Comment 0 for bug 1701097

cloud-init trunk and xenial, yakkety, zesty and artful all fail

A network config with a ipv6 gateway route like:

subnets:
  - type: static
    address: 2001:4800:78ff:1b:be76:4eff:fe06:96b3
    netmask: 'ffff:ffff:ffff:ffff::'
    routes:
      - gateway: 2001:4800:78ff:1b::1
        netmask: '::'
        network: '::'

For eni rendering, this should create a post-up/post-down route command that generates a default ipv6 route entry, like this:

    post-up route add -A inet6 default gw 2001:4800:78ff:1b::1 || true
    pre-down route del -A inet6 default gw 2001:4800:78ff:1b::1 || true

However, what is currently generated is this:

    post-up route add -net :: netmask :: gw 2001:4800:78ff:1b::1 || true
    pre-down route del -net :: netmask :: gw 2001:4800:78ff:1b::1 || true

That does not install the route correctly as a default gateway route.

This is fallout from commit d00da2d5b0d45db5670622a66d833d2abb907388
net: normalize data in network_state object

This commit removed ipv6 route 'netmask' values, and converted them to
prefix length values, but failed to update the eni renderer's check for
ipv6 default gateway.