VMware Edge Docker network subnet can conflict with workload subnet

Products

• VMware NSX

Issue/Introduction

• Running on VMware NSX Edge Node :  4.x
• The internal docker0 Interface subnet "169.17.0.0/16" on the Edge node conflicts with any existing workload subnet.
• To confirm the configuration of docker0 interface , run ifconfig from the root of the Edge node:
  root@edge01:~# ifconfig
  docker0: flags=4099<UP,BROADCAST,MULTICAST>  mtu 1500
          inet 169.17.0.1  netmask 255.255.0.0  broadcast 169.17.255.255
          inet6 fe80::42:9bff:fed6:8493  prefixlen 64  scopeid 0x20<link>
          ether 02:42:9b:d6:84:93  txqueuelen 0  (Ethernet)
          RX packets 3  bytes 180 (180.0 B)
          RX errors 0  dropped 0  overruns 0  frame 0
          TX packets 2  bytes 196 (196.0 B)
          TX errors 0  dropped 0 overruns 0  carrier 0  collisions 0
  
  

NOTE: The preceding log excerpts are only examples. Date, time and environmental variables may vary depending on your environment.

Environment

VMware NSX 

Cause

Docker is installed in VMware NSX Edge 4.x version 

Resolution

• Change docker0 subnet:
  - login as root to an Edge node.
  - Edit the following file /etc/docker/daemon.json or create it if it does not exist. Add below json :
  root@Edge-01:/etc/docker# vim daemon.json
  {
  "bip": "169.17.0.1/16" >>> Enter the subnet you would like to use here
  } :
  - Restart the docker service:
  root@Edge-01:/etc/docker# systemctl restart docker
  
  
  Note: If the above modification are done putting the Edge node is maintaince mode then we do not require to restart the docker service.

Additional Information

• The changes made to the docker0 interface will remain persistent after the Edge node is rebooted.
• Please refer to the kb which explain the process to change the docker0 interface subnet on the NSX Manger's Nodes.: VMware NSX 4.1.0 docker network subnet can conflict with workload subnet