Assign a link-local address to Linux and use DNS-SD / SSDP

For devices that automatically come up with a link local address (IPv4) in an environment without DHCP How to use APIPA on Ubuntu / Debian and how to discover for automatic configuration

Preparation

Installation of required packages

If you just use APIPA, you can achieve your goal with avahi-autoipd.

sudo apt-get install -y avahi-autoipd

As related tools, avahi-daemon and avahi-utils, as there are cases where names and services are resolved. In addition, if you want to detect with SSDP, add gupnp-tools.

sudo apt-get install -y avahi-utils gupnp-tools

Setting

If you want to use it with eth2, add the following to / etc / network / interfaces. With this setting, APIPA is applied to the eth2: avahi interface.

/etc/network/interfaces

auto eth2
iface eth2 inet manual
  up /usr/sbin/avahi-autoipd -D --force-bind eth2
  down /usr/sbin/avahi-autoipd -k eth2

Use

Just up the interface

sudo ifup eth2

Verification

root@buster:~# ip -4 a
...
4: eth2: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP group default qlen 1000
    inet 169.254.5.253/16 brd 169.254.255.255 scope link eth2:avahi
       valid_lft forever preferred_lft forever

Resolve IPs for things you know the name of

If you know the name, mDNS resolves the name in the .local domain. For example, if you want to resolve a machine called fs, ping fs.local

Try to display the service list with DNS-SD

avahi-browse -al

When you run it, it looks like this

root@buster:~# avahi-browse -al
+   eth1 IPv4 amzn.dmgr:xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx:xxxxxxxxxx:##### _amzn-wplay._tcp     local
+   eth1 IPv4 fs - SSH                                      SSH Remote Terminal  local
+   eth1 IPv4 fs - SMB/CIFS                                 Microsoft Windows Network local
+   eth1 IPv4 fs - NFS - home                               Network File System  local
+   eth1 IPv4 Google-Home-xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx  _googlecast._tcp     local
+   eth1 IPv4 Chromecast-xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx   _googlecast._tcp     local

If you add r to the option, it will resolve and display even the IP and port.

Try to display the device list with SSDP

Specify the interface and use gssdp-discover

gssdp-discover -i eth2:avahi

root@buster:~# gssdp-discover -i eth2:avahi --timeout=3
Using network interface eth2:avahi
Scanning for all resources
Showing "available" messages
resource available
  USN:      uuid:1a78e91b-d86d-11ea-8157-080027e8f737::upnp:rootdevice
  Location: http://169.254.86.237:1900/ddd.xml