop does not.
When I say "fire up the laptop card," I mean establish a connection and look at your IP address (ipconfig from a command prompt will show it). It may be a different IP address range than the PDA receives (which you could see using VxIPConfig or VxUtils). Even if it's within the same range, it may be bypassing the proxy.
So while you're using essentially the same technology, I suspect the services are implemented very differently, and that's what we're trying to sort out.
I dont believe it!!!
I downloaded VM Net Brower checked what IP addresses were being assigned and connected successfully! Loaded up www.whatismyip.org and it came up with the proxy of my PC at home.
Unfortunately, my phone was running incredibly slow and thought it best to do a soft reset... afterwards no matter what I do, I can't connect. I just cant figure out why or replicate what I did
Argh.. this is getting to me now... next on the agenda is to try changing the port number from 22 to 8080 or 80 and see what happens.

[Q] change ip address for WLAN tethering ?

Is it possible to change the ip-address range, so that a dhcp client receives an adress from a given subnet.
I looked for a dhcp server on the galaxy or dhcp settings but could not find it. There is only a dhcpcd.conf for the SGS as a WLAN client.
If someone knows, which config file I should look for, it would be great.
Background:
The SGS has a VPN connection and I want to share that connection with my notebook. Yes, I could establish another VPN connection from my notebook, but if that is not necessary it is nicer.
Thanks for any hints.
Gregor
Found another problem - the 192.168.34.xx can cause collisions within the company network if I run VPN.
Nobody with an idea ?
I'm still searching for a better way to it than recompiling everthing but at least this seems promissig https://code.google.com/p/android/issues/detail?id=11855
in my (very short) trys i wasn't able to configure a bridge for both interfaces so we may have to life at frist with 2 separat ip ranges but may can allow routing between the to interfaces. I assume that iptables is used to prevent this by default.

[Q] Wifi/network issues (not dhcp related)

Im having some issues with my new galaxy tab.
Whenever I try to use wifi/internet I get alot of network errors/timeouts/dropped packets, no matter what app I use.
whenever that happens I have to press refresh/retry a few times and suddenly it works, after a few minutes it starts giving errors again.
this is not the already known DHCP error, i can connect to the network fine and receive an IP without problems. the problem is the connection itself.
i have already tried to change my routers encryption from wpa tkip to wpa aes, which seems to reduce the number or errors I get but did not fix the issue completely. when I tried to use my htc ad-hoc hotspot with the tab it seemed to work better, could have been coincidence tho
some info:
- its a branded tab from tmobile austria
- the firmware is t-mobile branded PDA: P1000BOJJ3 Phone: p1000xxid CSC: p1000maxjj4
kernel: 2.6.32.9 root at SE-S611 1 build froyo.bojj3
- router is in my room, so the range is fine
so what can I do to fix this? anyone else having this problem? also, why does it say "root" in kernel I dont think I have root access?
ps: your spam check is running amok, cant even use at sign in my posts??
I get similar things sometimes, not sure about the solution. What are the errors you get onscreen?
The root bit means that Samsung build the kernel on a machine that was logged in as root, i.e.: they're stoopid
You get used to the spam filter
It's possible if your in a highly populated area that there is too much contention for air space. There is a great free app in the market called 'wifi analyser'. Use this to test if another wifi is overpowering yours. Also, use the time graph tick away in the background to check for dropouts.
The fix may be as simple as changing the channels of your access point.
Sent from my GT-P1000 using Tapatalk
Try enabling XPress™ Technology on your wireless router (if option to enable it exists and your routers supports it) analyze your network to see if there is interference from other networks. Finally adjust your router to 802.11 G/N setting I don't think you need a/b.
Hope it helps

'No Cast Devices Found' (Am I missing something?)

