I guess this is hardware-independent, so I post here. Looking for ways to disable IPv6 I found 3 ways to achieve this on Linux, none of them really working for armbian debian build.
 

1. /etc/sysctl.conf:

net.ipv6.conf.all.disable_ipv6 = 1
net.ipv6.conf.default.disable_ipv6 = 1
net.ipv6.conf.lo.disable_ipv6 = 1

this disables the network interfaces to use IPv6, not IPv6 itself. This method is also known to cause trouble e.g with X-Forwarding via SSH and Postfix server.
netstat still lists IPv6 entries

 

2.  /etc/default/grub (GRUB tells the kernel not to load IPv6)

This does not exist in armbian, I guess it is simply not using GRUB

 

3. /etc/modprobe.d/aliases

change

alias net-pf-10 ipv6

to

alias net-pf-10 off

 

Some people suggest to additionally add

alias ipv6 off

 

I'm not so sure what this is actually doing. It does probably set an alias so that some other instance that starts net-pf-10 does not start ipv6 but instead "off" which is not defined so nothing is started?!

However this file does not exist in armbian as well

 

So how can I disable IPv6 on armbian?

 

for me, ARMBIAN 5.31 stable Ubuntu 16.04.3 LTS 3.4.113-sun8i 

 

adding "net.ipv6.conf.all.disable_ipv6=1" in "/etc/sysctl.conf" did the trick

second thought, i think you have trim the space in between " = "