我在南卡罗来纳州更新到了 Ubuntu 20.04，我的 NetGear N300 扩展器在 Ubuntu 20.04 启动时与 Spectrum 路由器配合使用。现在搬回费城，使用康卡斯特的新路由器。我可以在 Windows 启动时完美连接到扩展器，但在 Ubuntu 20.04 启动时出现问号，无法连接到任何网页。在 Ubuntu 中不起作用。这一定是 Ubuntu 20.04/Comcast 路由器/NetGear 组合问题，因为 Ubuntu 20.04/Spectrum 路由器/NetGear 和 Windows/Comcast 路由器/NetGear 都可以工作。
以下是系统日志的结尾：
Nov 1 12:34:56 coyote-HP-250-G5-Notebook-PC avahi-daemon[699]: Joining mDNS multicast group on interface wlo1.IPv6 with address 2601:48:4302:6dd0:f505:557f:35df:71c6.
Nov 1 12:34:56 coyote-HP-250-G5-Notebook-PC avahi-daemon[699]: Registering new address record for 2601:48:4302:6dd0:f505:557f:35df:71c6 on wlo1.*.
Nov 1 12:34:56 coyote-HP-250-G5-Notebook-PC avahi-daemon[699]: Withdrawing address record for fe80::c255:4ab6:e6a:3e97 on wlo1.
Nov 1 12:34:56 coyote-HP-250-G5-Notebook-PC whoopsie[1353]: [12:34:56] Cannot reach: https://daisy.ubuntu.com
Nov 1 12:34:56 coyote-HP-250-G5-Notebook-PC NetworkManager[3931]: <info> [1604252096.5951] dhcp6 (wlo1): option dhcp6_name_servers => '2001:558:feed::1 2001:558:feed::2'
Nov 1 12:34:56 coyote-HP-250-G5-Notebook-PC NetworkManager[3931]: <info> [1604252096.5951] dhcp6 (wlo1): option ip6_address => '2601:48:4302:6dd0::8777'
Nov 1 12:34:56 coyote-HP-250-G5-Notebook-PC NetworkManager[3931]: <info> [1604252096.5951] dhcp6 (wlo1): state changed unknown -> bound
Nov 1 12:34:56 coyote-HP-250-G5-Notebook-PC whoopsie[1353]: [12:34:56] Cannot reach: https://daisy.ubuntu.com
Nov 1 12:34:56 coyote-HP-250-G5-Notebook-PC avahi-daemon[699]: Registering new address record for 2601:48:4302:6dd0::8777 on wlo1.*.
Nov 1 12:34:57 coyote-HP-250-G5-Notebook-PC whoopsie[1353]: [12:34:57] Cannot reach: https://daisy.ubuntu.com
Nov 1 12:34:58 coyote-HP-250-G5-Notebook-PC NetworkManager[3931]: <info> [1604252098.2080] device (wlo1): state change: ip-config -> ip-check (reason 'none', sys-iface-state: 'managed')
Nov 1 12:34:58 coyote-HP-250-G5-Notebook-PC NetworkManager[3931]: <info> [1604252098.2106] device (wlo1): state change: ip-check -> secondaries (reason 'none', sys-iface-state: 'managed')
Nov 1 12:34:58 coyote-HP-250-G5-Notebook-PC NetworkManager[3931]: <info> [1604252098.2109] device (wlo1): state change: secondaries -> activated (reason 'none', sys-iface-state: 'managed')
Nov 1 12:34:58 coyote-HP-250-G5-Notebook-PC NetworkManager[3931]: <info> [1604252098.2114] manager: NetworkManager state is now CONNECTED_LOCAL
Nov 1 12:34:58 coyote-HP-250-G5-Notebook-PC NetworkManager[3931]: <info> [1604252098.2135] manager: NetworkManager state is now CONNECTED_SITE
Nov 1 12:34:58 coyote-HP-250-G5-Notebook-PC NetworkManager[3931]: <info> [1604252098.2136] policy: set 'MCBS1_EXT' (wlo1) as default for IPv6 routing and DNS
Nov 1 12:34:58 coyote-HP-250-G5-Notebook-PC NetworkManager[3931]: <info> [1604252098.2143] device (wlo1): Activation: successful, device activated.
Nov 1 12:34:58 coyote-HP-250-G5-Notebook-PC nm-dispatcher[5432]: postconf: fatal: open /etc/postfix/main.cf: No such file or directory
Nov 1 12:34:58 coyote-HP-250-G5-Notebook-PC avahi-daemon[699]: Registering new address record for 2601:48:4302:6dd0:e66b:cec5:3ae:1c70 on wlo1.*.
Nov 1 12:34:59 coyote-HP-250-G5-Notebook-PC whoopsie[1353]: [12:34:59] Cannot reach: https://daisy.ubuntu.com
Nov 1 12:34:59 coyote-HP-250-G5-Notebook-PC systemd-resolved[647]: Server returned error NXDOMAIN, mitigating potential DNS violation DVE-2018-0001, retrying transaction with reduced feature level UDP.
Nov 1 12:34:59 coyote-HP-250-G5-Notebook-PC whoopsie[1353]: [12:34:59] Cannot reach: https://daisy.ubuntu.com
Nov 1 12:35:01 coyote-HP-250-G5-Notebook-PC CRON[5441]: (root) CMD (command -v debian-sa1 > /dev/null && debian-sa1 1 1)