I have a Fedora 25 machine. Sometimes I misspell a hostname for SSH. Then I do
ssh examle.com. For some reason, I then get connected to my machine (
localhost) via SSH. I notice this because if there are
SSH_ variables in the environment, my shell prompt shows that.
Right now at home, I get a clean hostname resolution error. What could be the cause of this on occasion? Some local DNS server just resolving everything it does not know to
StrictHostKeyChecking no host juqueen hostname juqueen.fz-juelich.de user hbn28e controlpath ~/.ssh/controlmasters/%r@%h:%p controlmaster auto controlpersist 15m host judac hostname judac.fz-juelich.de user hbn28e controlpath ~/.ssh/controlmasters/%r@%h:%p controlmaster auto controlpersist 15m host martin-ueding.de hostname martin-ueding.de user ssh-444717-mu StrictHostKeyChecking yes host hiskp hostname plato.itkp.uni-bonn.de user ueding host chaos hostname chaos.stw-bonn.de user mu host gateway.cb.uni-bonn.de ForwardAgent yes hostname gateway.cb.uni-bonn.de user ueding checkhostip yes controlpath ~/.ssh/controlmasters/%r@%h:%p controlmaster auto controlpersist 15m host qbig ForwardAgent yes #hostname gateway.cb.uni-bonn.de ProxyCommand ssh gateway.cb.uni-bonn.de "nc qbig %p" user ueding checkhostip yes controlpath ~/.ssh/controlmasters/%r@%h:%p controlmaster auto controlpersist 15m host gsp.fz-juelich.de hostname gsp.fz-juelich.de identityfile ~/.ssh/id_gsp_owncloud host martin-welsh hostname martin-welsh.fritz.box host martin-shire hostname martin-shire.fritz.box host martin-friese hostname martin-friese.fritz.box #hostname 192.168.188.71 host root@martin-welsh user root hostname martin-welsh.local host martin-criollo hostname 192.168.188.21 user shell port 2222 host martin-falabella hostname martin-falabella.fritz.box port 2222 host cip hostname cip-pool.physik.uni-bonn.de user s6mauedi
At home, I have an AVM FRITZ!Box router. That does some DNS magic and lets you resolve names in the local network. So I can do
ssh martin-friese.fritz.box from another computer and get a connection to the laptop. This nicely works without any Avahi/Zeroconf/Bonjour stuff and therefore also supports Windows and Android right away. The address http://fritz.box gets resolved to the router's web interface (
At the university, my computer still has the hostname
martin-friese.fritz.box. Perhaps this got baked into my Fedora installation a little too deep. I guess I should rather have
martin-friese and let the FRITZ!Box DNS bake in the
.fritz.box when I am at home.
When I now try to resolve a non-existing hostname, I get this:
$ host this-does-not-exist this-does-not-exist.fritz.box has address 127.0.53.53 this-does-not-exist.fritz.box mail is handled by 10 your-dns-needs-immediate-attention.box.
An internet search on
your-dns-needs-immediate-attention tells me that the
.box TLD is now a valid domain and that therefore there is a clash of my DNS with the global DNS.
The output of
dig does not really help me.
$ dig this-does-not-exist ; <<>> DiG 9.10.4-P5-RedHat-9.10.4-4.P5.fc25 <<>> this-does-not-exist ;; global options: +cmd ;; Got answer: ;; ->>HEADER<<- opcode: QUERY, status: NXDOMAIN, id: 10457 ;; flags: qr rd ra ad; QUERY: 1, ANSWER: 0, AUTHORITY: 1, ADDITIONAL: 1 ;; OPT PSEUDOSECTION: ; EDNS: version: 0, flags:; udp: 4096 ;; QUESTION SECTION: ;this-does-not-exist. IN A ;; AUTHORITY SECTION: . 10800 IN SOA a.root-servers.net. nstld.verisign-grs.com. 2017013000 1800 900 604800 86400 ;; Query time: 13 msec ;; SERVER: 22.214.171.124#53(126.96.36.199) ;; WHEN: Mo Jan 30 16:51:54 CET 2017 ;; MSG SIZE rcvd: 123
So I guess I just need to change my hostname to
martin-friese without the
.fritz.box? Or should I change it to
friese.martin-ueding.de, I own the domain but the registrar does not know anything about my laptop.