編集：結局Pulseaudioを使用してネットワーク経由でリモートのRaspberry Piにオーディオストリームを送信する別の方法（Avahiを使用しない方法）... それで、私はこの質問に興味を失いました。問題が極めて興味深いと思わない限り、答える必要はありません。私の最初の試みが誰かの役に立つかもしれないので、とにかくここに残しておきます。
私は、Rapsberry Pi を Pulseaudio リモート シンクとして設定しています。同じ LAN 上の別のホストで、'export PULSE_SERVER="[2001:470:ca90:4:ba27:ebff:fee2:ada9]" && mplayer sound.mp3' を実行すると、音楽をリモートで再生できます。これまでのところ、順調です。IPv4 でも問題なく動作します。クライアント ホストは Debian Jessie、サーバー ホストは Raspbian Jessie です。
Pulseaudio はシステム モードで動作します。ヘッドレス シンクは、Pulseaudio が適している数少ないケースの 1 つです。system.pa への追加は次のとおりです。
load-module module-native-protocol-tcp auth-ip-acl=127.0.0.1;10.4.0.0/24;2001:470:ca90:4:21b:21ff:feaa:99c9
load-module module-zeroconf-publish
運用開始後は 10.4.0.0/24 を削除しますが、現時点ではこのサブネット上のどのステーションからでもテストできるようにしたいと考えています。
リモート Pulseaudio シンクを選択するには、サーバーの avahi がそのサービスを正しくアドバタイズする必要があります。これが現在の状況です。
ローカルのサーバー ホストでは、Pulseaudio サービスが正しくアドバタイズされているようです。
root@hornwall:~# avahi-browse -a -t
+ eth0 IPv6 pulse@hornwall: Sound Blaster X-Fi Go! Pro Analog Stereo PulseAudio Sound Sink local
+ eth0 IPv6 pulse@hornwall: bcm2835 ALSA Analog Stereo PulseAudio Sound Sink local
+ eth0 IPv4 pulse@hornwall: Sound Blaster X-Fi Go! Pro Analog Stereo PulseAudio Sound Sink local
+ eth0 IPv4 pulse@hornwall: bcm2835 ALSA Analog Stereo PulseAudio Sound Sink local
+ eth0 IPv6 pulse@hornwall: Sound Blaster X-Fi Go! Pro Analog Stereo PulseAudio Sound Source local
+ eth0 IPv4 pulse@hornwall: Sound Blaster X-Fi Go! Pro Analog Stereo PulseAudio Sound Source local
+ eth0 IPv6 pulse@hornwall PulseAudio Sound Server local
+ eth0 IPv4 pulse@hornwall PulseAudio Sound Server local
+ eth0 IPv6 hornwall [b8:27:eb:e2:ad:a9] Workstation local
+ eth0 IPv4 hornwall [b8:27:eb:e2:ad:a9] Workstation local
しかし、同じネットワーク上の他のホストは Pulseaudio サービスを見ることができません。
root@Kitandara:/etc/pulse# avahi-browse -a -t
+ eth1 IPv6 amour Remote Disk Management local
+ eth1 IPv4 amour Remote Disk Management local
+ eth1 IPv6 amour [54:04:a6:67:9b:53] Workstation local
+ eth1 IPv6 Kitandara [00:1b:21:aa:99:c9] Workstation local
+ eth1 IPv4 amour [54:04:a6:67:9b:53] Workstation local
+ eth1 IPv4 Kitandara [00:1b:21:aa:99:c9] Workstation local
+ eth2 IPv6 Kitandara [00:1b:21:aa:99:cd] Workstation local
+ eth2 IPv4 Kitandara [00:1b:21:aa:99:cd] Workstation local
root@amour:~# avahi-browse -a -t
+ eth0 IPv6 amour Remote Disk Management local
+ eth0 IPv4 amour Remote Disk Management local
+ eth0 IPv6 amour [54:04:a6:67:9b:53] Workstation local
+ eth0 IPv6 Kitandara [00:1b:21:aa:99:c9] Workstation local
+ eth0 IPv4 amour [54:04:a6:67:9b:53] Workstation local
+ eth0 IPv4 Kitandara [00:1b:21:aa:99:c9] Workstation local
root@waga:~# avahi-browse -a -t
+ eth0 IPv6 waga Remote Disk Management local
