Description of problem:

L3 Egress traffic from pod in segmented network does not work.

Version-Release number of selected component (if applicable):

build openshift/ovn-kubernetes#2274,openshift/api#2005

oc version

Client Version: 4.15.9
Kustomize Version: v5.0.4-0.20230601165947-6ce0bf390ce3
Server Version: 4.17.0-0.ci.test-2024-08-28-123437-ci-ln-v5g4wb2-latest
Kubernetes Version: v1.30.3-dirty
 

How reproducible:

Always

Steps to Reproduce:

1. Create a cluster UPI GCP with build from cluster bot

2. Create a namespace test wih NAD as below

 oc -n test get network-attachment-definition l3-network-nad -oyaml

apiVersion: k8s.cni.cncf.io/v1
kind: NetworkAttachmentDefinition
metadata:
  creationTimestamp: "2024-08-28T17:44:14Z"
  generation: 1
  name: l3-network-nad
  namespace: test
  resourceVersion: "108224"
  uid: 5db4ca26-39dd-45b7-8016-215664e21f5d
spec:
  config: |
    {
      "cniVersion": "0.3.1",
      "name": "l3-network",
      "type": "ovn-k8s-cni-overlay",
      "topology":"layer3",
      "subnets": "10.150.0.0/16",
      "mtu": 1300,
      "netAttachDefName": "test/l3-network-nad",
      "role": "primary"
    }

3. Create a pod in the segmented namespace test

oc -n test exec -it hello-pod – ip a

1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN group default qlen 1000
    link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
    inet 127.0.0.1/8 scope host lo
       valid_lft forever preferred_lft forever
    inet6 ::1/128 scope host 
       valid_lft forever preferred_lft forever
2: eth0@if25: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1360 qdisc noqueue state UP group default 
    link/ether 0a:58:0a:83:00:11 brd ff:ff:ff:ff:ff:ff link-netnsid 0
    inet 10.131.0.17/23 brd 10.131.1.255 scope global eth0
       valid_lft forever preferred_lft forever
    inet6 fe80::858:aff:fe83:11/64 scope link 
       valid_lft forever preferred_lft forever
3: ovn-udn1@if26: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1300 qdisc noqueue state UP group default 
    link/ether 0a:58:0a:96:03:03 brd ff:ff:ff:ff:ff:ff link-netnsid 0
    inet 10.150.3.3/24 brd 10.150.3.255 scope global ovn-udn1
       valid_lft forever preferred_lft forever
    inet6 fe80::858:aff:fe96:303/64 scope link 
       valid_lft forever preferred_lft forever

 oc -n test exec -it hello-pod – ip r

default via 10.150.3.1 dev ovn-udn1 
10.128.0.0/14 via 10.131.0.1 dev eth0 
10.131.0.0/23 dev eth0 proto kernel scope link src 10.131.0.17 
10.150.0.0/16 via 10.150.3.1 dev ovn-udn1 
10.150.3.0/24 dev ovn-udn1 proto kernel scope link src 10.150.3.3 
100.64.0.0/16 via 10.131.0.1 dev eth0 
100.65.0.0/16 via 10.150.3.1 dev ovn-udn1 
172.30.0.0/16 via 10.150.3.1 dev ovn-udn1 

4. Try to curl the IP echo server running outside the cluster to see it fail.

 oc -n test exec -it hello-pod – curl 10.0.0.2:9095 --connect-timeout 5

curl: (28) Connection timeout after 5001 ms
command terminated with exit code 28
 

Actual results:

curl request fails

Expected results:

curl request should pass

Additional info:

The egress from pod in regular namespace works 

 oc -n test1 exec -it hello-pod – curl 10.0.0.2:9095 --connect-timeout 5

10.0.128.4

Please fill in the following template while reporting a bug and provide as much relevant information as possible. Doing so will give us the best chance to find a prompt resolution.

Affected Platforms:

Is it an

1. internal CI failure
2. customer issue / SD
3. internal RedHat testing failure

If it is an internal RedHat testing failure:

• Please share a kubeconfig or creds to a live cluster for the assignee to debug/troubleshoot along with reproducer steps (specially if it's a telco use case like ICNI, secondary bridges or BM+kubevirt).

If it is a CI failure:

• Did it happen in different CI lanes? If so please provide links to multiple failures with the same error instance
• Did it happen in both sdn and ovn jobs? If so please provide links to multiple failures with the same error instance
• Did it happen in other platforms (e.g. aws, azure, gcp, baremetal etc) ? If so please provide links to multiple failures with the same error instance
• When did the failure start happening? Please provide the UTC timestamp of the networking outage window from a sample failure run
• If it's a connectivity issue,
• What is the srcNode, srcIP and srcNamespace and srcPodName?
• What is the dstNode, dstIP and dstNamespace and dstPodName?
• What is the traffic path? (examples: pod2pod? pod2external?, pod2svc? pod2Node? etc)

If it is a customer / SD issue:

• Provide enough information in the bug description that Engineering doesn’t need to read the entire case history.
• Don’t presume that Engineering has access to Salesforce.
• Do presume that Engineering will access attachments through supportshell.
• Describe what each relevant attachment is intended to demonstrate (failed pods, log errors, OVS issues, etc).
• Referring to the attached must-gather, sosreport or other attachment, please provide the following details:
  • If the issue is in a customer namespace then provide a namespace inspect.
  • If it is a connectivity issue:
    • What is the srcNode, srcNamespace, srcPodName and srcPodIP?
    • What is the dstNode, dstNamespace, dstPodName and dstPodIP?
    • What is the traffic path? (examples: pod2pod? pod2external?, pod2svc? pod2Node? etc)
    • Please provide the UTC timestamp networking outage window from must-gather
    • Please provide tcpdump pcaps taken during the outage filtered based on the above provided src/dst IPs
  • If it is not a connectivity issue:
    • Describe the steps taken so far to analyze the logs from networking components (cluster-network-operator, OVNK, SDN, openvswitch, ovs-configure etc) and the actual component where the issue was seen based on the attached must-gather. Please attach snippets of relevant logs around the window when problem has happened if any.

• When showing the results from commands, include the entire command in the output.  
• For OCPBUGS in which the issue has been identified, label with “sbr-triaged”
• For OCPBUGS in which the issue has not been identified and needs Engineering help for root cause, label with “sbr-untriaged”
• Do not set the priority, that is owned by Engineering and will be set when the bug is evaluated
• Note: bugs that do not meet these minimum standards will be closed with label “SDN-Jira-template”
• For guidance on using this template please see
  OCPBUGS Template Training for Networking  components