IPv6 only networks not working -- looks like a DNS issue (alpha 3) #9143
Comments
|
Yep that's to be expected as there isn't any support yet for DNS servers via an IPv6 address. Not sure how many people will run an IPv6-only network right now, but it is for sure something that needs to be fixed at some point in time. |
P-R-O-C-H-Y
added
Type: Feature request
|
It doesn't look too hard. There is a bit of parsing code in dnsIP() that only has IPv4 (affects display; shouldn't affect function), but the main issue looks to be that both IPv6 DNS mechanisms (stateless DHCPv6 and RDNSS) are configured as off. Most of the function, if you configure them on, seems to be automatic (DHCPv6 also needs to be enabled in code). First I was trying to add IPv6 DNS via DHCPv6 to arduino-esp32 and I am getting a linker (ld?) error "undefined reference to `dhcp6_enable_stateless'". I presume this means although the header is there, because the options at precompile time was missing CONFIG_LWIP_IPV6_DHCP6, then the functions are just not included in the compiled code (they are guarded). How do I get a custom version of esp32-arduino-libs? The repository at espressif/esp32-arduino-libs says it has pre-compiled versions, and has headers but no source. Do I need to download https://github.com/espressif/esp-idf and then build that myself (with the needed config changes)? I will also have a look at adding via RDNSS. |
Telcos are starting to switch to IPv6 only for their consumer mobile networks, e.g. Telstra here in Australia (who I work for): https://www.sidn.nl/en/news-and-blogs/australias-telstra-switches-mobile-users-to-ipv6-only Some ISPs have started to provide IPv6 only connections, e.g. T-Mobile in USA and several ISPs in India. While global IPv6 traffic is about 45% it varies by country, with India being ~70%. Corporations might deploy new networks as IPv6 only, or configure guest networks for reduced configuration and increase security (less vectors for attack with single stack). Both AWS and Azure will now be charging for (public) IPv4 address, while IPv6 will remain free, which will be another motivation. Technologies such as Thread are now available, based on 6LowPAN, which, by definition, is IPv6 only. There is also some versions of ESP32 chips, e.g. the ESP32H2, that support Thread, which would (by definition) be an IPv6-only network. |
|
I've been running dual-stack IPv6 at home since 2010, as I'm also convinced for the need to have IPv6. I doubt providers would dare to completely drop IPv4 support right now as there are just too many sites out there without IPv6 addresses. Therefore I don't expect IPv6-only to become really common in the next few years. |
|
@sgryphon this is how you build custom libs: https://github.com/espressif/esp32-arduino-lib-builder |
|
Hello, can you please validate this against 3.0.0-RC1 version? Thanks |
VojtechBartoska
added
Status: Test needed
|
Check all the merged PRs and it is looking great! Tested with M5Stack Core 2, using the following PlatformIO configuration and the test app from https://github.com/sgryphon/iot-demo-build/tree/main/m5stack/m5unified_wifi_https Configuration with current Libs idf-release/v5.1 and Arduino-ESP32 3.0.0-rc1 (these are the merged branches in Espressif). Not: For PlatformIO, also need to use my platform patch as PIO doesn't support 3.0.0 yet. Results across different network types and destinations, including IPv6-only networks to IPv4-only destinations via NAT64, and all working with TLS (HTTPS):
Not tested, but without NAT64, then an IPv6-only network can't connect to IPv4, but a dual-stack network would just use IPv4:
IPv6 enabled examplesAll of these examples use the same code and the same IP configuration, only differing in which network they are connected to. The same code runs across all network types. Logs for TLS (HTTPS) from dual-stack network to dual-stack destination: IPv6-only network to an IPv4-only destination. Note the DNS lookup returns the DNS64 address, while the destination server (in the response) sees the IPv4 NAT address. On an IPv4-only network (Shadow), connections fall back to IPv4 only. Note that IPv6 is still enabled, so you get a link-local address, it just isn't useful for public (DNS) addresses, so is ignored. Note that the IPv4 address is a private network address, but the destination (in the response) sees the same IPv4 NAT address as above, i.e. both are NAT, just NAT44 instead of NAT64. Because IPv6 is still enabled, it means if this device is moved to a dual-stack network (as above), it will continue to work. IPv6 disabled exampleYou get similar results if IPv6 is simply not enabled, i.e. don't call If your code can't yet handle IPv6 (e.g. it breaks pushing them into a too-short string buffer), then simply don't turn it on. Note: Normally you should leave IPv6 enabled, and the device will adjust depending on the network abilities. Only disable IPv6 if your code breaks because of it. |
|
Issue can be closed. It is good to have IPv6 working! |
Board
m5stack-core2
Device Description
M5Stack Core2 ESP32 IoT Development Kit for AWS IoT Kit, https://shop.m5stack.com/products/m5stack-core2-esp32-iot-development-kit-for-aws-iot-edukit?variant=37687799251116
Hardware Configuration
Just the M5Stack Core2
Version
latest master (checkout manually)
IDE Name
PlatformIO
Operating System
Ubuntu 22.04
Flash frequency
240Mhz
PSRAM enabled
yes
Upload speed
115200
Description
I have been testing out the alpha 3 master with the initial IPv6 code now merged in.