+ eth0 IPv4 waga Remote Disk Management local
+ eth0 IPv6 waga [54:04:a6:67:9b:b7] Workstation local
+ eth0 IPv4 waga [54:04:a6:67:9b:b7] Workstation local
これら 3 つの例は、他のワークステーションです。奇妙なことに、そのうちの 1 つは他のワークステーションを認識しませんが、同様に構成されていると思います。
関係する 4 つのホスト (Raspberry Pi と 4 つの標準的な Intel コンピュータ) はすべて同じ Ethernet セグメント上にあり、間にルーターはありません。IPv6 と IPv4 の両方の接続は正常です。どちらのホストにも iptables はありません。これらのホストはすべて同様の Avahi 構成を持ち、利用可能なすべてのインターフェイスで IPv4 と IPv6 の両方を使用しています。
root@Kitandara:/etc/pulse# grep -v ^# /etc/avahi/avahi-daemon.conf
[server]
use-ipv4=yes
use-ipv6=yes
ratelimit-interval-usec=1000000
ratelimit-burst=1000
[wide-area]
enable-wide-area=yes
[publish]
[reflector]
[rlimits]
rlimit-core=0
rlimit-data=4194304
rlimit-fsize=0
rlimit-nofile=768
rlimit-stack=4194304
rlimit-nproc=3
さて...今、私は行き詰まっています - どちらに促すべきでしょうか?
@grawity の提案により、エーテルの向こう側に何があるのかについての洞察がここにあります...
Pulseaudio シンクの eth0 をリッスンし、そこで avahi デーモンを再起動すると、期待どおりの MDNS パケットが大量に発生します。
56 12.938605 2001:470:ca90:4:ba27:ebff:fee2:ada9 -> ff02::fb MDNS 450 Standard query 0x0000 ANY hornwall [b8:27:eb:e2:ad:a9]._workstation._tcp.local, "QM" question ANY pulse@hornwall._pulse-server._tcp.local, "QM" question
57 12.939394 10.4.0.202 -> 224.0.0.251 MDNS 430 Standard query 0x0000 ANY hornwall [b8:27:eb:e2:ad:a9]._workstation._tcp.local, "QM" question ANY pulse@hornwall._pulse-server._tcp.local, "QM" question
58 12.994690 2001:470:ca90:4:ba27:ebff:fee2:ada9 -> ff02::fb MDNS 849 Standard query 0x0000 ANY pulse@hornwall: Sound Blaster X-Fi Go! Pro Analog Stereo._pulse-source._tcp.local, "QM" question ANY pulse@hornwall: bcm2835 ALSA Analog Stereo._pulse-sink._tcp.local, "QM" question
59 12.995632 10.4.0.202 -> 224.0.0.251 MDNS 829 Standard query 0x0000 ANY pulse@hornwall: Sound Blaster X-Fi Go! Pro Analog Stereo._pulse-source._tcp.local, "QM" question ANY pulse@hornwall: bcm2835 ALSA Analog Stereo._pulse-sink._tcp.local, "QM" question
60 13.019775 2001:470:ca90:4:ba27:ebff:fee2:ada9 -> ff02::fb MDNS 652 Standard query 0x0000 ANY pulse@hornwall: bcm2835 ALSA Analog Stereo._pulse-sink._tcp.local, "QM" question ANY pulse@hornwall: Sound Blaster X-Fi Go! Pro Analog Stereo._pulse-sink._tcp.local, "QM" question
61 13.020848 10.4.0.202 -> 224.0.0.251 MDNS 632 Standard query 0x0000 ANY pulse@hornwall: bcm2835 ALSA Analog Stereo._pulse-sink._tcp.local, "QM" question ANY pulse@hornwall: Sound Blaster X-Fi Go! Pro Analog Stereo._pulse-sink._tcp.local, "QM" question
62 13.049454 2001:470:ca90:4:ba27:ebff:fee2:ada9 -> ff02::fb MDNS 738 Standard query 0x0000 ANY pulse@hornwall: Sound Blaster X-Fi Go! Pro Analog Stereo._pulse-sink._tcp.local, "QM" question
