I have a project where I would like to connect two project boards together with an Ethernet cable.  No router, no hub, just two boards with a patch of cat5 between them.  In order to make this work I need to get a Link-local IPv4 address on each (RFC 3927).  I believe this is done with avahi, but I'm unsure if avahi is simply name resolution or if it performs the link-local address allocation as well.

 

Anyway here's what I've tried:

sudo apt-get install avahi-daemon avahi-discover libnss-mdns
# sudo reboot -r now
# systemctl script on reboot to log IP to file with `hostname -I`

What I find is that when I'm hooked up to my router `hostname -I` reports what I'd expect from my DHCP server, but when I hook up board-to-board or board-to-laptop, all I get is an IPv6 address (no IPv4) and moreover the IPv6 address I do get does not reply to pings.

 

Here's my config:

• Odroid-C1+
• Armbian_5.25_Odroidc1_Debian_jessie_default_3.10.104.7z
• Apt/Got : avahi-daemon, avahi-discover, libnss-mdns

 

As a final thought, I don't have to use Jessie.  Xenial or Desktop would be fine as well.  At this point I'm just curious what else is needed to make it work.

 

Any thoughts?

networking is networking.

you should use a crossover cable and set a static IP on each device..NO GATEWAY, Just the IP and subnet

Quote

you should use a crossover cable and set a static IP on each device..NO GATEWAY, Just the IP and subnet

Yep, that works great... got that working straight off the bat.  Just seams like Link-local addressing should be possible.

 

Just curious how to make it happen.

OK... figured it out

apt-get install avahi-autoip winbind libnss-winbind

then edit /etc/samba/smb.conf

dns proxy = yes

then add `wins` /etc/nsswitch.conf

hosts:	files wins myhostname mdns4_minimal [NOTFOUND=return] dns

Now when the SoC comes up, it is easy to find with netbios without having to nmap 65,000 address (replace hostname with 'raspberrypi' or 'odroidc1' or whatever the board name is.

nbtstat -a hostname
nbtstat -c
arp -a

This should be enough to get me started.  It pulls in a lot more software than needed, but it does meet my needs.

 

PS.. admins, feel free to change the subject from '[REQ]' to '[SOLVED]', though this one easily falls into RTFM.

Found some more information that may be missing... LLMNR (RFC 4795).  Here's the config I have right now.

apt-get install avahi-autoip winbind libnss-winbind
"dns proxy = yes" => /etc/samba/smb.conf
"hosts:	files wins ... dns" => /etc/nsswitch.conf

and this gets me most of what I need, but with the above config, I can only find the SoC server from Windows using NetBios utilities.  Conventional TCP/IP resolutions don't work.

 

Looks like there is an LLMNR option in resolved.conf.  So perhaps adding this will allow the SoC server to broadcast its information better...

"LLMNR=yes" => /etc/*/resolved.conf

I'll update if it works.