I changed the ip in the two yaml and put them to $rpi3B+/etc/netplan/, reboot, but the ipv6 doesn't work, only ipv4 works. BTW, you said you run wget and play youtube all on the rpi3B+, right?
This is the log on my rpi3B+: ubuntu@ubuntu:~$ ifconfig br0: flags=4163<UP,BROADCAST,RUNNING,MULTICAST> mtu 1500 inet 192.168.2.4 netmask 255.255.255.0 broadcast 192.168.2.255 inet6 fe80::7c3a:7cff:fe69:3425 prefixlen 64 scopeid 0x20<link> inet6 2001:470:35:3b1::2 prefixlen 64 scopeid 0x0<global> ether 7e:3a:7c:69:34:25 txqueuelen 1000 (Ethernet) RX packets 305 bytes 78562 (78.5 KB) RX errors 0 dropped 8 overruns 0 frame 0 TX packets 137 bytes 14821 (14.8 KB) TX errors 0 dropped 0 overruns 0 carrier 0 collisions 0 eth0: flags=4163<UP,BROADCAST,RUNNING,MULTICAST> mtu 1500 ether b8:27:eb:ce:ca:4c txqueuelen 1000 (Ethernet) RX packets 318 bytes 83612 (83.6 KB) RX errors 0 dropped 0 overruns 0 frame 0 TX packets 137 bytes 14821 (14.8 KB) TX errors 0 dropped 0 overruns 0 carrier 0 collisions 0 he-ipv6: flags=209<UP,POINTOPOINT,RUNNING,NOARP> mtu 1480 inet6 fe80::c0a8:204 prefixlen 64 scopeid 0x20<link> inet6 2001:470:35:3b1::1 prefixlen 64 scopeid 0x0<global> sit txqueuelen 1000 (IPv6-in-IPv4) RX packets 0 bytes 0 (0.0 B) RX errors 0 dropped 0 overruns 0 frame 0 TX packets 77 bytes 7128 (7.1 KB) TX errors 22 dropped 0 overruns 0 carrier 22 collisions 0 lo: flags=73<UP,LOOPBACK,RUNNING> mtu 65536 inet 127.0.0.1 netmask 255.0.0.0 inet6 ::1 prefixlen 128 scopeid 0x10<host> loop txqueuelen 1000 (Local Loopback) RX packets 807 bytes 61288 (61.2 KB) RX errors 0 dropped 0 overruns 0 frame 0 TX packets 807 bytes 61288 (61.2 KB) TX errors 0 dropped 0 overruns 0 carrier 0 collisions 0 ubuntu@ubuntu:~$ wget http://ftp.antik.sk/ubuntu-releases/eoan/ubuntu-19.10-live-server-amd64.iso --2020-02-24 09:38:24-- http://ftp.antik.sk/ubuntu-releases/eoan/ubuntu-19.10-live-server-amd64.iso Resolving ftp.antik.sk (ftp.antik.sk)... 2a02:130:9900:30::12, 88.212.10.12 Connecting to ftp.antik.sk (ftp.antik.sk)|2a02:130:9900:30::12|:80... failed: Connection timed out. Connecting to ftp.antik.sk (ftp.antik.sk)|88.212.10.12|:80... connected. HTTP request sent, awaiting response... 200 OK Length: 883949568 (843M) [application/x-iso9660-image] Saving to: ��‘ubuntu-19.10-live-server-amd64.iso��’ 9.10-live-server-am 0%[ ] 2.51K --.-KB/s eta 262d ^C -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1861936 Title: Raspberry Pi 3 network dies shortly after a burst of SD card IO and network load ((lan78xx): transmit queue 0 timed out) To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux-raspi2/+bug/1861936/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs