我最近更換了我的 ISP，之後我在 Debian 10 上連接到互聯網時開始遇到一些問題。和我的手機（wifi）。在 Debian 上，互聯網可以工作幾秒鐘，足以加載一頁，但之後就不再工作了。我已經嘗試增加 MTU 值，因為看起來它可以幫助其他遇到此問題的人，但對我來說不起作用。另外，我使用我的筆記型電腦進行了測試，該筆記型電腦也安裝了 Debian 10，它可以工作。我使用有線和無線網路進行了測試。
dmesg |尾-20給我：
[ 13.976571] br-a16997434552: port 1(veth6622e95) entered forwarding state
[ 13.976619] eth0: renamed from vethdb50e9c
[ 13.996186] eth0: renamed from vethcbb270b
[ 14.044342] IPv6: ADDRCONF(NETDEV_CHANGE): br-a16997434552: link becomes ready
[ 14.044712] eth0: renamed from veth6bc5a88
[ 14.068466] IPv6: ADDRCONF(NETDEV_CHANGE): veth94bcb37: link becomes ready
[ 14.068523] br-bcf7ce342cb9: port 1(veth94bcb37) entered blocking state
[ 14.068527] br-bcf7ce342cb9: port 1(veth94bcb37) entered forwarding state
[ 14.068614] IPv6: ADDRCONF(NETDEV_CHANGE): vetha3f8b80: link becomes ready
[ 14.068658] br-f68c9df397fa: port 1(vetha3f8b80) entered blocking state
[ 14.068661] br-f68c9df397fa: port 1(vetha3f8b80) entered forwarding state
[ 14.068758] IPv6: ADDRCONF(NETDEV_CHANGE): br-bcf7ce342cb9: link becomes ready
[ 14.068836] IPv6: ADDRCONF(NETDEV_CHANGE): br-f68c9df397fa: link becomes ready
[ 14.069028] IPv6: ADDRCONF(NETDEV_CHANGE): vetha784882: link becomes ready
[ 14.069063] br-37692a4e723c: port 1(vetha784882) entered blocking state
[ 14.069065] br-37692a4e723c: port 1(vetha784882) entered forwarding state
[ 14.069117] IPv6: ADDRCONF(NETDEV_CHANGE): br-37692a4e723c: link becomes ready
[ 14.121290] r8169 0000:03:00.0 enp3s0: Link is Up - 1Gbps/Full - flow control off
[ 19.920051] snd_hda_codec_hdmi hdaudioC0D0: HDMI: invalid ELD data byte 20
[ 20.224017] snd_hda_codec_hdmi hdaudioC0D0: HDMI: invalid ELD data byte 20
獲取http://www.duckduckgo.com給我：
--2021-05-30 00:12:43-- http://www.duckduckgo.com/
Resolvendo www.duckduckgo.com (www.duckduckgo.com)... 191.235.123.80
Conectando-se a www.duckduckgo.com (www.duckduckgo.com)|191.235.123.80|:80... falhou: Tempo esgotado para conexão.
Tentando novamente.
--2021-05-30 00:13:23-- (tentativa: 2) http://www.duckduckgo.com/
Conectando-se a www.duckduckgo.com (www.duckduckgo.com)|191.235.123.80|:80... falhou: Tempo esgotado para conexão.
Tentando novamente.
--2021-05-30 00:13:57-- (tentativa: 3) http://www.duckduckgo.com/
Conectando-se a www.duckduckgo.com (www.duckduckgo.com)|191.235.123.80|:80... falhou: Tempo esgotado para conexão.
Tentando novamente.
--2021-05-30 00:14:31-- (tentativa: 4) http://www.duckduckgo.com/
Conectando-se a www.duckduckgo.com (www.duckduckgo.com)|191.235.123.80|:80... ^C
ip 路由取得 1.1.1.1給我：
1.1.1.1 via 192.168.0.1 dev enp3s0 src 192.168.0.102 uid 1000
cache
ip -br 連結； ip -br 位址； ip路由給我：
lo UNKNOWN 00:00:00:00:00:00 <LOOPBACK,UP,LOWER_UP>
enp3s0 UP 18:31:bf:b3:38:7d <BROADCAST,MULTICAST,UP,LOWER_UP>
br-9ca719aa01c7 DOWN 02:42:97:ea:72:b0 <NO-CARRIER,BROADCAST,MULTICAST,UP>
br-b97158ffcc3c DOWN 02:42:74:c5:64:57 <NO-CARRIER,BROADCAST,MULTICAST,UP>
docker0 DOWN 02:42:c9:ef:9e:71 <NO-CARRIER,BROADCAST,MULTICAST,UP>
br-55cb011b3e0d DOWN 02:42:04:1a:72:0a <NO-CARRIER,BROADCAST,MULTICAST,UP>
