我最近升级到了 19.10。有时，我发现 DNS 无法正确解析，例如在 Firefox 或 Thunderbird 中。在另一个选项卡中尝试相同的请求将产生相同的结果。在私人选项卡中立即尝试相同的 URL（而其他选项卡仍处于挂起状态），可以正常解析该站点。其他 URL 仍可顺利解析，而其他 URL 仍处于挂起状态。
几秒钟后，影响消失，所有 URL 和所有协议都恢复正常。
目前，这种情况似乎每个工作日都会随机发生约 10-15 次。IMAP 连接或 SSH 连接也会发生这种情况。
使用 wireshark，当问题发生时，我看到很多 ICMP 目标无法到达我的路由器。我最近还将路由器更新到其最新固件（华硕 RT-AC68U）。日志目前没有显示任何内容。连接通过 Cat6/以太网进行。
我的 DNS 解析器正在使用符号链接的 resolv.conf 到 /run/systemd/resolve/stub-resolv.conf：
nameserver 127.0.0.53
options edns0
编辑：我当前的 /etc/systemd/resolved.conf
# This file is part of systemd.
#
# systemd is free software; you can redistribute it and/or modify it
# under the terms of the GNU Lesser General Public License as published by
# the Free Software Foundation; either version 2.1 of the License, or
# (at your option) any later version.
#
# Entries in this file show the compile time defaults.
# You can change settings by editing this file.
# Defaults can be restored by simply deleting this file.
#
# See resolved.conf(5) for details
[Resolve]
#DNS=
#FallbackDNS=
#Domains=
#LLMNR=no
#MulticastDNS=no
#DNSSEC=no
#DNSOverTLS=no
#Cache=yes
#DNSStubListener=yes
#ReadEtcHosts=yes
ping -c 5 8.8.8.8
PING 8.8.8.8 (8.8.8.8) 56(84) bytes of data.
64 bytes from 8.8.8.8: icmp_seq=1 ttl=55 time=1.29 ms
64 bytes from 8.8.8.8: icmp_seq=2 ttl=55 time=1.05 ms
64 bytes from 8.8.8.8: icmp_seq=3 ttl=55 time=1.11 ms
64 bytes from 8.8.8.8: icmp_seq=4 ttl=55 time=1.12 ms
64 bytes from 8.8.8.8: icmp_seq=5 ttl=55 time=1.12 ms
--- 8.8.8.8 ping statistics ---
5 packets transmitted, 5 received, 0% packet loss, time 4004ms
rtt min/avg/max/mdev = 1.046/1.136/1.288/0.080 ms
www.ebay.com is an alias for slot9428.ebay.com.edgekey.net.
slot9428.ebay.com.edgekey.net is an alias for e9428.b.akamaiedge.net.
e9428.b.akamaiedge.net has address 23.211.5.229