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I've got a Ubuntu Linux box that has two IPv4 addresses and an IPv6 address. This is my current /etc/network/interfaces:

auto lo
iface lo inet loopback

auto eth0 eth0:0

iface eth0 inet static

iface eth0:0 inet static

I want to add the IPv6 address (2600:3c03::c0a8/128, a few octets removed) to eth0 so that it's autoconfigured. However, adding a sub-interface eth0:1 and entering iface eth0:1 inet6 autoconf didn't work:

/etc/network/interfaces:15: unknown method
ifdown: couldn't read interfaces file "/etc/network/interfaces"

Is there a way that I can auto-configure IPv6 and statically configure IPv4 on the same interface?

*The .512 is just for obfuscation; the IPv4 IPs are fine.

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up vote 1 down vote accepted

I solved the problem. Apparently, UFW (my front-end for iptables) was not set to be configured for IPv6. Setting IPV6=no to IPV6=yes in /etc/default/ufw solved the problem and allowed IPv6 autoconfiguration.

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