63 13.050227 10.4.0.202 -> 224.0.0.251 MDNS 718 Standard query 0x0000 ANY pulse@hornwall: Sound Blaster X-Fi Go! Pro Analog Stereo._pulse-sink._tcp.local, "QM" question
64 13.188819 2001:470:ca90:4:ba27:ebff:fee2:ada9 -> ff02::fb MDNS 450 Standard query 0x0000 ANY hornwall [b8:27:eb:e2:ad:a9]._workstation._tcp.local, "QM" question ANY pulse@hornwall._pulse-server._tcp.local, "QM" question
65 13.189735 10.4.0.202 -> 224.0.0.251 MDNS 430 Standard query 0x0000 ANY hornwall [b8:27:eb:e2:ad:a9]._workstation._tcp.local, "QM" question ANY pulse@hornwall._pulse-server._tcp.local, "QM" question
66 13.245302 2001:470:ca90:4:ba27:ebff:fee2:ada9 -> ff02::fb MDNS 849 Standard query 0x0000 ANY pulse@hornwall: Sound Blaster X-Fi Go! Pro Analog Stereo._pulse-source._tcp.local, "QM" question ANY pulse@hornwall: bcm2835 ALSA Analog Stereo._pulse-sink._tcp.local, "QM" question
67 13.246325 10.4.0.202 -> 224.0.0.251 MDNS 829 Standard query 0x0000 ANY pulse@hornwall: Sound Blaster X-Fi Go! Pro Analog Stereo._pulse-source._tcp.local, "QM" question ANY pulse@hornwall: bcm2835 ALSA Analog Stereo._pulse-sink._tcp.local, "QM" question
68 13.270384 2001:470:ca90:4:ba27:ebff:fee2:ada9 -> ff02::fb MDNS 652 Standard query 0x0000 ANY pulse@hornwall: bcm2835 ALSA Analog Stereo._pulse-sink._tcp.local, "QM" question ANY pulse@hornwall: Sound Blaster X-Fi Go! Pro Analog Stereo._pulse-sink._tcp.local, "QM" question
69 13.271250 10.4.0.202 -> 224.0.0.251 MDNS 632 Standard query 0x0000 ANY pulse@hornwall: bcm2835 ALSA Analog Stereo._pulse-sink._tcp.local, "QM" question ANY pulse@hornwall: Sound Blaster X-Fi Go! Pro Analog Stereo._pulse-sink._tcp.local, "QM" question
70 13.299927 2001:470:ca90:4:ba27:ebff:fee2:ada9 -> ff02::fb MDNS 738 Standard query 0x0000 ANY pulse@hornwall: Sound Blaster X-Fi Go! Pro Analog Stereo._pulse-sink._tcp.local, "QM" question
71 13.300792 10.4.0.202 -> 224.0.0.251 MDNS 718 Standard query 0x0000 ANY pulse@hornwall: Sound Blaster X-Fi Go! Pro Analog Stereo._pulse-sink._tcp.local, "QM" question
72 13.439241 2001:470:ca90:4:ba27:ebff:fee2:ada9 -> ff02::fb MDNS 450 Standard query 0x0000 ANY hornwall [b8:27:eb:e2:ad:a9]._workstation._tcp.local, "QM" question ANY pulse@hornwall._pulse-server._tcp.local, "QM" question
73 13.440068 10.4.0.202 -> 224.0.0.251 MDNS 430 Standard query 0x0000 ANY hornwall [b8:27:eb:e2:ad:a9]._workstation._tcp.local, "QM" question ANY pulse@hornwall._pulse-server._tcp.local, "QM" question
74 13.496557 2001:470:ca90:4:ba27:ebff:fee2:ada9 -> ff02::fb MDNS 849 Standard query 0x0000 ANY pulse@hornwall: Sound Blaster X-Fi Go! Pro Analog Stereo._pulse-source._tcp.local, "QM" question ANY pulse@hornwall: bcm2835 ALSA Analog Stereo._pulse-sink._tcp.local, "QM" question
