Say my Android device is on an IPv4-only network and I have a 6in4 tunnel (e.g. from HE/tunnelbroker.net) - how can I configure my device such that IPv6 traffic goes through that tunnel? Background: on a stock Linux system you can connect to the 6in4 tunnel via issuing 5 iproute2 commands or so.

I am testing IPv6 settings on my network and **during troubleshooting, I found that when using ULA address, ping to android device is failing. I am using Android 14. Is this expected behavior for Android or I might have some misconfiguration in my network?** I can still ping android device on IPv6 GUA (temporary + permanent RFC 7217) and ipv4. No issues there. In addition to that, Android device can reach local services on my network using ULA addresses

I observe the following problem with my Android phone (Sony Xperia XZ, Andoid Oreo 8.0.0) Though the phone seems to have a correct set of IPV6 addresses it fails to communicate when I use IPV6. the phone works OK using IPV4. Details -------------------------- I have about 5 Personal Computers in a LAN which can PING each other via their IPV6 adresses, and communicate via IPV4 and IPV6. I added my Android phone to the same LAN via WIFI/WLAN, at it can communicate via IPV4, but not IPV6. I have checked the IP setings of the phone, it gets a complete and correct set of IPV4 and IPV6 adresses from the local DHCP server. To start troubleshooting somewhere, I installed a PING tool on the phone, and found that it can PING any other computer via IPV4, but not via IPV6. On one of my PCs, I installed Wireshark to see what is happening, and this is what I found, if I PING the IPV6 address of the phone from the PC: On the pc, I initiate a PING test: ping [ipv6 address of phone] -6 -n 1 and this is what Wireshark revealed on ethernet level (with my comments): > mobile mac address discovery via multicast [pc mac] to [33:33:ff:4d:50]: Neighbor Solicitation for [mobiile IPV6] from [pc mac] [mobile mac] to [pc mac]: Neighbor Advertisement [mobile ipv6]: [mobile mac] > mobile phone mac address resolution success - try to ping [pc mac] to [mobile mac]: Echo (ping) request > response from phone: try to get PC mac address!" Has heard the PING request! [mobile mac] to [33:33:ff:f4:fd:12]: Neighbor Solicitation for [pc IPV6] from [mobile mac] > pc responds correctly [pc mac] to [mobile mac]: Neighbor Advertisement [pc ipv6]: [pc mac] > phone tries same again - has not "heard" the response !? [mobile mac] to [33:33:ff:f4:fd:12]: Neighbor Solicitation for [pc IPV6] from [mobile mac] > pc again responds correctly [pc mac] to [mobile mac]: Neighbor Advertisement [pc ipv6]: [pc mac] > 3rd retry! [mobile mac] to [33:33:ff:f4:fd:12]: Neighbor Solicitation for [pc IPV6] from [mobile mac] > pc patiently responds correctly once more [pc mac] to [mobile mac]: Neighbor Advertisement [pc ipv6]: [pc mac] This is where the PC gives up and shows a failed PIING error message. From what I see on the Wireshark trace, the phone fails to pick up the mac address resolution responses, and thus never knows about the Ethernet address of the PC, cannot send a response and and this is why the PING request fails. Trying the other direction, when I PING from the phone to the PC running Wireshark, not a single packet is captured, seems like the phone doesn't even try. To me ist seems like the IPV6 stack on the phone is dead, despite that DHCP has worked. Anyone who has deeper insight into the implementation details of IPv6 on Android who can give me any info how to resolve this? Thnx, Armin

I have a weird issue; for a single connect request to a server that has a single AAAA record my device runs two A queries instead and fails to connect. My setup is as follows: * LAN (a regular router) without IPv6 connectivity * Android 10 with only WiFi connectivity, having one fe80: and two fd14: addresses * Debian box, wired, running dnsmasq, acting as the DNS server for all devices * dnsmasq will reply that website foo.com has an IPv6 of the Debian box, and no IPv4 I can: * Connect from my phone to the Debian box using literal IPv6 address * Connect from other devices to foo.com * Connect to foo.com from JuiceSSH * Do ping6 foo.com successfully in Termux on the phone What I can't do, I can't connect from my phone to the Debian box via foo.com using regular apps such as Chrome, or my own app. JuiceSSH is the weird exception. I tried making a new app, adding INTERNET permission and this bit of code only:

thread {
    Socket("foo.com", 9000)
}

` This works consistently with the apps such as Chrome in that it doesn't connect and—from what I see in dsmasq logs—performs two A queries (both with NODATA-IPv4 response). It never performs an AAAA query. Inet*Address.getAllByName() behaves in a similar way. I tested with another device running Android 6, same outcome. What's going on here?

