Network Problems after upgrading to 22.04.1

After upgrading from 20.04 to 22.04.1, I have no network access either via ethernet or wifi.

I can bring both interfaces up via command line or gui and they show as connected and also pick up an ip address over dhcp.

However, I can't ping anything (by address) - not even the loopback address.

The firewall is disabled. The routing table matches one of my other machines which is working fine.

Any ideas to debug this one gratefully received!

Possibly related to Broken network configuration after upgrade to 22.04

Network Manager Status

● NetworkManager.service - Network Manager     Loaded: loaded (/lib/systemd/system/NetworkManager.service; enabled; vendor preset: enabled)     Active: active (running) since Wed 2022-08-17 18:30:16 BST; 1 day 19h ago       Docs: man:NetworkManager(8)   Main PID: 1582 (NetworkManager)      Tasks: 3 (limit: 16572)     Memory: 11.3M        CPU: 5.092s     CGroup: /system.slice/NetworkManager.service└─1582 /usr/sbin/NetworkManager --no-daemonAug 19 13:54:43 deepthought NetworkManager[1582]: <info>  [1660913683.8481] dhcp4 (enp34s0): activation: beginning transaction (timeout in 45 seconds)Aug 19 13:54:43 deepthought NetworkManager[1582]: <info>  [1660913683.8654] dhcp4 (enp34s0): state changed new lease, address=192.168.0.225Aug 19 13:54:43 deepthought NetworkManager[1582]: <info>  [1660913683.8679] device (enp34s0): state change: ip-config -> ip-check (reason 'none', sys-iface-state: 'managed')Aug 19 13:54:43 deepthought NetworkManager[1582]: <info>  [1660913683.9135] device (enp34s0): state change: ip-check -> secondaries (reason 'none', sys-iface-state: 'managed')Aug 19 13:54:43 deepthought NetworkManager[1582]: <info>  [1660913683.9140] device (enp34s0): state change: secondaries -> activated (reason 'none', sys-iface-state: 'managed')Aug 19 13:54:43 deepthought NetworkManager[1582]: <info>  [1660913683.9146] manager: NetworkManager state is now CONNECTED_LOCALAug 19 13:54:43 deepthought NetworkManager[1582]: <info>  [1660913683.9150] manager: NetworkManager state is now CONNECTED_SITEAug 19 13:54:43 deepthought NetworkManager[1582]: <info>  [1660913683.9151] policy: set 'netplan-enp34s0' (enp34s0) as default for IPv4 routing and DNSAug 19 13:54:43 deepthought NetworkManager[1582]: <info>  [1660913683.9158] device (enp34s0): Activation: successful, device activated.Aug 19 13:54:53 deepthought NetworkManager[1582]: <info>  [1660913693.3834] agent-manager: agent[438527325db3dfb9,:1.82/org.gnome.Shell.NetworkAgent/1000]: agent registered

resolved

systemd-resolved also looks unhappy although I'm way off being able to use names right now.

● systemd-resolved.service - Network Name Resolution     Loaded: loaded (/lib/systemd/system/systemd-resolved.service; enabled; vendor preset: enabled)     Active: active (running) since Wed 2022-08-17 18:30:15 BST; 1 day 19h ago       Docs: man:systemd-resolved.service(8)             man:org.freedesktop.resolve1(5)             https://www.freedesktop.org/wiki/Software/systemd/writing-network-configuration-managers             https://www.freedesktop.org/wiki/Software/systemd/writing-resolver-clients   Main PID: 1278 (systemd-resolve)     Status: "Processing requests..."      Tasks: 1 (limit: 16572)     Memory: 9.4M        CPU: 517ms     CGroup: /system.slice/systemd-resolved.service└─1278 /lib/systemd/systemd-resolvedAug 19 14:19:16 deepthought systemd-resolved[1278]: Using degraded feature set UDP instead of TCP for DNS server 192.168.0.2.Aug 19 14:19:26 deepthought systemd-resolved[1278]: Using degraded feature set TCP instead of UDP for DNS server 192.168.0.2.Aug 19 14:19:57 deepthought systemd-resolved[1278]: Using degraded feature set UDP instead of TCP for DNS server 192.168.0.2.Aug 19 14:20:08 deepthought systemd-resolved[1278]: Using degraded feature set TCP instead of UDP for DNS server 192.168.0.2.Aug 19 14:23:35 deepthought systemd-resolved[1278]: Using degraded feature set UDP instead of TCP for DNS server 192.168.0.2.Aug 19 14:23:45 deepthought systemd-resolved[1278]: Using degraded feature set TCP instead of UDP for DNS server 192.168.0.2.Aug 19 14:24:16 deepthought systemd-resolved[1278]: Using degraded feature set UDP instead of TCP for DNS server 192.168.0.2.Aug 19 14:24:26 deepthought systemd-resolved[1278]: Using degraded feature set TCP instead of UDP for DNS server 192.168.0.2.Aug 19 14:24:57 deepthought systemd-resolved[1278]: Using degraded feature set UDP instead of TCP for DNS server 192.168.0.2.Aug 19 14:25:08 deepthought systemd-resolved[1278]: Using degraded feature set TCP instead of UDP for DNS server 192.168.0.2.