75 13.497498 10.4.0.202 -> 224.0.0.251 MDNS 829 Standard query 0x0000 ANY pulse@hornwall: Sound Blaster X-Fi Go! Pro Analog Stereo._pulse-source._tcp.local, "QM" question ANY pulse@hornwall: bcm2835 ALSA Analog Stereo._pulse-sink._tcp.local, "QM" question
76 13.521724 2001:470:ca90:4:ba27:ebff:fee2:ada9 -> ff02::fb MDNS 652 Standard query 0x0000 ANY pulse@hornwall: bcm2835 ALSA Analog Stereo._pulse-sink._tcp.local, "QM" question ANY pulse@hornwall: Sound Blaster X-Fi Go! Pro Analog Stereo._pulse-sink._tcp.local, "QM" question
77 13.522523 10.4.0.202 -> 224.0.0.251 MDNS 632 Standard query 0x0000 ANY pulse@hornwall: bcm2835 ALSA Analog Stereo._pulse-sink._tcp.local, "QM" question ANY pulse@hornwall: Sound Blaster X-Fi Go! Pro Analog Stereo._pulse-sink._tcp.local, "QM" question
78 13.551102 2001:470:ca90:4:ba27:ebff:fee2:ada9 -> ff02::fb MDNS 738 Standard query 0x0000 ANY pulse@hornwall: Sound Blaster X-Fi Go! Pro Analog Stereo._pulse-sink._tcp.local, "QM" question
79 13.551881 10.4.0.202 -> 224.0.0.251 MDNS 718 Standard query 0x0000 ANY pulse@hornwall: Sound Blaster X-Fi Go! Pro Analog Stereo._pulse-sink._tcp.local, "QM" question
80 13.640087 10.4.0.202 -> 224.0.0.251 MDNS 243 Standard query response 0x0000 TXT, cache flush PTR hornwall [b8:27:eb:e2:ad:a9]._workstation._tcp.local SRV, cache flush 0 0 9 hornwall.local AAAA, cache flush 2001:470:ca90:4:ba27:ebff:fee2:ada9 A, cache flush 10.4.0.202 PTR _workstation._tcp.local
81 13.641352 2001:470:ca90:4:ba27:ebff:fee2:ada9 -> ff02::fb MDNS 247 Standard query response 0x0000 TXT, cache flush PTR hornwall [b8:27:eb:e2:ad:a9]._workstation._tcp.local SRV, cache flush 0 0 9 hornwall.local AAAA, cache flush 2001:470:ca90:4:ba27:ebff:fee2:ada9 PTR _workstation._tcp.local
82 13.683214 10.4.0.202 -> 224.0.0.251 MDNS 394 Standard query response 0x0000 TXT, cache flush PTR pulse@hornwall._pulse-server._tcp.local SRV, cache flush 0 0 4713 hornwall.local PTR _pulse-server._tcp.local
83 13.684306 2001:470:ca90:4:ba27:ebff:fee2:ada9 -> ff02::fb MDNS 414 Standard query response 0x0000 TXT, cache flush PTR pulse@hornwall._pulse-server._tcp.local SRV, cache flush 0 0 4713 hornwall.local PTR _pulse-server._tcp.local
84 13.700770 10.4.0.202 -> 224.0.0.251 MDNS 849 Standard query response 0x0000 TXT, cache flush PTR pulse@hornwall: Sound Blaster X-Fi Go! Pro Analog Stereo._pulse-source._tcp.local SRV, cache flush 0 0 4713 hornwall.local PTR _pulse-source._tcp.local PTR pulse@hornwall: Sound Blaster X-Fi Go! Pro Analog Stereo._pulse-source._tcp.local PTR pulse@hornwall: Sound Blaster X-Fi Go! Pro Analog Stereo._pulse-source._tcp.local
