In the SYS and KS dedicated servers, if we install Ubuntu from the OVH provided image and take a look at the NetPlan config file /etc/netplan/50-cloud-init.yaml as well as the default routes for IPv4 and IPv6, there are a large number of additional IPv6 routes configured.
Can someone tell me what all these additional IPv6 routes are for? They seem to vary slightly from server to server. I am wondering of they are really needed? Ideally I would like to remove the non-default routes if they are not needed so that I can simplify our automated installation scripts.
For example:
network:
version: 2
ethernets:
eno1:
accept-ra: false
addresses:
- 2001:41d0:2:9434::1/56
dhcp4: true
match:
macaddress: 0c:c4:7a:a8:95:e0
nameservers:
addresses:
- 2001:41d0:3:163::1
routes:
- to: default
via: 2001:41d0:2:94ff:ff:ff:ff:ff
- to: 2001:41d0:2:9440::/58
via: 2001:41d0:2:94ff:ff:ff:ff:ff
- to: 2001:41d0:2:9480::/58
via: 2001:41d0:2:94ff:ff:ff:ff:ff
- to: 2001:41d0:2:9400::/59
via: 2001:41d0:2:94ff:ff:ff:ff:ff
- to: 2001:41d0:2:94c0::/59
via: 2001:41d0:2:94ff:ff:ff:ff:ff
- to: 2001:41d0:2:9420::/60
via: 2001:41d0:2:94ff:ff:ff:ff:ff
- to: 2001:41d0:2:94e0::/60
via: 2001:41d0:2:94ff:ff:ff:ff:ff
- to: 2001:41d0:2:9438::/61
via: 2001:41d0:2:94ff:ff:ff:ff:ff
- to: 2001:41d0:2:94f0::/61
via: 2001:41d0:2:94ff:ff:ff:ff:ff
- to: 2001:41d0:2:9430::/62
via: 2001:41d0:2:94ff:ff:ff:ff:ff
- to: 2001:41d0:2:94f8::/62
via: 2001:41d0:2:94ff:ff:ff:ff:ff
- to: 2001:41d0:2:9436::/63
via: 2001:41d0:2:94ff:ff:ff:ff:ff
- to: 2001:41d0:2:94fc::/63
via: 2001:41d0:2:94ff:ff:ff:ff:ff
- to: 2001:41d0:2:9435::/64
via: 2001:41d0:2:94ff:ff:ff:ff:ff
- to: 2001:41d0:2:94fe::/64
via: 2001:41d0:2:94ff:ff:ff:ff:ff
- to: 2001:41d0:2:9434:8000::/65
via: 2001:41d0:2:94ff:ff:ff:ff:ff
- to: 2001:41d0:2:94ff:8000::/65
via: 2001:41d0:2:94ff:ff:ff:ff:ff
- to: 2001:41d0:2:9434:4000::/66
via: 2001:41d0:2:94ff:ff:ff:ff:ff
- to: 2001:41d0:2:94ff:4000::/66
via: 2001:41d0:2:94ff:ff:ff:ff:ff
- to: 2001:41d0:2:9434:2000::/67
via: 2001:41d0:2:94ff:ff:ff:ff:ff
- to: 2001:41d0:2:94ff:2000::/67
via: 2001:41d0:2:94ff:ff:ff:ff:ff
- to: 2001:41d0:2:9434:1000::/68
via: 2001:41d0:2:94ff:ff:ff:ff:ff
- to: 2001:41d0:2:94ff:1000::/68
via: 2001:41d0:2:94ff:ff:ff:ff:ff
- to: 2001:41d0:2:9434:800::/69
