Well, there's your problem right there! The host 'caddis' doesn't have the ip address you think it should. This is partly due to your Resistance To Sensible Advice™.
Instead of using an /etc/hosts to locally and brittlely point at a static IP address, you should rely on DNS and DHCP. You can tell your DHCP server to always give the same IP address to caddis's eth0 interface. And you can tell DNS to return that IP address when it is queried. If your DHCP/DNS server is the same software (e.g. dnsmasq), the configuration is super easy. Going caddis --> salmo works because salmo doesn't care what ip address caddis has. Caddis has the right ip address for salmo. However, when salmo tries to connect to caddis, it tries 192.168.55.2 (from /etc/hosts) and NOTHING LIVES THERE, SO IT FAILS. Caddis ignores it, because .2 isn't one of its addresses. Caddis is getting its IP addresses from DHCP, which is honestly the SENSIBLE thing for it to do. It is a laptop. It moves around between different networks, having a static IP configuration will make it not work when you take it somewhere else. The SENSIBLE thing to do (as I said above) is to have the local DHCP server offer the expected ip address when caddis asks for one. That way, caddis works wherever you take it. And when it is connected to the network salmo is on, it gets an ip address that other hosts expect or can resolve with network wide DNS. As a secondary problem, having two interfaces (wlan0 and eth0) on the same network can lead to non-workingness, so yeah, you should turn off wifi if you are connected to ethernet too. On Thu, Dec 11, 2025 at 8:39 AM Rich Shepard <[email protected]> wrote: > > On Wed, 10 Dec 2025, Russell Senior wrote: > > > ( hostname && ip a && ping -c1 salmo && ip n ) > /tmp/caddis-to-salmo.txt > > caddis.appl-ecosys.com > 1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN group > default qlen 1000 > link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00 > inet 127.0.0.1/8 scope host lo > valid_lft forever preferred_lft forever > inet6 ::1/128 scope host > valid_lft forever preferred_lft forever > 2: wlan0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc mq state UP group > default qlen 1000 > link/ether a4:4e:31:a3:05:58 brd ff:ff:ff:ff:ff:ff > inet 192.168.55.111/24 brd 192.168.55.255 scope global dynamic > noprefixroute wlan0 ^^^^^^^^^^^^^^ NOT 192.168.55.2 > valid_lft 85900sec preferred_lft 85900sec > inet6 fe80::5747:a646:5cd8:a346/64 scope link noprefixroute > valid_lft forever preferred_lft forever > 3: eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP > group default qlen 1000 > link/ether 28:d2:44:2e:b4:62 brd ff:ff:ff:ff:ff:ff > inet 192.168.55.112/24 brd 192.168.55.255 scope global dynamic > noprefixroute eth0 ^^^^^^^^^^^^^^^ NOT 192.168.55.2 > valid_lft 85899sec preferred_lft 85899sec > inet6 fe80::73b6:7e97:9b2c:1f06/64 scope link noprefixroute > valid_lft forever preferred_lft forever > PING salmo.appl-ecosys.com (192.168.55.1) 56(84) bytes of data. > 64 bytes from salmo.appl-ecosys.com (192.168.55.1): icmp_seq=1 ttl=64 > time=0.830 ms > > --- salmo.appl-ecosys.com ping statistics --- > 1 packets transmitted, 1 received, 0% packet loss, time 0ms > rtt min/avg/max/mdev = 0.830/0.830/0.830/0.000 ms > 192.168.55.4 dev eth0 lladdr 74:83:c2:49:2b:61 STALE > 192.168.55.1 dev eth0 lladdr 0c:9d:92:83:6e:27 REACHABLE > fe80::218:aff:fe36:6a56 dev wlan0 lladdr 00:18:0a:36:6a:56 router STALE > fe80::218:aff:fe36:6a56 dev eth0 lladdr 00:18:0a:36:6a:56 router STALE > > Rich
