Ubuntu
cloud-init package

  1. Bug #1671951
  2. Comment #31

Comment 31 for bug 1671951

Revision history for this message
Dimitri John Ledkov (xnox) wrote : Re: [Bug 1671951] Re: networkd should allow configuring IPV6 MTU

I thought custom ipv6 MTU may not be lower than ipv4 one.

Hence request for 6000 ipv6 is not valid, when link is on 8958.

Can you try 9000?

On Wed, 28 Aug 2019, 15:41 Ryan Harper, <email address hidden> wrote:

> I launched a bionic image on serverstack, updated the netplan.io to
> proposed, modified the network config to set ipv6-mtu to 6000 and
> rebooted.
>
> root@b-test-ipv6-mtu:~# apt-cache policy netplan.io
> netplan.io:
> Installed: 0.98-0ubuntu1~18.04.1
> Candidate: 0.98-0ubuntu1~18.04.1
> Version table:
> *** 0.98-0ubuntu1~18.04.1 500
> 500 http://nova.clouds.archive.ubuntu.com/ubuntu
> bionic-proposed/main amd64 Packages
> 100 /var/lib/dpkg/status
> 0.97-0ubuntu1~18.04.1 500
> 500 http://nova.clouds.archive.ubuntu.com/ubuntu
> bionic-updates/main amd64 Packages
> 0.40.1~18.04.4 500
> 500 http://security.ubuntu.com/ubuntu bionic-security/main amd64
> Packages
> 0.36.1 500
> 500 http://nova.clouds.archive.ubuntu.com/ubuntu bionic/main
> amd64 Packages
>
> root@b-test-ipv6-mtu:~# cat /etc/netplan/50-cloud-init.yaml
> network:
> version: 2
> ethernets:
> ens3:
> dhcp4: true
> match:
> macaddress: fa:16:3e:4d:3c:6a
> set-name: ens3
> ipv6-mtu: 6000
>
> root@b-test-ipv6-mtu:/run/systemd/network# cat 10-netplan-ens3.link
> [Match]
> MACAddress=fa:16:3e:4d:3c:6a
>
> [Link]
> Name=ens3
> WakeOnLan=off
> root@b-test-ipv6-mtu:/run/systemd/network# cat 10-netplan-ens3.network
> [Match]
> MACAddress=fa:16:3e:4d:3c:6a
> Name=ens3
>
> [Network]
> DHCP=ipv4
> LinkLocalAddressing=ipv6
> IPv6MTUBytes=6000
>
> [DHCP]
> RouteMetric=100
> UseMTU=true
>
>
> ~# cat /sys/class/net/ens3/mtu
> 8958
> ~# sysctl net.ipv6.conf.ens3.mtu
> net.ipv6.conf.ens3.mtu = 8958
>
> --
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> https://bugs.launchpad.net/bugs/1671951
>
> Title:
> networkd should allow configuring IPV6 MTU
>
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