via: 2001:41d0:2:94ff:ff:ff:ff:ff
- to: 2001:41d0:2:94ff:800::/69
via: 2001:41d0:2:94ff:ff:ff:ff:ff
- to: 2001:41d0:2:9434:400::/70
via: 2001:41d0:2:94ff:ff:ff:ff:ff
- to: 2001:41d0:2:94ff:400::/70
via: 2001:41d0:2:94ff:ff:ff:ff:ff
- to: 2001:41d0:2:9434:200::/71
via: 2001:41d0:2:94ff:ff:ff:ff:ff
- to: 2001:41d0:2:94ff:200::/71
via: 2001:41d0:2:94ff:ff:ff:ff:ff
- to: 2001:41d0:2:9434:100::/72
via: 2001:41d0:2:94ff:ff:ff:ff:ff
- to: 2001:41d0:2:94ff:100::/72
via: 2001:41d0:2:94ff:ff:ff:ff:ff
- to: 2001:41d0:2:9434:80::/73
via: 2001:41d0:2:94ff:ff:ff:ff:ff
- to: 2001:41d0:2:94ff::/73
via: 2001:41d0:2:94ff:ff:ff:ff:ff
- to: 2001:41d0:2:9434:40::/74
via: 2001:41d0:2:94ff:ff:ff:ff:ff
- to: 2001:41d0:2:94ff:80::/74
via: 2001:41d0:2:94ff:ff:ff:ff:ff
- to: 2001:41d0:2:9434:20::/75
via: 2001:41d0:2:94ff:ff:ff:ff:ff
- to: 2001:41d0:2:94ff:c0::/75
via: 2001:41d0:2:94ff:ff:ff:ff:ff
- to: 2001:41d0:2:9434:10::/76
via: 2001:41d0:2:94ff:ff:ff:ff:ff
- to: 2001:41d0:2:94ff:e0::/76
via: 2001:41d0:2:94ff:ff:ff:ff:ff
- to: 2001:41d0:2:9434:8::/77
via: 2001:41d0:2:94ff:ff:ff:ff:ff
- to: 2001:41d0:2:94ff:f0::/77
via: 2001:41d0:2:94ff:ff:ff:ff:ff
- to: 2001:41d0:2:9434:4::/78
via: 2001:41d0:2:94ff:ff:ff:ff:ff
- to: 2001:41d0:2:94ff:f8::/78
via: 2001:41d0:2:94ff:ff:ff:ff:ff
- to: 2001:41d0:2:9434:2::/79
via: 2001:41d0:2:94ff:ff:ff:ff:ff
- to: 2001:41d0:2:94ff:fc::/79
via: 2001:41d0:2:94ff:ff:ff:ff:ff
- to: 2001:41d0:2:9434:1::/80
via: 2001:41d0:2:94ff:ff:ff:ff:ff
- to: 2001:41d0:2:94ff:fe::/80
via: 2001:41d0:2:94ff:ff:ff:ff:ff
- to: 2001:41d0:2:9434:0:8000::/81
via: 2001:41d0:2:94ff:ff:ff:ff:ff
- to: 2001:41d0:2:94ff:ff:8000::/81
via: 2001:41d0:2:94ff:ff:ff:ff:ff
- to: 2001:41d0:2:9434:0:4000::/82
via: 2001:41d0:2:94ff:ff:ff:ff:ff
- to: 2001:41d0:2:94ff:ff:4000::/82
via: 2001:41d0:2:94ff:ff:ff:ff:ff
- to: 2001:41d0:2:9434:0:2000::/83
via: 2001:41d0:2:94ff:ff:ff:ff:ff
- to: 2001:41d0:2:94ff:ff:2000::/83
via: 2001:41d0:2:94ff:ff:ff:ff:ff
- to: 2001:41d0:2:9434:0:1000::/84
via: 2001:41d0:2:94ff:ff:ff:ff:ff
- to: 2001:41d0:2:94ff:ff:1000::/84
via: 2001:41d0:2:94ff:ff:ff:ff:ff
- to: 2001:41d0:2:9434:0:800::/85
via: 2001:41d0:2:94ff:ff:ff:ff:ff
- to: 2001:41d0:2:94ff:ff:800::/85
via: 2001:41d0:2:94ff:ff:ff:ff:ff
- to: 2001:41d0:2:9434:0:400::/86