br-777211ddb717 DOWN 02:42:4f:08:86:92 <NO-CARRIER,BROADCAST,MULTICAST,UP>
br-a16997434552 UP 02:42:55:72:e0:b8 <BROADCAST,MULTICAST,UP,LOWER_UP>
br-bcf7ce342cb9 UP 02:42:f1:f0:8e:7b <BROADCAST,MULTICAST,UP,LOWER_UP>
br-d4e258cd683a DOWN 02:42:05:9b:2d:27 <NO-CARRIER,BROADCAST,MULTICAST,UP>
br-4b3e4deacee9 DOWN 02:42:9d:07:40:5b <NO-CARRIER,BROADCAST,MULTICAST,UP>
br-f68c9df397fa UP 02:42:92:59:d5:6c <BROADCAST,MULTICAST,UP,LOWER_UP>
br-131ad989692b DOWN 02:42:84:4e:6e:12 <NO-CARRIER,BROADCAST,MULTICAST,UP>
br-194e7a613502 DOWN 02:42:61:b8:5d:7a <NO-CARRIER,BROADCAST,MULTICAST,UP>
br-2a67d8f8b954 DOWN 02:42:c2:d1:b4:e1 <NO-CARRIER,BROADCAST,MULTICAST,UP>
br-37692a4e723c UP 02:42:a9:7b:1f:3a <BROADCAST,MULTICAST,UP,LOWER_UP>
br-3f32a31d3339 UP 02:42:06:e1:4b:19 <BROADCAST,MULTICAST,UP,LOWER_UP>
br-499e90637a6b DOWN 02:42:3c:d7:50:ca <NO-CARRIER,BROADCAST,MULTICAST,UP>
br-552074ecc891 DOWN 02:42:f8:04:ed:b7 <NO-CARRIER,BROADCAST,MULTICAST,UP>
br-0e204ce773a5 DOWN 02:42:a5:2c:56:25 <NO-CARRIER,BROADCAST,MULTICAST,UP>
br-68d74d345015 DOWN 02:42:42:d7:7a:37 <NO-CARRIER,BROADCAST,MULTICAST,UP>
br-c41dfb61e164 DOWN 02:42:ee:61:a9:ae <NO-CARRIER,BROADCAST,MULTICAST,UP>
br-cf71a6f7b6d3 DOWN 02:42:52:85:a0:b7 <NO-CARRIER,BROADCAST,MULTICAST,UP>
br-f0c082f01e56 DOWN 02:42:d3:80:d0:bf <NO-CARRIER,BROADCAST,MULTICAST,UP>
br-639bfb1bea34 DOWN 02:42:2f:93:cc:d2 <NO-CARRIER,BROADCAST,MULTICAST,UP>
veth759ec1c@if26 UP 2e:8a:16:fd:f5:de <BROADCAST,MULTICAST,UP,LOWER_UP>
veth44148ca@if28 UP 62:b4:1f:13:bc:51 <BROADCAST,MULTICAST,UP,LOWER_UP>
vethc7f2d65@if30 UP 52:9e:00:cb:c7:46 <BROADCAST,MULTICAST,UP,LOWER_UP>
veth0067bf4@if32 UP 5e:6f:bb:a0:28:1c <BROADCAST,MULTICAST,UP,LOWER_UP>
veth443e622@if34 UP d2:97:46:de:79:91 <BROADCAST,MULTICAST,UP,LOWER_UP>
lo UNKNOWN 127.0.0.1/8 ::1/128
enp3s0 UP 192.168.0.102/24 2804:14c:6583:5e7f::1000/128 2804:14c:6583:5e7f:c496:f510:ca8c:79ce/64 fe80::9847:c342:d509:4024/64
br-9ca719aa01c7 DOWN 192.168.96.1/20
br-b97158ffcc3c DOWN 172.20.0.1/16
docker0 DOWN 172.17.0.1/16
br-55cb011b3e0d DOWN 192.168.160.1/20
br-777211ddb717 DOWN 172.26.0.1/16
br-a16997434552 UP 172.28.0.1/16 fe80::42:55ff:fe72:e0b8/64
br-bcf7ce342cb9 UP 172.22.0.1/16 fe80::42:f1ff:fef0:8e7b/64
br-d4e258cd683a DOWN 172.24.0.1/16
br-4b3e4deacee9 DOWN 192.168.48.1/20
br-f68c9df397fa UP 172.27.0.1/16 fe80::42:92ff:fe59:d56c/64
br-131ad989692b DOWN 172.23.0.1/16
br-194e7a613502 DOWN 192.168.80.1/20
br-2a67d8f8b954 DOWN 192.168.240.1/20
br-37692a4e723c UP 172.29.0.1/16 fe80::42:a9ff:fe7b:1f3a/64
br-3f32a31d3339 UP 172.31.0.1/16 fe80::42:6ff:fee1:4b19/64
br-499e90637a6b DOWN 172.18.0.1/16
br-552074ecc891 DOWN 172.19.0.1/16
br-0e204ce773a5 DOWN 172.30.0.1/16
br-68d74d345015 DOWN 192.168.16.1/20
br-c41dfb61e164 DOWN 192.168.0.1/20
br-cf71a6f7b6d3 DOWN 172.25.0.1/16
br-f0c082f01e56 DOWN 172.21.0.1/16
br-639bfb1bea34 DOWN 192.168.112.1/20
veth759ec1c@if26 UP fe80::2c8a:16ff:fefd:f5de/64
Lucas Andrade, [30.05.21 09:50]
veth44148ca@if28 UP fe80::60b4:1fff:fe13:bc51/64
