Failed to resolve hostname Failed to resolve mDNS address

[VH-Tech]

Hi,

I am able to see the video feed perfectly when both my devices are on the same WiFi. But as soon as I connect them to different networks I get the following error :

INFO /home/vatsal/libpeer/src/mdns.c 161 Failed to resolve hostname
WARN /home/vatsal/libpeer/src/ice.c 125 Failed to resolve mDNS address

Complete Logs :

I (905) webrtc: [APP] Startup..
I (905) webrtc: [APP] Free memory: 2371908 bytes
I (915) webrtc: [APP] IDF version: v5.2.2
I (945) example_connect: Start example_connect.
I (945) pp: pp rom version: e7ae62f
I (945) net80211: net80211 rom version: e7ae62f
I (955) wifi:wifi driver task: 3fcb9914, prio:23, stack:6656, core=0
I (965) wifi:wifi firmware version: 3e0076f
I (965) wifi:wifi certification version: v7.0
I (965) wifi:config NVS flash: enabled
I (965) wifi:config nano formating: disabled
I (965) wifi:Init data frame dynamic rx buffer num: 32
I (975) wifi:Init static rx mgmt buffer num: 5
I (975) wifi:Init management short buffer num: 32
I (985) wifi:Init static tx buffer num: 32
I (985) wifi:Init tx cache buffer num: 32
I (985) wifi:Init static tx FG buffer num: 2
I (995) wifi:Init static rx buffer size: 1600
I (995) wifi:Init static rx buffer num: 10
I (1005) wifi:Init dynamic rx buffer num: 32
I (1005) wifi_init: rx ba win: 6
I (1005) wifi_init: tcpip mbox: 32
I (1015) wifi_init: udp mbox: 6
I (1015) wifi_init: tcp mbox: 6
I (1025) wifi_init: tcp tx win: 5744
I (1025) wifi_init: tcp rx win: 5744
I (1025) wifi_init: tcp mss: 1440
I (1035) wifi_init: WiFi IRAM OP enabled
I (1035) wifi_init: WiFi RX IRAM OP enabled
I (1045) phy_init: phy_version 670,b7bc9b9,Apr 30 2024,10:54:13
I (1085) wifi:mode : sta (7c:df:a1:ed:6b:88)
I (1085) wifi:enable tsf
I (1085) example_connect: Connecting to Vatsal...
I (1095) example_connect: Waiting for IP(s)
I (3875) wifi:new:<2,0>, old:<1,0>, ap:<255,255>, sta:<2,0>, prof:1
I (3875) wifi:state: init -> auth (b0)
I (3875) wifi:state: auth -> assoc (0)
I (3885) wifi:state: assoc -> run (10)
I (4105) wifi:connected with Vatsal, aid = 1, channel 2, BW20, bssid = 3e:06:29:91:5f:59
I (4105) wifi:security: WPA2-PSK, phy: bgn, rssi: -10
I (4105) wifi:pm start, type: 1