via: 2001:41d0:2:94ff:ff:ff:ff:ff
- to: 2001:41d0:2:94ff:ff:400::/86
via: 2001:41d0:2:94ff:ff:ff:ff:ff
- to: 2001:41d0:2:9434:0:200::/87
via: 2001:41d0:2:94ff:ff:ff:ff:ff
- to: 2001:41d0:2:94ff:ff:200::/87
via: 2001:41d0:2:94ff:ff:ff:ff:ff
- to: 2001:41d0:2:9434:0:100::/88
via: 2001:41d0:2:94ff:ff:ff:ff:ff
- to: 2001:41d0:2:94ff:ff:100::/88
via: 2001:41d0:2:94ff:ff:ff:ff:ff
- to: 2001:41d0:2:9434:0:80::/89
via: 2001:41d0:2:94ff:ff:ff:ff:ff
- to: 2001:41d0:2:94ff:ff::/89
via: 2001:41d0:2:94ff:ff:ff:ff:ff
- to: 2001:41d0:2:9434:0:40::/90
via: 2001:41d0:2:94ff:ff:ff:ff:ff
- to: 2001:41d0:2:94ff:ff:80::/90
via: 2001:41d0:2:94ff:ff:ff:ff:ff
- to: 2001:41d0:2:9434:0:20::/91
via: 2001:41d0:2:94ff:ff:ff:ff:ff
- to: 2001:41d0:2:94ff:ff:c0::/91
via: 2001:41d0:2:94ff:ff:ff:ff:ff
- to: 2001:41d0:2:9434:0:10::/92
via: 2001:41d0:2:94ff:ff:ff:ff:ff
- to: 2001:41d0:2:94ff:ff:e0::/92
via: 2001:41d0:2:94ff:ff:ff:ff:ff
- to: 2001:41d0:2:9434:0:8::/93
via: 2001:41d0:2:94ff:ff:ff:ff:ff
- to: 2001:41d0:2:94ff:ff:f0::/93
via: 2001:41d0:2:94ff:ff:ff:ff:ff
- to: 2001:41d0:2:9434:0:4::/94
via: 2001:41d0:2:94ff:ff:ff:ff:ff
- to: 2001:41d0:2:94ff:ff:f8::/94
via: 2001:41d0:2:94ff:ff:ff:ff:ff
- to: 2001:41d0:2:9434:0:2::/95
via: 2001:41d0:2:94ff:ff:ff:ff:ff
- to: 2001:41d0:2:94ff:ff:fc::/95
via: 2001:41d0:2:94ff:ff:ff:ff:ff
- to: 2001:41d0:2:9434:0:1::/96
via: 2001:41d0:2:94ff:ff:ff:ff:ff
- to: 2001:41d0:2:94ff:ff:fe::/96
via: 2001:41d0:2:94ff:ff:ff:ff:ff
- to: 2001:41d0:2:9434::8000:0/97
via: 2001:41d0:2:94ff:ff:ff:ff:ff
- to: 2001:41d0:2:94ff:ff:ff:8000:0/97
via: 2001:41d0:2:94ff:ff:ff:ff:ff
- to: 2001:41d0:2:9434::4000:0/98
via: 2001:41d0:2:94ff:ff:ff:ff:ff
- to: 2001:41d0:2:94ff:ff:ff:4000:0/98
via: 2001:41d0:2:94ff:ff:ff:ff:ff
- to: 2001:41d0:2:9434::2000:0/99
via: 2001:41d0:2:94ff:ff:ff:ff:ff
- to: 2001:41d0:2:94ff:ff:ff:2000:0/99
via: 2001:41d0:2:94ff:ff:ff:ff:ff
- to: 2001:41d0:2:9434::1000:0/100
via: 2001:41d0:2:94ff:ff:ff:ff:ff
- to: 2001:41d0:2:94ff:ff:ff:1000:0/100
via: 2001:41d0:2:94ff:ff:ff:ff:ff
- to: 2001:41d0:2:9434::800:0/101
via: 2001:41d0:2:94ff:ff:ff:ff:ff
- to: 2001:41d0:2:94ff:ff:ff:800:0/101
via: 2001:41d0:2:94ff:ff:ff:ff:ff
- to: 2001:41d0:2:9434::400:0/102
via: 2001:41d0:2:94ff:ff:ff:ff:ff
