Netplan config with IPv4 and IPV6

Thystra

10/18/23, 3:31 PM

I am trying to update a server with IPv4 and IPv6 addresses to 22.04.1. I was trying to get netplan updated and it wanted routes, but I was having some trouble getting the config correct and lost network on the server. The netplan examples don't have much in the way of IPv6 examples and I've not found anything helpful while searching.

    network:
  version: 2
#  renderer: networkd
  ethernets:
    eth0:
      addresses:
        - xxx.xxx.xxx.xxx/18
        - aaaa:aaaa:aaa:aa::aaa:aaaa/64
      gateway4: 111.111.1.1
      gateway6: bbbb:bbbb:bbb:bb::b
      nameservers:
        addresses: 
#quad 9 DNS servers
          - 9.9.9.9
          - 149.112.112.112
          - 2620:fe::fe 
          - 2620:fe::9

2933

1 + 0

server

networking

netplan

Score:3

Ubuntu

dummyuser

10/18/23, 5:31 PM

A netplan file with ipv6 looks like

network:
  version: 2
  ethernets:
    enp2s0:
      critical: true
      dhcp-identifier: mac
      dhcp4: false
      addresses:
        - 192.168.1.20/26
        - 2001:0db8:100:2::20/64
      routes:
        - to: default    # defaut ipv4
          via: 192.168.1.1
        - to: "::/0"      # defaut ipv6
          via: "2001:0db8:100:2::1"
          on-link: true

  nameservers:
    addresses:
    - 192.168.1.1
    - 2001:0db8:100:2::1

please note gateway4 and gateway6 are deprecated. Use regulary routes as shown.

+ 5

Thystra

10/18/23, 7:47 PM

I had to edit the nameserver section, and then I got this warning: ** (generate:4248): WARNING **: 15:43:42.578: Problem encountered while validating default route consistency.Please set up multiple routing tables and use `routing-policy` instead. Error: Conflicting default route declarations for IPv4 (table: main, metric: default), first declared in enp2s0 but also in eth0

dummyuser

10/18/23, 8:01 PM

You may need to adopt some settings like interface names to your needs. I posted a sample, not a full solution for you.

Thystra

10/18/23, 8:05 PM

I think I found part of the issue - I had setup a strongswan VPN server on the box as well, and it has another IP address on eth0, which is probably causing the conflict

dummyuser

10/18/23, 8:32 PM

perfect, if you want to get support, it makes sense to provide as much info as possible.

Thystra

10/18/23, 11:42 PM

I didn't catch it until I had logged back in on another terminal and it displayed the IP address.

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EN: Netplan config with IPv4 and IPV6

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