Score:1

Where can I find the default IPv6 config location on Ubuntu 20.04 Server?

in flag

I just installed an Ubuntu Server 20.04 via the installation manager. I defined a static IPv4 address and left Ipv6 untouched.

After starting the machine, I can see my static Ipv4 and also multiple Ipv6 addresses (link local and public).

I can see that the config for the static Ipv4 is done in /etc/netplan/00-installer-config.yaml however, I cannot see the Ipv6 configuration (which should be SLAAC).

According to the Netplan docs, it only overrides configs defined but leaves others untouched, which means I did not configure Ipv6 during installation. Therefore, there is no entry for Ipv6 (in netplan). However, where is IPv6 default config defined?

I also checked /etc/network/interfaces, but this file is completely empty.

Can someone tell me where the default IPv6 config can be found?

Thanks

in flag
Ok so i figured out that netplan sets the config for netwrokd. So i checked the relevant folder:
in flag
i found a file called "10-netplan-eth0.network" in /run/systemd/netwrok which has the line "LinkLocalAddressing=ipv6" however nothing about SLAAC. So my assumption is netplan generates the file for networkd and places it in /run however i still don't get where the SLAAC configuration originates from. None of the networkd or the netplan config files point out that ipv6 SLAAC is enabled. Does someone know from where the default Ipv6 config is located ?
Score:0
in flag

The IPv6 SLAAC addressing are defaults compiled into the Kernel.

If you review /etc/sysctl.conf you won't see them, but if you execute:

sudo sysctl -a | grep ipv6 | grep -w "= 1"

you'll see what's enabled by default.

I was initially scratching my head when I saw nothing in Netplan to explain where the SLAAC addressing was happening. That's where it lives...

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