- to: 2001:41d0:2:94ff:ff:ff:400:0/102
via: 2001:41d0:2:94ff:ff:ff:ff:ff
- to: 2001:41d0:2:9434::200:0/103
via: 2001:41d0:2:94ff:ff:ff:ff:ff
- to: 2001:41d0:2:94ff:ff:ff:200:0/103
via: 2001:41d0:2:94ff:ff:ff:ff:ff
- to: 2001:41d0:2:9434:
0/104
via: 2001:41d0:2:94ff:ff:ff:ff:ff
- to: 2001:41d0:2:94ff:ff:ff:100:0/104
via: 2001:41d0:2:94ff:ff:ff:ff:ff
- to: 2001:41d0:2:9434::80:0/105
via: 2001:41d0:2:94ff:ff:ff:ff:ff
- to: 2001:41d0:2:94ff:ff:ff::/105
via: 2001:41d0:2:94ff:ff:ff:ff:ff
- to: 2001:41d0:2:9434::40:0/106
via: 2001:41d0:2:94ff:ff:ff:ff:ff
- to: 2001:41d0:2:94ff:ff:ff:80:0/106
via: 2001:41d0:2:94ff:ff:ff:ff:ff
- to: 2001:41d0:2:9434::20:0/107
via: 2001:41d0:2:94ff:ff:ff:ff:ff
- to: 2001:41d0:2:94ff:ff:ff:c0:0/107
via: 2001:41d0:2:94ff:ff:ff:ff:ff
- to: 2001:41d0:2:9434::10:0/108
via: 2001:41d0:2:94ff:ff:ff:ff:ff
- to: 2001:41d0:2:94ff:ff:ff:e0:0/108
via: 2001:41d0:2:94ff:ff:ff:ff:ff
- to: 2001:41d0:2:9434::8:0/109
via: 2001:41d0:2:94ff:ff:ff:ff:ff
- to: 2001:41d0:2:94ff:ff:ff:f0:0/109
via: 2001:41d0:2:94ff:ff:ff:ff:ff
- to: 2001:41d0:2:9434::4:0/110
via: 2001:41d0:2:94ff:ff:ff:ff:ff
- to: 2001:41d0:2:94ff:ff:ff:f8:0/110
via: 2001:41d0:2:94ff:ff:ff:ff:ff
- to: 2001:41d0:2:9434::2:0/111
via: 2001:41d0:2:94ff:ff:ff:ff:ff
- to: 2001:41d0:2:94ff:ff:ff:fc:0/111
via: 2001:41d0:2:94ff:ff:ff:ff:ff
- to: 2001:41d0:2:9434::1:0/112
via: 2001:41d0:2:94ff:ff:ff:ff:ff
- to: 2001:41d0:2:94ff:ff:ff:fe:0/112
via: 2001:41d0:2:94ff:ff:ff:ff:ff
- to: 2001:41d0:2:9434::8000/113
via: 2001:41d0:2:94ff:ff:ff:ff:ff
- to: 2001:41d0:2:94ff:ff:ff:ff:8000/113
via: 2001:41d0:2:94ff:ff:ff:ff:ff
- to: 2001:41d0:2:9434::4000/114
via: 2001:41d0:2:94ff:ff:ff:ff:ff
- to: 2001:41d0:2:94ff:ff:ff:ff:4000/114
via: 2001:41d0:2:94ff:ff:ff:ff:ff
- to: 2001:41d0:2:9434::2000/115
via: 2001:41d0:2:94ff:ff:ff:ff:ff
- to: 2001:41d0:2:94ff:ff:ff:ff:2000/115
via: 2001:41d0:2:94ff:ff:ff:ff:ff
- to: 2001:41d0:2:9434::1000/116
via: 2001:41d0:2:94ff:ff:ff:ff:ff
- to: 2001:41d0:2:94ff:ff:ff:ff:1000/116
via: 2001:41d0:2:94ff:ff:ff:ff:ff
- to: 2001:41d0:2:9434::800/117
via: 2001:41d0:2:94ff:ff:ff:ff:ff
- to: 2001:41d0:2:94ff:ff:ff:ff:800/117
via: 2001:41d0:2:94ff:ff:ff:ff:ff
- to: 2001:41d0:2:9434::400/118
via: 2001:41d0:2:94ff:ff:ff:ff:ff
- to: 2001:41d0:2:94ff:ff:ff:ff:400/118