I am running Android One 9 on a Xiaomi Mi A3 and am trying to stop it from using IPv6 DNS servers, as they are essentially turning my RPI4 running Pi-Hole into a useless lump of silicon. How can I do this without having the phone ignore my instructions?? I have tried setting the WiFi connection to use a static IP and DNS info, as well as both the sudo sysctl -w net.ipv6.conf.wlan0.disable_ipv6=1 and the older echo 1 > /proc/sys/net/ipv6/conf/wlan0/disable_ipv6 commands but to no avail...the file retains the value 0 and my phone insists on using one IPv4 and one IPv6 DNS server no matter what I try! Please help me end this madness! MTIA :-)

I have a VPN (WireGuard right now, but the same behaviour manifested with OpenVPN) that provides me with an IPv6 address. I can confirm that it is working because pings (both from the android terminal with ping6 and to the android terminal from the other side of the VPN) work. This also confirms that the VPN is establishing the DNS server properly, as I am using an internal domain while pinging from Android. However, the browser (both Chrome and Firefox) only work properly when the main connectivity has also IPv6 enabled. That means that if I am connected to a WiFi that provides IPv6 connectivity, then the VPN works properly. But if I am using mobile data (my ISP doesn't provide IPv6) or I am using a IPv6-less WiFi, then the browser doesn't work for IPv6-only URLs. The android terminal ping6 command keeps working in all scenarios, meaning that the VPN is properly connected and working, but it's as if the browser/android machinery refuses to use AAAA records and the browser gives me an error. Is that a known issue? I am using Android 11. Can I change something or force Android to believe that there is an IPv6 connection established? Is the browser's fault? Is the DNS resolver fault? Edit: Forgot to mention: if I manually enter the IPv6 into the browser, it loads the web properly. So it seems that there is a DNS issue there, but the DNS is properly set up. So I assume that Android (or both browsers) are misjudging when to use AAAA records, hence the title of this question.

I have a Nextcloud running on a Raspberry Pi 4. My ISP: Vodafone (Germany) didn't give me a unique public IPv4 address, so I had to use my IPv6 instead to set an AAAA record for my domain (cloud.mydomain.de). Then my nextcloud was accessible from other computers via cloud.mydomain.de But I was not able to access it from my mobile phone, both from Wifi or mobile network. After some online digging, I found that the DNS settings might be the reason for that, and I installed and app that can change my DNS settings. And changed my DNS to cloudflare. After doing this I was able to connect from my phone to nexcloud using Wifi, but not when using mobile network. This is strange, because I checked and my mobile network has IPv6 enabled, also when checking with https://www.whatismyip.com/ I have an IPv6 address. Also, I checked using mobile network that I can connect to an IPv6 only website, like http://ipv6.google.com/ So, why can't I connect to my website using mobile networks? Anyone experienced something similar? Any idea what I can check next?

Android long ago implemented support for the privacy extensions of IPv6 networking. It was in 4.0 (Ice Cream Sandwich). The RFC for the privacy extensions doesn't specify (or even recommend) a TTL for temporary addresses, but typically they have a lifetime of 24 hours. My question is how is the expiry time chosen? Is it at multiples of 24 hours after the last boot? Or it is tied to the local timezone (and happens overnight)? Or is it at random, with some jitter from a 24-hour schedule? Or something else?

Using a current version of JuiceSSH on Android, I'm trying to set up a New Connection to my system at fe80::f9cd::4687::90cd::5da2. I've confirmed that I can ssh to that address from a Windows machine. But when I try to save the connection in JuiceSSH it tells me "Invalid Address". (I tried single colons too, no improvement. I haven't tried _no_ colons yet.) In case it matters, I'm using an Identity which has the same Private Key that I used from Windows, pasted into JuiceSSH as multiple lines between -----BEGIN OPENSSH PRIVATE KEY----- and -----END OPENSSH PRIVATE KEY----- lines, which seemed to be what JuiceSSH wanted to see (?). It's an ed25519 key, which JuiceSSH claims it supports; I'm not sure whether that's supposed to be indicated explicitly somewhere. But I wouldn't expect wrong key to cause an "Invalid Address" message. I presume I'm missing something obvious. Any ideas on what would be welcome. (BTW, I'm perfectly willing to try other Android SSH clients, but Juice seemed to be the most commonly recommended.)

