Egress traffic to egress gateway labelled Node's interface dropped when Egress subnet is configured different from node's network

[rajnkamr]

Describe the bug

Configure egress network other than node's network
Antrea should route Egress traffic to the specified gateway
egrssscrdresource. yaml

apiVersion: crd.antrea.io/v1beta1
kind: Egress
metadata:
  name: snat-testapp-ip
spec:
  appliedTo:
    podSelector:
      matchLabels:
        app: antrea-test-app  ###Select the Pods to which the SNAT Policy will be applied
  externalIPPool: external-ip-pool1

externalippoolcrdresource.yaml
apiVersion: crd.antrea.io/v1beta1
kind: ExternalIPPool
metadata:
  name: external-ip-pool1
spec:
  ipRanges:
  - start: 10.10.0.2
    end: 10.10.0.10
  subnetInfo:
    gateway: 10.10.0.1
    prefixLength: 24
    vlan: 10
  nodeSelector:
    matchLabels:
      network-role: egress-gateway

label the node to be used as egress node
kubectl label nodes nodes-worker network-role=egress-gateway

Egress interface is created

28: antrea-ext.10@eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue state UP group default
    link/ether 02:42:ac:12:00:04 brd ff:ff:ff:ff:ff:ff
    inet 10.10.0.2/24 brd 10.10.0.255 scope global antrea-ext.10
       valid_lft forever preferred_lft forever

route is added
10.10.0.0/24 dev antrea-ext.10 proto kernel scope link src 10.10.0.2

egress gateway is reachable from node via default interface

root@nodes-worker:/# ping 10.10.0.1 -I eth0
PING 10.10.0.1 (10.10.0.1) from 172.18.0.4 eth0: 56(84) bytes of data.
64 bytes from 10.10.0.1: icmp_seq=1 ttl=64 time=0.134 ms

To Reproduce

Apply crd resource yaml specified above
try to communicate to external network from pod on egress-gateway labelled node/or any other pod on any other node.
capture traffic at egress gateway labeled node's egress interface using tcpdump
No traffic is seen at the egress interface(antrea-ext.10) on node

Expected

External Traffic should be routed to gateway 10.10.0.1(configured as separate interface for external reachability)
Actual behavior

Egress Traffic not seen at gateway interface
Versions:

Additional context

[tnqn]

It's really hard to read and understand this issue due to the format and missing punctuation. To make it understandable, could you format yaml/command output using markdown syntax and break paragraphs using empty lines?

For the issue itself, given you can ping the gateway 10.10.0.1 from eth0 which is not a VLAN interface, I doubt if the gateway really expects VLAN tag. Can you check if it's still reachable if you don't specify -I eth0 (and why you need to specify it in the first place)?