85 13.702406 2001:470:ca90:4:ba27:ebff:fee2:ada9 -> ff02::fb MDNS 869 Standard query response 0x0000 TXT, cache flush PTR pulse@hornwall: Sound Blaster X-Fi Go! Pro Analog Stereo._pulse-source._tcp.local SRV, cache flush 0 0 4713 hornwall.local PTR _pulse-source._tcp.local PTR pulse@hornwall: Sound Blaster X-Fi Go! Pro Analog Stereo._pulse-source._tcp.local PTR pulse@hornwall: Sound Blaster X-Fi Go! Pro Analog Stereo._pulse-source._tcp.local
86 13.725697 10.4.0.202 -> 224.0.0.251 MDNS 643 Standard query response 0x0000 TXT, cache flush PTR pulse@hornwall: bcm2835 ALSA Analog Stereo._pulse-sink._tcp.local SRV, cache flush 0 0 4713 hornwall.local PTR _pulse-sink._tcp.local PTR pulse@hornwall: bcm2835 ALSA Analog Stereo._pulse-sink._tcp.local
87 13.727151 2001:470:ca90:4:ba27:ebff:fee2:ada9 -> ff02::fb MDNS 663 Standard query response 0x0000 TXT, cache flush PTR pulse@hornwall: bcm2835 ALSA Analog Stereo._pulse-sink._tcp.local SRV, cache flush 0 0 4713 hornwall.local PTR _pulse-sink._tcp.local PTR pulse@hornwall: bcm2835 ALSA Analog Stereo._pulse-sink._tcp.local
88 13.762306 10.4.0.202 -> 224.0.0.251 MDNS 784 Standard query response 0x0000 TXT, cache flush PTR pulse@hornwall: Sound Blaster X-Fi Go! Pro Analog Stereo._pulse-sink._tcp.local SRV, cache flush 0 0 4713 hornwall.local PTR pulse@hornwall: Sound Blaster X-Fi Go! Pro Analog Stereo._pulse-sink._tcp.local
89 13.763689 2001:470:ca90:4:ba27:ebff:fee2:ada9 -> ff02::fb MDNS 804 Standard query response 0x0000 TXT, cache flush PTR pulse@hornwall: Sound Blaster X-Fi Go! Pro Analog Stereo._pulse-sink._tcp.local SRV, cache flush 0 0 4713 hornwall.local PTR pulse@hornwall: Sound Blaster X-Fi Go! Pro Analog Stereo._pulse-sink._tcp.local
90 13.872390 10.4.0.202 -> 224.0.0.251 MDNS 187 Standard query response 0x0000 PTR, cache flush hornwall.local PTR, cache flush hornwall.local
91 13.873522 2001:470:ca90:4:ba27:ebff:fee2:ada9 -> ff02::fb MDNS 174 Standard query response 0x0000 PTR, cache flush hornwall.local
92 13.895013 10.4.0.202 -> 224.0.0.251 MDNS 93 Standard query response 0x0000 HINFO, cache flush ARMV6L LINUX
93 13.895711 2001:470:ca90:4:ba27:ebff:fee2:ada9 -> ff02::fb MDNS 113 Standard query response 0x0000 HINFO, cache flush ARMV6L LINUX
94 14.685743 10.4.0.202 -> 224.0.0.251 MDNS 243 Standard query response 0x0000 TXT, cache flush PTR hornwall [b8:27:eb:e2:ad:a9]._workstation._tcp.local SRV, cache flush 0 0 9 hornwall.local AAAA, cache flush 2001:470:ca90:4:ba27:ebff:fee2:ada9 A, cache flush 10.4.0.202 PTR _workstation._tcp.local
95 14.686990 2001:470:ca90:4:ba27:ebff:fee2:ada9 -> ff02::fb MDNS 247 Standard query response 0x0000 TXT, cache flush PTR hornwall [b8:27:eb:e2:ad:a9]._workstation._tcp.local SRV, cache flush 0 0 9 hornwall.local AAAA, cache flush 2001:470:ca90:4:ba27:ebff:fee2:ada9 PTR _workstation._tcp.local
