Question about Traefik config for TrafficSplit services

Traefik Mesh
1

Hi, there!

While testing Traffic Splitting, I got the full Traefik config as below:

{
  "http": {
    "routers": {
      "readiness": {
        "entryPoints": [
          "readiness"
        ],
        "service": "readiness",
        "rule": "Path(`/ping`)"
      },
      "test-server-80": {
        "entryPoints": [
          "http-5000"
        ],
        "service": "test-server-80",
        "rule": "Host(`server.test.traefik.mesh`) || Host(`server.test.maesh`) || Host(`10.96.11.122`)",
        "priority": 1002
      },
      "test-server-server-split-80-traffic-split-direct": {
        "entryPoints": [
          "http-5000"
        ],
        "service": "test-server-server-split-80-traffic-split",
        "rule": "Host(`server.test.traefik.mesh`) || Host(`server.test.maesh`) || Host(`10.96.11.122`)",
        "priority": 4002
      },
      "test-server-v1-80": {
        "entryPoints": [
          "http-5000"
        ],
        "service": "test-server-v1-80",
        "rule": "Host(`server-v1.test.traefik.mesh`) || Host(`server-v1.test.maesh`) || Host(`10.96.156.206`)",
        "priority": 1002
      },
      "test-server-v2-80": {
        "entryPoints": [
          "http-5000"
        ],
        "service": "test-server-v2-80",
        "rule": "Host(`server-v2.test.traefik.mesh`) || Host(`server-v2.test.maesh`) || Host(`10.96.35.77`)",
        "priority": 1002
      }
    },
    "services": {
      "block-all-service": {
        "loadBalancer": {
          "passHostHeader": false
        }
      },
      "readiness": {
        "loadBalancer": {
          "servers": [
            {
              "url": "http://127.0.0.1:8080"
            }
          ],
          "passHostHeader": true
        }
      },
      "test-server-80": {
        "loadBalancer": {
          "servers": [
            {
              "url": "http://10.244.1.13:80"
            },
            {
              "url": "http://10.244.1.15:80"
            },
            {
              "url": "http://10.244.1.16:80"
            },
            {
              "url": "http://10.244.2.12:80"
            },
            {
              "url": "http://10.244.2.13:80"
            },
            {
              "url": "http://10.244.2.14:80"
            }
          ],
          "passHostHeader": true
        }
      },
      "test-server-server-split-80-server-v1-traffic-split-backend": {
        "loadBalancer": {
          "servers": [
            {
              "url": "http://server-v1.test.traefik.mesh:80"
            }
          ],
          "passHostHeader": false
        }
      },
      "test-server-server-split-80-server-v2-traffic-split-backend": {
        "loadBalancer": {
          "servers": [
            {
              "url": "http://server-v2.test.traefik.mesh:80"
            }
          ],
          "passHostHeader": false
        }
      },
      "test-server-server-split-80-traffic-split": {
        "weighted": {
          "services": [
            {
              "name": "test-server-server-split-80-server-v1-traffic-split-backend",
              "weight": 10
            },
            {
              "name": "test-server-server-split-80-server-v2-traffic-split-backend",
              "weight": 90
            }
          ]
        }
      },
      "test-server-v1-80": {
        "loadBalancer": {
          "servers": [
            {
              "url": "http://10.244.1.16:80"
            },
            {
              "url": "http://10.244.2.14:80"
            }
          ],
          "passHostHeader": true
        }
      },
      "test-server-v2-80": {
        "loadBalancer": {
          "servers": [
            {
              "url": "http://10.244.1.15:80"
            },
            {
              "url": "http://10.244.2.13:80"
            }
          ],
          "passHostHeader": true
        }
      }
    },
    "middlewares": {
      "block-all-middleware": {
        "ipWhiteList": {
          "sourceRange": [
            "255.255.255.255"
          ]
        }
      }
    }
  }
}

I'm wondering why the urls of the following services are specified as hosts (instead of IPs), which themselves, to my understanding, will (again) be resolved to the IPs of Traefik Mesh Proxy:

...
"test-server-server-split-80-server-v1-traffic-split-backend": {
        "loadBalancer": {
          "servers": [
            {
              "url": "http://server-v1.test.traefik.mesh:80"
            }
          ],
          "passHostHeader": false
        }
      },
      "test-server-server-split-80-server-v2-traffic-split-backend": {
        "loadBalancer": {
          "servers": [
            {
              "url": "http://server-v2.test.traefik.mesh:80"
            }
          ],
          "passHostHeader": false
        }
      },
...

If I'm not mistaken, I guess this will add one more hop when forwarding traffic to the real backend server. Why not to use pod IPs directly in this scenario? What's the idea behind this design?

Thanks in advance!