ping -c 3 -I oaitun_ue1 8.8.8.8 does not work with UPF n6

Hi,

I implemented OAI-5G Core basic and OAI-ORAN with multus activated for multiple interfaces such as n2, n3, n4, f1, e1, etc. version v2.1.0

Everything seems to work well, I can ping from UE with ping -c 3 -I oaitun_ue1 12.1.1.1 but the ping -c 3 -I oaitun_ue1 8.8.8.8 does not work.

When I turned off n6 interface to use eth0, the ping -c 3 -I oaitun_ue1 8.8.8.8 works perfectly.

I have tried to add different route configs in UPF pod but nothing works. It does not allow to access DNN/service from interface n6 in UPF pod.

The ping 8.8.8.8 from UPF pod defaultly routes through eth0 while no route is available for n6

Any suggestions for finding the issue or missing configurations are so appreciated.

Below are my configurations of UPF:

In config.yaml:

n6:
  interface_name: n6

In values.yaml:

oai-upf:
...
 # I add security context to use ip command in UPF pod
 securityContext:
   capabilities:
     add: ["NET_ADMIN"]
 multus:
    ## If you don't want to add a default route in your pod then replace this field with ""
    defaultGateway: ""
    n3Interface:
      create: true #false
      ipAdd: 10.1.3.18 #"172.21.8.95"
      netmask: "22"
      name: "n3"
      ## If you do not have a gateway leave the field empty
      gateway: ""
      ## If you don't want to add a default route in your pod then replace this field with ""
      routes: "" #[{'dst': '10.8.0.0/24','gw': '172.21.11.254'}, {'dst': '10.9.0.0/24','gw': '172.21.11.254'}]
      hostInterface: "enp2s0"
    ## For n4 it is better to re-use eth0 interface inside the pod (primary CNI of Kubernetes)
    n4Interface:
      create: true #false
      ipAdd: 10.3.2.17 #"192.168.24.2"
      netmask: "24"
      name: "n4"
      ## If you do not have a gateway leave the field empty
      gateway: ""
      ## If you do not want to add any routes in your pod then leave this field empty
      routes: ""
      hostInterface: "enp2s0"
    n6Interface:
      create: true #false
      ipAdd: 192.168.209.50 # here I use IP with the same range as my host IP: 192.168.209.76 
      name: "n6"
      netmask: "24"
      ## If you do not have a gateway leave the field empty
      gateway: ""
      ## If you do not want to add any routes in your pod then leave this field empty
      routes: ""
      hostInterface: "enp2s0"
...