vethc7f2d65@if30 UP fe80::509e:ff:fecb:c746/64
veth0067bf4@if32 UP fe80::5c6f:bbff:fea0:281c/64
veth443e622@if34 UP fe80::d097:46ff:fede:7991/64
default via 192.168.0.1 dev enp3s0 proto dhcp metric 100
172.17.0.0/16 dev docker0 proto kernel scope link src 172.17.0.1 linkdown
172.18.0.0/16 dev br-499e90637a6b proto kernel scope link src 172.18.0.1 linkdown
172.19.0.0/16 dev br-552074ecc891 proto kernel scope link src 172.19.0.1 linkdown
172.20.0.0/16 dev br-b97158ffcc3c proto kernel scope link src 172.20.0.1 linkdown
172.21.0.0/16 dev br-f0c082f01e56 proto kernel scope link src 172.21.0.1 linkdown
172.22.0.0/16 dev br-bcf7ce342cb9 proto kernel scope link src 172.22.0.1
172.23.0.0/16 dev br-131ad989692b proto kernel scope link src 172.23.0.1 linkdown
172.24.0.0/16 dev br-d4e258cd683a proto kernel scope link src 172.24.0.1 linkdown
172.25.0.0/16 dev br-cf71a6f7b6d3 proto kernel scope link src 172.25.0.1 linkdown
172.26.0.0/16 dev br-777211ddb717 proto kernel scope link src 172.26.0.1 linkdown
172.27.0.0/16 dev br-f68c9df397fa proto kernel scope link src 172.27.0.1
172.28.0.0/16 dev br-a16997434552 proto kernel scope link src 172.28.0.1
172.29.0.0/16 dev br-37692a4e723c proto kernel scope link src 172.29.0.1
172.30.0.0/16 dev br-0e204ce773a5 proto kernel scope link src 172.30.0.1 linkdown
172.31.0.0/16 dev br-3f32a31d3339 proto kernel scope link src 172.31.0.1
192.168.0.0/24 dev enp3s0 proto kernel scope link src 192.168.0.102 metric 100
192.168.0.0/20 dev br-c41dfb61e164 proto kernel scope link src 192.168.0.1 linkdown
192.168.16.0/20 dev br-68d74d345015 proto kernel scope link src 192.168.16.1 linkdown
192.168.48.0/20 dev br-4b3e4deacee9 proto kernel scope link src 192.168.48.1 linkdown
192.168.80.0/20 dev br-194e7a613502 proto kernel scope link src 192.168.80.1 linkdown
192.168.96.0/20 dev br-9ca719aa01c7 proto kernel scope link src 192.168.96.1 linkdown
192.168.112.0/20 dev br-639bfb1bea34 proto kernel scope link src 192.168.112.1 linkdown
192.168.160.0/20 dev br-55cb011b3e0d proto kernel scope link src 192.168.160.1 linkdown
192.168.240.0/20 dev br-2a67d8f8b954 proto kernel scope link src 192.168.240.1 linkdown
答案1
OP其實有一個很多網路設定：幾個 Docker 網路。
其中之一如下圖所示：
地址：
br-c41dfb61e164 DOWN 192.168.0.1/20
路線：
192.168.0.0/20 dev br-c41dfb61e164 proto kernel scope link src 192.168.0.1 linkdown
新增位址至主機：192.168.0.1/20。 Linux 遵循弱者主機型號，該地址始終可用（羅向上）無論狀態如何br-c41dfb61e164。
它與主機路由器（也稱為網關）設定的 DHCP 設定衝突，該路由器使用 192.168.0.1/24。 Linux 上的 DHCP 使用帶外方法（原始套接字）來工作，因此繞過任何網路「異常」：當 DHCP 工作時，它會設定：
default via 192.168.0.1 dev enp3s0 proto dhcp metric 100
當主機有自己的位址作為網關時，就好像它沒有使用任何網關一樣：對Internet 上任何位址的任何請求都會觸發ARP 請求，該請求將失敗，而不是透過路由器發送封包（這將是唯一的位址）應該使用正確的網路設定進行 ARP）。此外，這也可能隨機中斷使用該網路的其他設備，因為它也會應答對網關位址的 ARP 請求。
快速解決方法是停用並停止 Docker，如果沒有正確清理，則可能需要重新啟動，如下所示OP在評論中證實:
systemctl disable --now docker
（也可以選擇關聯systemctl mask docker.socket以避免任何「虛假」啟動）
長期修復與 Docker 設定有關，超出了本問題的範圍。這裡有兩個建議：
清理未使用的容器和相關網絡
變更 Docker 設置，以便新網路的分配更小（例如 /24），並且位於未使用的位址空間中，可能位於 10.0.0.0/8 中的某個位置，但請注意與某些 VPN 發生衝突。
可以從這個 SF Q/A 中取得範例：將 Docker 配置為不使用 172.17.0.0 範圍