I (4105) wifi:dp: 1, bi: 102400, li: 3, scale listen interval from 307200 us to 307200 us
I (4115) wifi:set rx beacon pti, rx_bcn_pti: 0, bcn_timeout: 25000, mt_pti: 0, mt_time: 10000
I (4125) wifi:dp: 2, bi: 102400, li: 4, scale listen interval from 307200 us to 409600 us
I (4135) wifi:AP's beacon interval = 102400 us, DTIM period = 2
I (4175) wifi:<ba-add>idx:0 (ifx:0, 3e:06:29:91:5f:59), tid:0, ssn:0, winSize:64
I (5135) esp_netif_handlers: example_netif_sta ip: 10.31.149.220, mask: 255.255.255.0, gw: 10.31.149.162
I (5135) example_connect: Got IPv4 event: Interface "example_netif_sta" address: 10.31.149.220
I (5145) example_common: Connected to example_netif_sta
I (5145) example_common: - IPv4 address: 10.31.149.220,
I (5195) s3 ll_cam: DMA Channel=1
I (5195) cam_hal: cam init ok
I (5195) sccb: pin_sda 15 pin_scl 16
I (5195) sccb: sccb_i2c_port=1
I (5205) camera: Detected camera at address=0x30
I (5205) camera: Detected OV2640 camera
I (5205) camera: Camera PID=0x26 VER=0x42 MIDL=0x7f MIDH=0xa2
I (5285) cam_hal: buffer_size: 16384, half_buffer_size: 1024, node_buffer_size: 1024, node_cnt: 16, total_cnt: 60
I (5285) cam_hal: Allocating 61440 Byte frame buffer in PSRAM
I (5295) cam_hal: Allocating 61440 Byte frame buffer in PSRAM
I (5305) cam_hal: cam config ok
I (5305) ov2640: Set PLL: clk_2x: 0, clk_div: 0, pclk_auto: 0, pclk_div: 8
INFO    /home/vatsal/libpeer/src/agent.c        32      create IPv4 UDP socket: 54
INFO    /home/vatsal/libpeer/src/peer_connection.c      175     Datachannel allocates heap size: 102400
INFO    /home/vatsal/libpeer/src/peer_connection.c      182     Audio allocates heap size: 8096
INFO    /home/vatsal/libpeer/src/peer_signaling.c       134     Host: libpeer.com, Port: 8883, Path: /public/shiny-brave-tiger
I (5425) wifi:<ba-add>idx:1 (ifx:0, 3e:06:29:91:5f:59), tid:7, ssn:2, winSize:64
INFO    /home/vatsal/libpeer/src/ports.c        140     Resolved libpeer.com -> 5.78.82.24
INFO    /home/vatsal/libpeer/src/socket.c       230     Connecting to server: 5.78.82.24:8883
INFO    /home/vatsal/libpeer/src/socket.c       236     Server is connected
INFO    /home/vatsal/libpeer/src/ssl_transport.c        106     start to handshake
INFO    /home/vatsal/libpeer/src/ssl_transport.c        114     handshake success
INFO    /home/vatsal/libpeer/src/peer_signaling.c       440     MQTT_Connect succeeded.
INFO    /home/vatsal/libpeer/src/peer_signaling.c       456     Subscribing topic /public/shiny-brave-tiger/invoke
INFO    /home/vatsal/libpeer/src/peer_signaling.c       382     MQTT Subscribe succeeded.
I (10565) Camera: Camera Task Started
I (10565) webrtc: [APP] Free memory: 1886932 bytes
I (10565) webrtc: peer_connection_task started
============= Configuration =============
 URL   : mqtts://libpeer.com/public/shiny-brave-tiger
 Token : 
=========================================
I (82655) webrtc: PeerConnectionState: 1
INFO    /home/vatsal/libpeer/src/peer_connection.c      345     ice server: stun:stun.l.google.com:19302
INFO    /home/vatsal/libpeer/src/ports.c        140     Resolved stun.l.google.com -> 74.125.250.129
INFO    /home/vatsal/libpeer/src/agent.c        269     Resolved stun/turn server 74.125.250.129:19302
INFO    /home/vatsal/libpeer/src/mdns.c 161     Failed to resolve hostname
WARN    /home/vatsal/libpeer/src/ice.c  125     Failed to resolve mDNS address
I (140195) webrtc: PeerConnectionState: 2
I (180205) webrtc: PeerConnectionState: 5

[topworldcoder]

Did you configure STUN/TURN in libpeer's web html demo?
Two different wifi networks may prevent libpeer and the web from connecting directly (probably causing the result "Cannot resolve mDNS address"), but TURN can be used for relaying.

STUN/TURN configuration in libpeer's web html demo:
var pc = new RTCPeerConnection({
iceServers: [
{ urls: "stun:your_stun_turn_ip:your_stun_turn_port", },
{ urls: "stun:your_stun_turn_ip:your_stun_turn_port", username: "your_turn_username", credential: "your_turn_password", },
{ urls: "stun:stun.l.google.com:19302", },
],
});