via: 2001:41d0:2:94ff:ff:ff:ff:ff
- to: 2001:41d0:2:9434::200/119
via: 2001:41d0:2:94ff:ff:ff:ff:ff
- to: 2001:41d0:2:94ff:ff:ff:ff:200/119
via: 2001:41d0:2:94ff:ff:ff:ff:ff
- to: 2001:41d0:2:9434::100/120
via: 2001:41d0:2:94ff:ff:ff:ff:ff
- to: 2001:41d0:2:94ff:ff:ff:ff:100/120
via: 2001:41d0:2:94ff:ff:ff:ff:ff
- to: 2001:41d0:2:9434::80/121
via: 2001:41d0:2:94ff:ff:ff:ff:ff
- to: 2001:41d0:2:94ff:ff:ff:ff:0/121
via: 2001:41d0:2:94ff:ff:ff:ff:ff
- to: 2001:41d0:2:9434::40/122
via: 2001:41d0:2:94ff:ff:ff:ff:ff
- to: 2001:41d0:2:94ff:ff:ff:ff:80/122
via: 2001:41d0:2:94ff:ff:ff:ff:ff
- to: 2001:41d0:2:9434::20/123
via: 2001:41d0:2:94ff:ff:ff:ff:ff
- to: 2001:41d0:2:94ff:ff:ff:ff:c0/123
via: 2001:41d0:2:94ff:ff:ff:ff:ff
- to: 2001:41d0:2:9434::10/124
via: 2001:41d0:2:94ff:ff:ff:ff:ff
- to: 2001:41d0:2:94ff:ff:ff:ff:e0/124
via: 2001:41d0:2:94ff:ff:ff:ff:ff
- to: 2001:41d0:2:9434::8/125
via: 2001:41d0:2:94ff:ff:ff:ff:ff
- to: 2001:41d0:2:94ff:ff:ff:ff:f0/125
via: 2001:41d0:2:94ff:ff:ff:ff:ff
- to: 2001:41d0:2:9434::4/126
via: 2001:41d0:2:94ff:ff:ff:ff:ff
- to: 2001:41d0:2:94ff:ff:ff:ff:f8/126
via: 2001:41d0:2:94ff:ff:ff:ff:ff
- to: 2001:41d0:2:9434::2/127
via: 2001:41d0:2:94ff:ff:ff:ff:ff
- to: 2001:41d0:2:94ff:ff:ff:ff:fc/127
via: 2001:41d0:2:94ff:ff:ff:ff:ff
- to: 2001:41d0:2:9434::/128
via: 2001:41d0:2:94ff:ff:ff:ff:ff
- to: 2001:41d0:2:94ff:ff:ff:ff:fe/128
via: 2001:41d0:2:94ff:ff:ff:ff:ff
set-name: eno1
Hello @AdamR, I'll assume you're on Ubuntu 22.04 because we removed this for Ubuntu 23.10.
The routes are one way to handle the fact that the gateway is not inside your server's network which is typically a /64. The routes are for all IPs which are inside the /56 but not the /64, if you remove them, you won't be able to reach these.
We moved away from this configuration in more recent OSes but we did not want to change this for existing OSes like Ubuntu 22.04.
If you want to get rid of the routes, you need to :
* Use the proper netmask (likely /64).
* Mark the route as on-link.
Please install Ubuntu 23.10 on of your server to see what a working netplan configuration looks like without the extra routes. It should look like:
```yaml
routes:
- on-link: true
to: default
via: 2001:41d0:2:94ff:ff:ff:ff:ff
```