96 14.727907 10.4.0.202 -> 224.0.0.251 MDNS 394 Standard query response 0x0000 TXT, cache flush PTR pulse@hornwall._pulse-server._tcp.local SRV, cache flush 0 0 4713 hornwall.local PTR _pulse-server._tcp.local
97 14.729184 2001:470:ca90:4:ba27:ebff:fee2:ada9 -> ff02::fb MDNS 414 Standard query response 0x0000 TXT, cache flush PTR pulse@hornwall._pulse-server._tcp.local SRV, cache flush 0 0 4713 hornwall.local PTR _pulse-server._tcp.local
98 14.745767 10.4.0.202 -> 224.0.0.251 MDNS 849 Standard query response 0x0000 TXT, cache flush PTR pulse@hornwall: Sound Blaster X-Fi Go! Pro Analog Stereo._pulse-source._tcp.local SRV, cache flush 0 0 4713 hornwall.local PTR _pulse-source._tcp.local PTR pulse@hornwall: Sound Blaster X-Fi Go! Pro Analog Stereo._pulse-source._tcp.local PTR pulse@hornwall: Sound Blaster X-Fi Go! Pro Analog Stereo._pulse-source._tcp.local
99 14.747376 2001:470:ca90:4:ba27:ebff:fee2:ada9 -> ff02::fb MDNS 869 Standard query response 0x0000 TXT, cache flush PTR pulse@hornwall: Sound Blaster X-Fi Go! Pro Analog Stereo._pulse-source._tcp.local SRV, cache flush 0 0 4713 hornwall.local PTR _pulse-source._tcp.local PTR pulse@hornwall: Sound Blaster X-Fi Go! Pro Analog Stereo._pulse-source._tcp.local PTR pulse@hornwall: Sound Blaster X-Fi Go! Pro Analog Stereo._pulse-source._tcp.local
100 14.769576 10.4.0.202 -> 224.0.0.251 MDNS 629 Standard query response 0x0000 TXT, cache flush SRV, cache flush 0 0 4713 hornwall.local PTR _pulse-sink._tcp.local PTR pulse@hornwall: bcm2835 ALSA Analog Stereo._pulse-sink._tcp.local
101 14.770904 2001:470:ca90:4:ba27:ebff:fee2:ada9 -> ff02::fb MDNS 649 Standard query response 0x0000 TXT, cache flush SRV, cache flush 0 0 4713 hornwall.local PTR _pulse-sink._tcp.local PTR pulse@hornwall: bcm2835 ALSA Analog Stereo._pulse-sink._tcp.local
102 14.807296 10.4.0.202 -> 224.0.0.251 MDNS 841 Standard query response 0x0000 TXT, cache flush PTR pulse@hornwall: Sound Blaster X-Fi Go! Pro Analog Stereo._pulse-sink._tcp.local SRV, cache flush 0 0 4713 hornwall.local PTR pulse@hornwall: Sound Blaster X-Fi Go! Pro Analog Stereo._pulse-sink._tcp.local PTR pulse@hornwall: bcm2835 ALSA Analog Stereo._pulse-sink._tcp.local
103 14.809329 2001:470:ca90:4:ba27:ebff:fee2:ada9 -> ff02::fb MDNS 861 Standard query response 0x0000 TXT, cache flush PTR pulse@hornwall: Sound Blaster X-Fi Go! Pro Analog Stereo._pulse-sink._tcp.local SRV, cache flush 0 0 4713 hornwall.local PTR pulse@hornwall: Sound Blaster X-Fi Go! Pro Analog Stereo._pulse-sink._tcp.local PTR pulse@hornwall: bcm2835 ALSA Analog Stereo._pulse-sink._tcp.local