I'm really not seeing any threads with workarounds for this error message.
I know I haven't been around in quite a while, am I just missing them? If I am, please point me in the correct direction.
If not, I can update this thread with some workarounds I have found (May also help Google in helping their customers, can't explain any further than that). Seems like it would make sense to have a thread dedicated to that.
mattykinsx said:
I'm really not seeing any threads with workarounds for this error message.
I know I haven't been around in quite a while, am I just missing them? If I am, please point me in the correct direction.
If not, I can update this thread with some workarounds I have found (May also help Google in helping their customers, can't explain any further than that). Seems like it would make sense to have a thread dedicated to that.
Click to expand...
Click to collapse
These are a list of things that can be at play...Most are Router related
No Multicast capability, Multicast Disabled or Filtering On
2.4 Ghz band disabled or not supported by the router (CCast only has 2.4Ghz WiFi)
IGMP Enabled or Proxied
AP Isolation on
UPnP settings
IPv6 Disabled
MAC Filtering Enabled
Firewall and Security Programs blocking ports
Incompatible Routers
Check here for possible solutions
https://support.google.com/chromecast/table/3477832?hl=en&ref_topic=3447927
and make sure your CCast has a Solid White Light cause if not then you need to use the setup program to configure it
What if it works seemingly fine, but then proceeds to intermittently drop off and display the 'No cast devices found' error.
zcace said:
What if it works seemingly fine, but then proceeds to intermittently drop off and display the 'No cast devices found' error.
Click to expand...
Click to collapse
How is the WiFi signal at the Chromecast? The HDMI Extender can help a lot in some cases.
bhiga said:
How is the WiFi signal at the Chromecast? The HDMI Extender can help a lot in some cases.
Click to expand...
Click to collapse
WiFi is strong. It works fine from all my other devices, it's just Chrome. I'm on a Windows 8 PC. Sometimes it'll work perfectly for hours on end. I have everything except my LAN turned off (or so I think), checked binding orders, my windows firewall is off, and it just keeps happening.
Actually I will report back, I thought I had IGMP disabled. I didn't, so I just turned it off.
zcace said:
WiFi is strong. It works fine from all my other devices, it's just Chrome. I'm on a Windows 8 PC. Sometimes it'll work perfectly for hours on end. I have everything except my LAN turned off (or so I think), checked binding orders, my windows firewall is off, and it just keeps happening.
Actually I will report back, I thought I had IGMP disabled. I didn't, so I just turned it off.
Click to expand...
Click to collapse
If that doesn't change things, check if you can adjust your router's UPnP Advertisement time and see if that correlates with your dropoffs.
Beyond that you can try the Wireless Portable Devices setting in the Firewall and enabling IPv6 as described by folks in this thread.
I had similar issues when I first played with the Chromecast which were being caused by Wifi signal - it appears that due to the location of my Chromecast (in a media cabinet) the signal was severely degraded. I tried it in the TV directly (as opposed to the home theatre) and this increased the performance for me as it was out of the cabinet and ended up buying a hdmi extender to run it up into a higher location so it would get better signal.
Not sure if you're getting the same but that's what I'd look at.
zcace said:
What if it works seemingly fine, but then proceeds to intermittently drop off and display the 'No cast devices found' error.
Click to expand...
Click to collapse
http://forum.xda-developers.com/showthread.php?t=2443288
And the second thread is linked from that one.
Anyone who is using this in a Home Entertainment environment would be wise to get a Wireless AP extender to place near the Home Entertainment cabinet because all those devices throw off so much RF that can easily interfere with the CCast connection.
It's one of the reasons I wish they had a USB Cable similar to the one used for Flashcast that you could put a wired USB ETH dongle in and wire it up.
Thats something I would expect @Kyonz and Team Eureka to be adding to their ROM at some point. That would be a damn good upgrade to the Unit for those with Reception and Network issues. We might even get a sense of exactly what Bitrate the CCast Hardware can handle when the Network isn't getting in the way.
bhiga said:
If that doesn't change things, check if you can adjust your router's UPnP Advertisement time and see if that correlates with your dropoffs.
Beyond that you can try the Wireless Portable Devices setting in the Firewall and enabling IPv6 as described by folks in this thread.
Click to expand...
Click to collapse
This is getting weirder, IGMP disabled. It worked solidly for over a week, and now it's dropping off again. I can't help but think that wi-fi signal is strong as all my other devices work fine, and the CC is in the same room as the router, a month old Netgear R6200v2. I played with uPnP advertisement time and nothing changed, its still dropping off. Restarting the router fixes it. I feel like the problem is on the Windows side though, because every other device works perfectly fine, including Chrome on my Macbook, and all mobile devices.
zcace said:
This is getting weirder, IGMP disabled. It worked solidly for over a week, and now it's dropping off again. I can't help but think that wi-fi signal is strong as all my other devices work fine, and the CC is in the same room as the router, a month old Netgear R6200v2. I played with uPnP advertisement time and nothing changed, its still dropping off. Restarting the router fixes it. I feel like the problem is on the Windows side though, because every other device works perfectly fine, including Chrome on my Macbook, and all mobile devices.
Click to expand...
Click to collapse
Since rebooting the router seems to help it feels like it's some advertisement or multicast related thing. It "registers" at router start but eventually the client is ignoring it. Does the Windows machine go to sleep, turn off its network connection, or auto connect to VPN or another virtual network adapter?
