networkd does not accept / set advertised mtu
Affects | Status | Importance | Assigned to | Milestone | |
---|---|---|---|---|---|
nplan (Ubuntu) |
Fix Released
|
Critical
|
Dimitri John Ledkov | ||
Xenial |
Fix Released
|
Undecided
|
Unassigned | ||
Zesty |
Fix Released
|
Undecided
|
Unassigned | ||
systemd (Ubuntu) |
Fix Released
|
Undecided
|
Unassigned | ||
Xenial |
Fix Released
|
Undecided
|
Unassigned |
Bug Description
[Impact]
Hosts may require a specific MTU to be set as passed by DHCP options. We should honor these settings to ensure proper communication of the host with the rest of the network.
[Test case]
1) Run netplan on a system that should receive MTU settings from DHCP.
2) Validate that the MTU configuration provided by DHCP is applied to the right interface.
[Regression Potential]
If DHCP settings specify an invalid MTU setting which is currently being ignored and letting the systems communicate correctly with the network, then these systems would regress.
---
<wgrant> Right, so as far as I can tell the neutron-api on lcy01 is configured to advertise an instance interface MTU of 1400, though that's lower than it has to be, and the new DHCP setup with networkd just doesn't respect that DHCP option.
Changed in nplan (Ubuntu): | |
status: | New → Fix Committed |
importance: | Undecided → Critical |
assignee: | nobody → Dimitri John Ledkov (xnox) |
Changed in systemd (Ubuntu): | |
status: | New → Fix Committed |
description: | updated |
Changed in systemd (Ubuntu Xenial): | |
status: | New → In Progress |
<wgrant> netplan needs to set DHCP.UseMTU=yes
<wgrant> If I do that, my local instance no longer behaves strangely, and the MTU is correctly 1458