I have got it working on my M5Stack Core2 device for dual-stack, but on my IPv6-only network it can't make HTTP connections and is reporting a DNS issue. It does not list my IPv6 DNS server.
With IPv6 there are two available DNS mechanisms, RDNSS where DNS servers are part of Router Advertisement (RA) options, and DHCPv6 stateless, where RA is used for address prefixes and DHCPv6 is use for DNS only.
The relevant options in LWIP look to be CONFIG_LWIP_IPV6_RDNSS_MAX_DNS_SERVERS and CONFIG_LWIP_IPV6_DHCP6
Running on my IPv6 only network, it connects to the network and gets IPv6 addresses (I have multiple prefixes in RA, so it gets one general global and one ULA, as well as the link-local), but DNS is empty so HTTP isn't working:
[ 1682][D][WiFiNetworkManager.cpp:34] wifiOnEvent(): [Network] WiFi station start
[ 1700][D][WiFiNetworkManager.cpp:94] loop(): [Network] WiFi begin status 6
[ 1821][I][Core2Logger.cpp:198] log(): [Core2Logger] CORE2: WF STA connected
[ 3583][I][Core2Logger.cpp:198] log(): [Core2Logger] CORE2: WF STA IPv6 fe80:0000:0000:0000:0a3a:f2ff:fe65:db28
[ 3597][D][WiFiNetworkManager.cpp:47] wifiOnEvent(): [Network] IPv6 address type 2
[ 4585][I][Core2Logger.cpp:198] log(): [Core2Logger] CORE2: WF STA IPv6 2407:8800:bc61:1330:0a3a:f2ff:fe65:db28
[ 4599][I][Core2Logger.cpp:176] success(): [Core2Logger] Success
[ 4605][D][WiFiNetworkManager.cpp:47] wifiOnEvent(): [Network] IPv6 address type 1
[ 4620][I][Core2Logger.cpp:198] log(): [Core2Logger] CORE2: WF STA IPv6 fd7c:e25e:67e8:0030:0a3a:f2ff:fe65:db28
[ 4635][I][Core2Logger.cpp:176] success(): [Core2Logger] Success
[ 4641][D][WiFiNetworkManager.cpp:47] wifiOnEvent(): [Network] IPv6 address type 4
[ 18509][I][Core2Logger.cpp:198] log(): [Core2Logger] CORE2: Button 1, scenario 0, v0.1.0-150-g27c8f84-dev
[ 18523][I][Core2Logger.cpp:198] log(): [Core2Logger] CORE2: Global IPv6 2407:8800:bc61:1330:a3a:f2ff:fe65:db28
[ 18537][I][Core2Logger.cpp:198] log(): [Core2Logger] CORE2: IPv4 0.0.0.0
[ 18545][I][Core2Logger.cpp:198] log(): [Core2Logger] CORE2: Link-Local IPv6 fe80::a3a:f2ff:fe65:db28%st1
[ 18558][I][Core2Logger.cpp:198] log(): [Core2Logger] CORE2: DNS0 0.0.0.0
[ 18566][I][Core2Logger.cpp:198] log(): [Core2Logger] CORE2: DNS1 0.0.0.0
[ 18574][I][Core2Logger.cpp:198] log(): [Core2Logger] CORE2: URL: http://v4v6.ipv6-test.com/api/myip.php
[ 18605][D][WiFiGeneric.cpp:1649] hostByName(): Clearing DNS cache
[ 18611][E][WiFiGeneric.cpp:1678] hostByName(): DNS Failed for 'v4v6.ipv6-test.com' with error '-6' and result '0'
[ 18622][E][WiFiClient.cpp:258] connect(): connect on fd 48, errno: 118, "Host is unreachable"
[ 18631][D][HTTPClient.cpp:1163] connect(): failed connect to v4v6.ipv6-test.com:80
[ 18638][W][HTTPClient.cpp:1486] returnError(): error(-1): connection refused
[ 18645][E][Core2Logger.cpp:192] log(): [Core2Logger] CORE2: HTTP GET error -1: connection refused
Sketch
Debug Message
Other Steps to Reproduce
I am not sure if it is a LWIP configuration issue or if processing of DNS server addresses does not handle IPv6.