Sent from a device with no keyboard. Please forgive typos, they may not be my own.
zcace said:
This is getting weirder, IGMP disabled. It worked solidly for over a week, and now it's dropping off again. I can't help but think that wi-fi signal is strong as all my other devices work fine, and the CC is in the same room as the router, a month old Netgear R6200v2. I played with uPnP advertisement time and nothing changed, its still dropping off. Restarting the router fixes it. I feel like the problem is on the Windows side though, because every other device works perfectly fine, including Chrome on my Macbook, and all mobile devices.
Click to expand...
Click to collapse
You mentioned Windows 8...
Make sure IPv6 is enabled on both the Computer and the Router.
If your router does not support IPv6 that may be the cause of your problem.
But it is on the list of Compatible routers which leads me to believe you have IPv6 disabled on the Windows8 machine.
bhiga said:
Since rebooting the router seems to help it feels like it's some advertisement or multicast related thing. It "registers" at router start but eventually the client is ignoring it. Does the Windows machine go to sleep, turn off its network connection, or auto connect to VPN or another virtual network adapter?
Sent from a device with no keyboard. Please forgive typos, they may not be my own.
Click to expand...
Click to collapse
Again let's keep in mind that the CC works perfectly fine from every other device. Been watching Breaking Bad on Netflix through my phone and it goes for hours and hours without a hitch.
With that said you're on to something with the sleep idea. My sleep for displays is set to 2 hours, and my hard drives is set to 3 hours, so I don't think that's it. All VPNs or extra LAN connections are off afaik. But turning off my network connection, that's a possibility. I found the 'Allow the computer to turn off this device to save power' option under Control Panel -> Network Connections -> Ethernet -> Properties -> Configure -> Power Management tab. Now, I tried this both allowing the computer to idle (dropped off) and while typing this very message (also dropped off). So it's not that particular setting. Also IPv6 is enabled in the Ethernet Properties. This is crazy, why doesn't this work out of the box!? Everything else did.
Google Chrome Canary is seemingly fixing a lot of people's issues.
https://www.google.com/intl/en/chrome/browser/canary.html
zcace said:
Again let's keep in mind that the CC works perfectly fine from every other device. Been watching Breaking Bad on Netflix through my phone and it goes for hours and hours without a hitch.
With that said you're on to something with the sleep idea. My sleep for displays is set to 2 hours, and my hard drives is set to 3 hours, so I don't think that's it. All VPNs or extra LAN connections are off afaik. But turning off my network connection, that's a possibility. I found the 'Allow the computer to turn off this device to save power' option under Control Panel -> Network Connections -> Ethernet -> Properties -> Configure -> Power Management tab. Now, I tried this both allowing the computer to idle (dropped off) and while typing this very message (also dropped off). So it's not that particular setting. Also IPv6 is enabled in the Ethernet Properties. This is crazy, why doesn't this work out of the box!? Everything else did.
Click to expand...
Click to collapse
Hmm, can't find it but I remember running across a mention of Chromecast discovery not working properly in some cases when there were multiple network interfaces installed (regardless of whether they're active). Windows also has some trouble with the network filter driver layer if there are two many filters installed (again, VPN adapters and firewalls).
Actually... maybe I'm overthinking things as I often do...
It's just that particular computer, right?
Can you try disabling all other Chrome extensions? I recall someone else ran into a conflict with another Chrome extension.
bhiga said:
Hmm, can't find it but I remember running across a mention of Chromecast discovery not working properly in some cases when there were multiple network interfaces installed (regardless of whether they're active). Windows also has some trouble with the network filter driver layer if there are two many filters installed (again, VPN adapters and firewalls).
Actually... maybe I'm overthinking things as I often do...
It's just that particular computer, right?
Can you try disabling all other Chrome extensions? I recall someone else ran into a conflict with another Chrome extension.
Click to expand...
Click to collapse
Indeed, only this computer has any issues. I tried turning off all chrome extensions, still no dice. I am sure there is one singular obscure setting somewhere we are missing. Or maybe its like 'mattykinsx' said, it's a Chrome issue?
zcace said:
Indeed, only this computer has any issues. I tried turning off all chrome extensions, still no dice. I am sure there is one singular obscure setting somewhere we are missing. Or maybe its like 'mattykinsx' said, it's a Chrome issue?
Click to expand...
Click to collapse
Quite possible it's a Chrome thing.
Perhaps create a System Restore point (or otherwise back up your current instance) and try the newfangled thing.
bhiga said:
Quite possible it's a Chrome thing.
Perhaps create a System Restore point (or otherwise back up your current instance) and try the newfangled thing.
Click to expand...
Click to collapse
I take it back. Downloaded Chrome Canary, installed only Google Cast, still drops connection after a couple of minutes.
zcace said:
I take it back. Downloaded Chrome Canary, installed only Google Cast, still drops connection after a couple of minutes.
Click to expand...
Click to collapse
Your Network location is set to Home or Work, yes?
Can you post a shot of the Advanced tab of your network interface's properties from Device Manager?
(Alt-PrtScn will capture the active window, or you can use the Snipping Tool)
bhiga said:
Your Network location is set to Home or Work, yes?
Can you post a shot of the Advanced tab of your network interface's properties from Device Manager?
(Alt-PrtScn will capture the active window, or you can use the Snipping Tool)
Click to expand...
Click to collapse
What are we trying to glean from this?