I'm trying to capture connections using tproxy, but I'm unable to receive IPv6 TCP connections. IPV4 TCP and both UDP work properly. TCP v4 and v6 are both received from the same accept call. I'm on Android 9. PORT=2080 MARK=2080 iptables -t $TABLE -A $CHAIN -p tcp -j TPROXY --on-port $PORT --tproxy-mark $MARK iptables -t $TABLE -A $CHAIN -p udp -j TPROXY --on-port $PORT --tproxy-mark $MARK ip rule add fwmark $MARK lookup 100 ip route add local default dev lo table 100 ip6tables -t $TABLE -A $CHAIN -j LOG --log-prefix='[iptables] ' ip6tables -t $TABLE -A $CHAIN -p tcp -j TPROXY --on-port $PORT --tproxy-mark $MARK ip6tables -t $TABLE -A $CHAIN -p udp -j TPROXY --on-port $PORT --tproxy-mark $MARK ip -6 rule add fwmark $MARK lookup 100 ip -6 route add local default dev lo table 100 The log output shows ICMP packets and TCP packets with IPv6 and IPv4 addresses, but only IPv4 gets accepted on the listener. Occasionally something connects from WSL on my laptop, but nothing else connects over ipv6 and browser tests such as https://ipv6-test.com/ say ipv6 failed. Running the command curl google.com in WSL hangs until I press ctrl+c, at which point the accept call returns the now useless socket.

As far as ipv4 DNS is concerned, Android (at least version 9) can override default DNS settings fairly well. Firstly, it is possible to set net.dns* to the desired value. Secondly,

-t nat

works, and lets the user redirect the packets to port 53 anywhere required. With ipv6 however, things are not that easy. Android 9 (at least mine) does not support

-t nat

. Moreover, Android sets some internal DNS-related setting when obtaining the DNS address from SLAAC/RDNSS, which is not reflected in

, and insists on using it, regardless of what is in net.dns*. The only tool I am aware of, that might be somehow useful, is

-t mangle

, but it still seems quite limited. How can I override (or at least view) the default DNS address obtained from RDNSS?

Android 10. Trying to disable ipv6 (yes, I know the second line below appears redundant). echo 1 > /proc/sys/net/ipv6/conf/all/disable_ipv6 echo 1 > /proc/sys/net/ipv6/conf/wlan0/disable_ipv6 The values stay as long as I have wifi turned off: # cat /proc/sys/net/ipv6/conf/wlan0/disable_ipv6 1 But as soon as I turn wifi on, something changes (only) the wlan0 value back to 0: # cat /proc/sys/net/ipv6/conf/wlan0/disable_ipv6 0 If I change it back to 1 again, it gets changed back to 0 within a few seconds (and in Settings / About phone, I can actually see the ipv6 addresses return). Does anyone know what causes this (and how I can prevent it)?

I have Pixel 3a without SIM card, so I use this phone only with WIFI. How can I disable IPV6 in this phone? That the phone will use only IPv4?

My Pixel 6 can't connect to a few domains like api.reddit.com, api.bitwarden.com, WSJ images, etc. I'm using [PingTool](https://play.google.com/store/apps/details?id=ua.com.streamsoft.pingtools&hl=en_US&gl=US) to run ping and tracert to certain domains. |Phone|Domain|Network|DNS|Result| |--|--|--|--|--| |Pixel 3|api.reddit.com: DNS -> IPv4|home wifi|203.0.113.2, 203.0.113.3|✅| |Pixel 3|api.reddit.com: 151.101.57.140, IPv4 direct|home wifi|203.0.113.2, 203.0.113.3|✅| |Pixel 3|api.reddit.com: 2a04:4e42::200::396, IPv6 direct|home wifi|203.0.113.2, 203.0.113.3|❌| |Pixel 6|api.reddit.com: DNS -> IPv6|T-mobile|203.0.113.1, 203.0.113.2|✅| |Pixel 6|api.reddit.com: 151.101.57.140, IPv4 direct|T-mobile|203.0.113.1, 203.0.113.2|✅| |Pixel 6|api.reddit.com: 2a04:4e42::200::396, IPv6 direct|T-mobile|203.0.113.1, 203.0.113.2|✅| |Pixel 6|api.reddit.com: DNS -> IPv4, before IPv6 kicks in 30 seconds later|home wifi|203.0.113.1, 203.0.113.2|✅| |Pixel 6|api.reddit.com: DNS -> IPv6|home wifi|203.0.113.1, 203.0.113.2|❌| |Pixel 6|api.reddit.com: 151.101.57.140, IPv4 direct|home wifi|203.0.113.1, 203.0.113.2|✅| |Pixel 6|api.reddit.com: 2a04:4e42::200::396, IPv6 direct|home wifi|203.0.113.1, 203.0.113.2|✅| |Pixel 6|api.reddit.com: DNS -> IPv4|gym wifi|?|✅| |Pixel 6|api.reddit.com: 151.101.57.140, IPv4 direct|gym wifi|?|✅| There's something going on with IPv6 DNS and it affects a number of sites: Reddit, WSJ, Fitbit, etc. How do I disable IPv6 for wifi? Most of the instructions I've found only apply to mobile networks.

