VLAN MTU 1400

[Janko]

Hello All,

the Hetzner VLAN need a MTU 1400 Size.
I can only set 1492 as minimum.

How can i set 1400?


Version: FreeNAS-11.3-U3.2

 

[Samuel Tai]

Without knowing your setup, I ask are you using NIC option mtu or vlanmtu? These are NIC driver specific. What NIC are you using?

 

[Janko]

Hello Samuel,

sorry, my fault.

Code:

re0: <RealTek 8168/8111 B/C/CP/D/DP/E/F/G PCIe Gigabit Ethernet> port 0xe000-0xe0ff mem 0xf0004000-0xf0004fff,0xf0000000-0xf0003fff irq 16 at device 0.0 on pci3

- VLAN MTU

i can set the 1400 Size under FreeNAS-11.2-U7 without any issues.

 

[Heracles]

RealTek

Realtek NIC are not recommended for FreeNAS. They have a lot of problems. You are highly encouraged to replace it with an Intel NIC...

 

[Janko]

hello Heracles,

i don't have any Problems with RTL but i know it.
My Problem now is the MTU Size under the latest Release.
I cant set 1400.

According to Hetzner:
https://wiki.hetzner.de/index.php/Vswitch/en#IP_addresses

Under FreeNAS-11.2-U7 i can set it via Options.

 

[Samuel Tai]

Unfortunately, this limit of 1492 for option mtu appears to be hard-coded in /usr/local/lib/python3.7/site-packages/middlewared/plugins/network.py, line 708, in FreeNAS 11.3.

Option vlanmtu is NOT restricted. You'll need to set option vlanmtu 1400 on the parent NIC re0.

 

[Samuel Tai]

Alternatively, you could create a post-init task to ifconfig vlan4001 mtu 1400.

 

[Janko]

Hello Samuel,

if i set it via Options, the Server goes offline.
The post-init Task works fine!

Thank you so much :)