802.1x

Why Google you no like college students?
Hmmm this probably raises a good point, it's a bit hard to implement something like 802.1x though on a streamer device (where authentication is required per login of network prior to you having the ability to control the device).
I don't see this coming for awhile to be honest unless someone manages to hack it in - I just can't see Google releasing the ability to cache 802.1x network credential sets unfortunately due to the security implications.
Friend of mine had to buy his own router to plug in to the colleges ethernet ports in the dorm. Solved a variety of issues they were having.
Sent from my Nexus 5 using Tapatalk
fchowd0696 said:
Why Google you no like college students?
Click to expand...
Click to collapse
Beyond the lack of keyboard/interface, large networks in general fear multicast and UPnP because they have potential to easily clog the network.
Also remember that Chromecast in its current state has little security - it's designed for use within a trusted environment.
You probably don't want to be in the middle of Twilight with your girlfriend and suddenly your Chromecast switches over to SpongeBob SquarePants because someone else in the dorm decided BobsChromecast obviously wants to show SpongeBob...
Having your own router and local network will isolate your Chromecast to just your little piece of the campus network, though double-NAT might be an issue, and you should check with campus policy on use of personal WiFi router/AP hardware.
I've got a similar problem. I use a studentnet, were I can either plug in directly into the wall and log in once every day or setup a router with a PPTP-connection to automatically log into the student-network. I've got the latter set up and it works like a charm.
Thankfully I had a rootable CC so I could set it to use my ISP's DNS but I would love if it if I were able to use a different DNS (aka Unlocator/Unblock) to enjoy the US-version of Netflix, but every time I change the DNS-servers my internetconnection dies.
Is there any way to actually do fix my problem? I know this is more of a network-question than a CC-one, but CC is included in the problem
I use a Netgear WNR3500LV2 as my router.
Sent from my LG-D802 using Tapatalk
ninepoint said:
I've got a similar problem. I use a studentnet, were I can either plug in directly into the wall and log in once every day or setup a router with a PPTP-connection to automatically log into the student-network. I've got the latter set up and it works like a charm.
Thankfully I had a rootable CC so I could set it to use my ISP's DNS but I would love if it if I were able to use a different DNS (aka Unlocator/Unblock) to enjoy the US-version of Netflix, but every time I change the DNS-servers my internetconnection dies.
Is there any way to actually do fix my problem? I know this is more of a network-question than a CC-one, but CC is included in the problem
I use a Netgear WNR3500LV2 as my router.
Click to expand...
Click to collapse
First question is whether you can use a different DNS at all (or whether your ISP is blocking somehow).
Try doing a DNS lookup from another server on your phone/tablet via Ping & DNS or another app that lets you do that.
If that's successful, then it might work - go to the Eureka-ROM web panel at http://Chromecast_IP_addresss/ and turn off DHCP-supplied DNS, Apply, then select another DNS.
You will also need to force your phone/tablet to use the same DNS - otherwise your phone/tablet may be making requests from Mars, while Chromecast tries to retrieve stuff from Venus.

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