104 15.917331 10.4.0.202 -> 224.0.0.251 MDNS 231 Standard query response 0x0000 PTR, cache flush hornwall.local A, cache flush 10.4.0.202 PTR, cache flush hornwall.local AAAA, cache flush 2001:470:ca90:4:ba27:ebff:fee2:ada9
105 15.918460 2001:470:ca90:4:ba27:ebff:fee2:ada9 -> ff02::fb MDNS 202 Standard query response 0x0000 PTR, cache flush hornwall.local AAAA, cache flush 2001:470:ca90:4:ba27:ebff:fee2:ada9
106 15.939179 10.4.0.202 -> 224.0.0.251 MDNS 93 Standard query response 0x0000 HINFO, cache flush ARMV6L LINUX
107 15.942478 2001:470:ca90:4:ba27:ebff:fee2:ada9 -> ff02::fb MDNS 113 Standard query response 0x0000 HINFO, cache flush ARMV6L LINUX
108 16.730511 10.4.0.202 -> 224.0.0.251 MDNS 243 Standard query response 0x0000 TXT, cache flush PTR hornwall [b8:27:eb:e2:ad:a9]._workstation._tcp.local SRV, cache flush 0 0 9 hornwall.local AAAA, cache flush 2001:470:ca90:4:ba27:ebff:fee2:ada9 A, cache flush 10.4.0.202 PTR _workstation._tcp.local
109 16.731652 2001:470:ca90:4:ba27:ebff:fee2:ada9 -> ff02::fb MDNS 247 Standard query response 0x0000 TXT, cache flush PTR hornwall [b8:27:eb:e2:ad:a9]._workstation._tcp.local SRV, cache flush 0 0 9 hornwall.local AAAA, cache flush 2001:470:ca90:4:ba27:ebff:fee2:ada9 PTR _workstation._tcp.local
110 16.772372 10.4.0.202 -> 224.0.0.251 MDNS 394 Standard query response 0x0000 TXT, cache flush PTR pulse@hornwall._pulse-server._tcp.local SRV, cache flush 0 0 4713 hornwall.local PTR _pulse-server._tcp.local
111 16.773610 2001:470:ca90:4:ba27:ebff:fee2:ada9 -> ff02::fb MDNS 414 Standard query response 0x0000 TXT, cache flush PTR pulse@hornwall._pulse-server._tcp.local SRV, cache flush 0 0 4713 hornwall.local PTR _pulse-server._tcp.local
112 16.789610 10.4.0.202 -> 224.0.0.251 MDNS 835 Standard query response 0x0000 TXT, cache flush SRV, cache flush 0 0 4713 hornwall.local PTR _pulse-source._tcp.local PTR pulse@hornwall: Sound Blaster X-Fi Go! Pro Analog Stereo._pulse-source._tcp.local PTR pulse@hornwall: Sound Blaster X-Fi Go! Pro Analog Stereo._pulse-source._tcp.local
113 16.791221 2001:470:ca90:4:ba27:ebff:fee2:ada9 -> ff02::fb MDNS 855 Standard query response 0x0000 TXT, cache flush SRV, cache flush 0 0 4713 hornwall.local PTR _pulse-source._tcp.local PTR pulse@hornwall: Sound Blaster X-Fi Go! Pro Analog Stereo._pulse-source._tcp.local PTR pulse@hornwall: Sound Blaster X-Fi Go! Pro Analog Stereo._pulse-source._tcp.local
114 16.814388 10.4.0.202 -> 224.0.0.251 MDNS 714 Standard query response 0x0000 TXT, cache flush SRV, cache flush 0 0 4713 hornwall.local PTR _pulse-sink._tcp.local PTR pulse@hornwall: bcm2835 ALSA Analog Stereo._pulse-sink._tcp.local PTR pulse@hornwall: Sound Blaster X-Fi Go! Pro Analog Stereo._pulse-source._tcp.local
