After some more research it seems that the issue is described at https://github.com/hashicorp/nomad/issues/3675
mad[21769]: 2020-10-16T20:27:33.812+0200 [DEBUG] client.fingerprint_mgr: fingerprinting periodically: fingerprinter=consul period=15s
Oct 16 20:27:40 node-1 nomad[21769]: 2020-10-16T20:27:33.814+0200 [DEBUG] client.fingerprint_mgr.cpu: detected cpu frequency: MHz=1200
Oct 16 20:27:40 node-1 nomad[21769]: 2020-10-16T20:27:33.814+0200 [DEBUG] client.fingerprint_mgr.cpu: detected core count: cores=4
Oct 16 20:27:40 node-1 nomad[21769]: 2020-10-16T20:27:34.114+0200 [DEBUG] client.fingerprint_mgr.network: link speed detected: interface=eth0 mbits=100
Oct 16 20:27:40 node-1 nomad[21769]: 2020-10-16T20:27:34.114+0200 [DEBUG] client.fingerprint_mgr.network: detected interface IP: interface=eth0 IP=192.168.178.201
Oct 16 20:27:40 node-1 nomad[21769]: 2020-10-16T20:27:34.114+0200 [DEBUG] client.fingerprint_mgr.network: detected interface IP: interface=eth0 IP=192.168.178.222
Nomad seems to detect both interfaces both not that one is an alias:
eth0: flags=4163<UP,BROADCAST,RUNNING,MULTICAST> mtu 1500
inet 192.168.178.201 netmask 255.255.255.0 broadcast 192.168.178.255
inet6 fe80::ffb8:350b:8e47:201a prefixlen 64 scopeid 0x20<link>
ether b8:27:eb:a9:25:bd txqueuelen 1000 (Ethernet)
RX packets 1220521461 bytes 139514618021 (129.9 GiB)
RX errors 0 dropped 8 overruns 0 frame 0
TX packets 1420222591 bytes 191440300641 (178.2 GiB)
TX errors 0 dropped 0 overruns 0 carrier 0 collisions 0
eth0:1234: flags=4163<UP,BROADCAST,RUNNING,MULTICAST> mtu 1500
inet 192.168.178.222 netmask 255.255.255.0 broadcast 192.168.178.255
ether b8:27:eb:a9:25:bd txqueuelen 1000 (Ethernet)