IPv6 is working in dual stack, although DNS only shows the IPv4 DNS server.
[ 1679][D][WiFiNetworkManager.cpp:34] wifiOnEvent(): [Network] WiFi station start
[ 1715][D][WiFiNetworkManager.cpp:94] loop(): [Network] WiFi begin status 6
[ 2012][I][Core2Logger.cpp:198] log(): [Core2Logger] CORE2: WF STA connected
[ 2356][I][Core2Logger.cpp:198] log(): [Core2Logger] CORE2: WF STA IPv4 192.168.1.147
[ 2366][I][Core2Logger.cpp:176] success(): [Core2Logger] Success
[ 3583][I][Core2Logger.cpp:198] log(): [Core2Logger] CORE2: WF STA IPv6 fe80:0000:0000:0000:0a3a:f2ff:fe65:db28
[ 3597][D][WiFiNetworkManager.cpp:47] wifiOnEvent(): [Network] IPv6 address type 2
[ 4585][I][Core2Logger.cpp:198] log(): [Core2Logger] CORE2: WF STA IPv6 2407:8800:bc61:1340:0a3a:f2ff:fe65:db28
[ 4599][I][Core2Logger.cpp:176] success(): [Core2Logger] Success
[ 4605][D][WiFiNetworkManager.cpp:47] wifiOnEvent(): [Network] IPv6 address type 1
[ 4620][I][Core2Logger.cpp:198] log(): [Core2Logger] CORE2: WF STA IPv6 fd7c:e25e:67e8:0040:0a3a:f2ff:fe65:db28
[ 4634][I][Core2Logger.cpp:176] success(): [Core2Logger] Success
[ 4640][D][WiFiNetworkManager.cpp:47] wifiOnEvent(): [Network] IPv6 address type 4
Requests to an IPv6 test dual stack endpoint do resolve, via the IPv4 DNS, to their IPv6 address with the endpoint reporting the remote client address (i.e. my address) as IPv6:
[ 36859][I][Core2Logger.cpp:198] log(): [Core2Logger] CORE2: Button 1, scenario 0, v0.1.0-150-g27c8f84-dev
[ 36872][I][Core2Logger.cpp:198] log(): [Core2Logger] CORE2: Global IPv6 2407:8800:bc61:1340:a3a:f2ff:fe65:db28
[ 36886][I][Core2Logger.cpp:198] log(): [Core2Logger] CORE2: IPv4 192.168.1.147
[ 36895][I][Core2Logger.cpp:198] log(): [Core2Logger] CORE2: Link-Local IPv6 fe80::a3a:f2ff:fe65:db28%st1
[ 36908][I][Core2Logger.cpp:198] log(): [Core2Logger] CORE2: DNS0 192.168.1.1
[ 36917][I][Core2Logger.cpp:198] log(): [Core2Logger] CORE2: DNS1 0.0.0.0
[ 36924][I][Core2Logger.cpp:198] log(): [Core2Logger] CORE2: URL: http://v4v6.ipv6-test.com/api/myip.php
[ 39165][I][Core2Logger.cpp:198] log(): [Core2Logger] CORE2: response=<2407:8800:bc61:1340:a3a:f2ff:fe65:db28>
[ 39180][I][Core2Logger.cpp:176] success(): [Core2Logger] Success
I have checked existing issues, online documentation and the Troubleshooting Guide
The text was updated successfully, but these errors were encountered: