MTU problem in VXLAN

[Mapashito]

Hi,

I have created a vxlan network in SDN zone. I've configured MTU to 1450 in zone and vm interfaces over vxlan to 1450 too.



It's works, but if I have virtual network into the vm (docker for example), it is not working, I need to configure virtual network into vm with 1450 mtu. I think it is not correct, it is not "transparent", because I don't have to know the virtual machine content.
is there any alternative?

 

[Tivin-i]

From my testing, docker creates a bridge with a 1500 MTU by default, and so I either manually adjusted that in /etc/docker/daemon.json:

{
    "mtu": 1450
}

You will need to create the file if it doesn't exist, and restart docker service afterwards.

if you work with docker compose and stacks, I change the networks for containers and append the code below in the compose file, as it creates a new bridge for every stack:

networks:
  custom-network:
    driver: bridge
    driver_opts:
      com.docker.network.driver.mtu: "1450" # Set MTU

 

[spirit]

Hi,

I have created a vxlan network in SDN zone. I've configured MTU to 1450 in zone and vm interfaces over vxlan to 1450 too.
View attachment 64827

View attachment 64828
It's works, but if I have virtual network into the vm (docker for example), it is not working, I need to configure virtual network into vm with 1450 mtu. I think it is not correct, it is not "transparent", because I don't have to know the virtual machine content.
is there any alternative?

The only alternative is to increase the mtu on your physical switches