115 16.815894 2001:470:ca90:4:ba27:ebff:fee2:ada9 -> ff02::fb MDNS 734 Standard query response 0x0000 TXT, cache flush SRV, cache flush 0 0 4713 hornwall.local PTR _pulse-sink._tcp.local PTR pulse@hornwall: bcm2835 ALSA Analog Stereo._pulse-sink._tcp.local PTR pulse@hornwall: Sound Blaster X-Fi Go! Pro Analog Stereo._pulse-source._tcp.local
116 16.850830 10.4.0.202 -> 224.0.0.251 MDNS 827 Standard query response 0x0000 TXT, cache flush SRV, cache flush 0 0 4713 hornwall.local PTR pulse@hornwall: Sound Blaster X-Fi Go! Pro Analog Stereo._pulse-sink._tcp.local PTR pulse@hornwall: bcm2835 ALSA Analog Stereo._pulse-sink._tcp.local
117 16.852697 2001:470:ca90:4:ba27:ebff:fee2:ada9 -> ff02::fb MDNS 847 Standard query response 0x0000 TXT, cache flush SRV, cache flush 0 0 4713 hornwall.local PTR pulse@hornwall: Sound Blaster X-Fi Go! Pro Analog Stereo._pulse-sink._tcp.local PTR pulse@hornwall: bcm2835 ALSA Analog Stereo._pulse-sink._tcp.local
118 16.891486 10.4.0.202 -> 224.0.0.251 MDNS 147 Standard query response 0x0000 PTR pulse@hornwall: Sound Blaster X-Fi Go! Pro Analog Stereo._pulse-sink._tcp.local
119 16.892429 2001:470:ca90:4:ba27:ebff:fee2:ada9 -> ff02::fb MDNS 167 Standard query response 0x0000 PTR pulse@hornwall: Sound Blaster X-Fi Go! Pro Analog Stereo._pulse-sink._tcp.local
ポート 5353 の ff02::fb および 224.0.0.251 宛てのパケットは、理論上は当然発生するはずのものであり、これは良いことです。
しかしその間、他のステーションは何も観測していません - 単一の MDNS パケットも。
しばらくしてワークステーション上で次の画面が表示されます。
root@amour:~# tshark -i eth0 -f "port 5353"
1 0.000000 2001:470:ca90:4:21b:21ff:feaa:99c9 -> ff02::fb MDNS 140 Standard query 0x0000 PTR _pulse-sink._tcp.local, "QM" question PTR _non-monitor._sub._pulse-source._tcp.local, "QM" question
2 0.000031 10.4.0.124 -> 224.0.0.251 MDNS 120 Standard query 0x0000 PTR _pulse-sink._tcp.local, "QM" question PTR _non-monitor._sub._pulse-source._tcp.local, "QM" question
ローカルルーターでは次のようになります。
root@arua:~# tshark -i vlan4 -f "port 5353"
1 0.000000 2001:470:ca90:4:21b:21ff:feaa:99c9 -> ff02::fb MDNS 140 Standard query 0x0000 PTR _pulse-sink._tcp.local, "QM" question PTR _non-monitor._sub._pulse-source._tcp.local, "QM" question
2 0.000135 10.4.0.124 -> 224.0.0.251 MDNS 120 Standard query 0x0000 PTR _pulse-sink._tcp.local, "QM" question PTR _non-monitor._sub._pulse-source._tcp.local, "QM" question
しかし、ここで宣伝されている Pulseaudio シンクは別のステーションに属しており、上記の大きなバーストをブロードキャストした Raspberry pi のものではありません。その別のシンク宣伝ステーションで avahi を再起動すると、正しい MDNS バーストが両方の先行ホスト (amour と arua) で表示されます... しかし、他のワークステーション (waga) や Raspberry Pi (hornwall) では表示されません。amour と waga は構成が非常に似ているため、これは奇妙ですが、何かが異なっている可能性があります。
では、なぜ他のステーションは Raspberry Pi がブロードキャストしていると思われる MDNS パケットを認識できないのでしょうか。他のステーションによってブロードキャストされたシンク アドバタイズ MDNS パケットを 2 つのステーションだけが認識するのはなぜでしょうか。受信側で構成ミスがある可能性はありますか。