Description of problem: [EIP UDN layer2 pre-merge testing] in SGW mode, egress packets from a remote EIP pod can not be captured on egress node that was added into cluster as a new node

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

How reproducible:

Steps to Reproduce:

1. on a cluster (in SGW mode), created a new machineset with 2 new nodes, after new nodes are in Ready state, picked one new node as egress node, labeled it with 
k8s.ovn.org/egress-assignable=true
2. Created two namespaces ns1, ns2, in first namespace ns1, created a layer3 UDN; in second namespace ns2, created a layer2 UDN, label both namespaces with a label that matches namespaceSelector defined in egressIP object that is stepped in step 3

3. Create a egressIP object, egressIP was assigned onto the egress node correctly

4. Create a test pod in each namespace on a non-egress node, label the test pod with a lebl that matches the podSelector defined in egressIP object

5. From each test pod, curl external, used tcpdump to capture egress packets on egress node, egress packets were captured on egress node when curl from test pod of namespace ns1, egress packets were not captured on egress node when curl from test pod of namespace ns2

Actual results:  egress packets were not captured on egress node when curl from test pod of namespace ns2

Expected results: egress packets should be captured on egress node when curl from test pod of namespace ns2, and egressIP is used as source IP of packets

Additional info:

For comparison, egressIP from layer3 UDN in namespace ns1 worked correctly when egressIP is assigned on new node.

 https://drive.google.com/file/d/1Ebkf7ZO6Hk0MvqOMyeRmrZEsiL1epNIj/view?usp=drive_linktcpdump:

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