In https://kubernetes.github.io/ingress-nginx/deploy/baremetal/ In metalLB mode, one node attracts all the traffic for the ingress-nginx By node port we can gather all traffic and loadbalance it podes by service
what is diffrence between node port and metalLB?
It's detailed fairly well here in the Kubernetes Service here:
https://kubernetes.io/docs/concepts/services-networking/service/#publishing-services-service-types
To summarise:
NodePort exposes the service on a port, which can then be accessed externally.
LoadBalancer uses a Cloud Providers option for exposing a port. E.G. Azure Load Balancers are used and can potentially expose multiple public IP addresses and load balances them against a larger pool of backend resources (Kubernetes nodes)