I have two Android phones. Same hardware model, one with android 10 and the other with 11. Both phones connect to the same telco. On both phones I can browse to test-ipv6.com and get a 10/10 indicating IPV6 on each handset is working. I then enable mobile hotspot and test from my laptop. Via the android 10 phone the laptop receives a V6 IP and the above website reports a 10/10 from the laptop Via the android 11 phone, the laptop does not get a V6 IP, and the above website report 0/10. I have looked though as many settings on Android 11 handset as I can, and scoured the internet for ideas but I cannot determine why a V6 IP is not allocated from the 11 handset. Ideas?

I wonder if Android has support for IPv6? I have heard that the phone company I use has support for IPv6 and I have a IPv6 address if I visit http://ipv6.whatismyipv6.net.ipv4.sixxs.org/ . But I can not visit IPv6-only sites like http://ipv6.google.com , why is that? Does Android have support for IPv6?

I have access to the IPv6 internet through Charter Communication's 6rd implementation. A number of CDNs fail to work correctly over IPv6, which causes a number of sites, including facebook, to have significant issues (pictures don't load, pages don't load, etc.) On my desktop, I can disable IPv6, and these issues go away. Is it possible to do that on a stock android phone / tablet? (not rooted) _Edit:_ From the comments, I've learned that the actual issue is a MTU issue. So I'd be equally interested in a method to set a lower MTU on android as well.

I'm using several Android devices that have Android 6.0.x and 6.0.1, and that I want to use in an IPv6 island ("private") network. The Android devices are either attached to a WiFi-to-Ethernet bridge, or some tablets even accept USB 2.0 Ethernet dongles using OTG cables. The IPv6 network has RAs signalling the IPv6 prefix to use, as well as DNS IPv6 server address, and optionally some more-specific IPv6 routes. There are neither DHCPv6 nor DHCPv4 servers available. Well, there are DHCPv6 servers in this network, but they only respond with delegated prefixes. Unfortunately, I cannot reliably connect my Android devices to this network. For cross-checking, an ordinary Linux Raspbian-equipped Pi does immediately become connected and works correctly, using DNS and getting proper addresses. Even when I set a static IPv4 address, my Android devices often don't correctly connect in that they don't use IPv6 DNS, albeit it is getting advertised (RFC 5006). I have to set fake IPv4 DNS server addresses to be able to set the static IPv4 parameters. But even then, the Android devices aren't properly working, either not correctly using DNS or even getting disconnected after some seconds. What kind of IPv4 connectivity do Android devices expect?

my landline only has an IPv6 address (well in addition IPv4 via crappy DSLite). I'm anyway trying to set up an owncloud server at home and access it from remote locations. So the task by now is to access the owncloud server via IPv6 using my Android 5.0.0 phone (Moto G 2014). If I open the IPv6 address in my browser on the phone while connected to the same WiFi as the owncloud server everything works fine. But once I turn off WiFi and switch to cellular data the server can't be accessed anymore even though my router is configured to pass every connection to the owncloud servers IPv6 address range. This result is still reasonable since via the mobile network I only have an IPv4 address and no IPv6 address, so I can't communicate directly with an IPv6 target. Are there some tricks to still reach an IPv6 host through an IPv4 connection on Android? Using tunnels ect? Or is this completely impossible by design? Thanks a lot for replys!

I have a Nexus 5X (running stock firmware) which [supports Bluetooth 4.2](https://support.google.com/nexus/answer/6102470?hl=en) . How do I use [6LoWPAN](https://en.wikipedia.org/wiki/6LoWPAN) to share the internet from my phone with BLE devices? Is it as simple as enabling Bluetooth tethering in settings?