i have made 1 microservice user microservice. its application.yaml file looks something like this

server:
  port: 5001

spring:
  application:
    name: USER-SERVICE
  datasource:
    url: #
    username: #
    password: #
  jpa:
    hibernate:
      ddl-auto: update

eureka:
  instance:
    prefer-ip-address: true
  client:
    fetch-registry: true
    register-with-eureka: true
    serviceUrl:
      defaultZone: http://localhost:8081/eureka/

i have made eureka server and the above microservice is registered to this server as well.
the application.yaml for this server is:

server:
  port: 8081

eureka:
  instance:
    hostname: localhost
  client:
    register-with-eureka: false
    fetch-registry: false
    serviceUrl:
      defaultZone: http://${eureka.instance.hostname}:${server.port}/eureka/

now what i have done is i made a cloud gateway using reactive gateway dependency to route all microservice endpoints from here.
the application.yaml file is:

spring:
  application:
    name: GATEWAY-SERVICE
  cloud:
    gateway:
      routes:      #setup paths here
        - id: USER-SERVICE
          uri: lb://USER-SERVICE
          predicates:
            - Path=/auth/**, /api/user/**

      default-filters:   #setup cors here
        - DedupeResponseHeader=Access-Control-Allow-Credentials Access-Control-Allow-Origin

      globalcors:        #setup cors here
        cors-configurations:
            '[/**]':
              allowedOrigins: "*"
              allowedMethods: "*"
              allowedHeaders: "*"

server:
  port: 6500

eureka:
  instance:
    prefer-ip-address: true
  client:
    fetch-registry: true
    register-with-eureka: true
    serviceUrl:
      defaultZone: http://localhost:8081/eureka/

and this gateway is also registered with eureka server. now when i go to http://localhost:8081

i can see 2 microservices, one for user service and another for gateway are coming up and they are UP.
their status looks like this

 192.168.1.4:USER-SERVICE:5001
 192.168.1.4:GATEWAY-SERVICE:6500

now when i hit http://localhost:6500/auth/login from postman, i get 500 error and there are no errors in user service console but there is an error in gateway service.

io.netty.channel.AbstractChannel$AnnotatedConnectException: Connection timed out: no further information: /192.168.1.4:5001
    Suppressed: reactor.core.publisher.FluxOnAssembly$OnAssemblyException: 
Error has been observed at the following site(s):
    *__checkpoint ⇢ org.springframework.cloud.gateway.filter.WeightCalculatorWebFilter [DefaultWebFilterChain]
    *__checkpoint ⇢ HTTP POST "/auth/login" [ExceptionHandlingWebHandler]
Original Stack Trace:
Caused by: java.net.ConnectException: Connection timed out: no further information
    at java.base/sun.nio.ch.Net.pollConnect(Native Method) ~[na:na]
    at java.base/sun.nio.ch.Net.pollConnectNow(Net.java:682) ~[na:na]
    at java.base/sun.nio.ch.SocketChannelImpl.finishConnect(SocketChannelImpl.java:973) ~[na:na]
    at io.netty.channel.socket.nio.NioSocketChannel.doFinishConnect(NioSocketChannel.java:337) ~[netty-transport-4.1.109.Final.jar:4.1.109.Final]
    at io.netty.channel.nio.AbstractNioChannel$AbstractNioUnsafe.finishConnect(AbstractNioChannel.java:339) ~[netty-transport-4.1.109.Final.jar:4.1.109.Final]
    at io.netty.channel.nio.NioEventLoop.processSelectedKey(NioEventLoop.java:776) ~[netty-transport-4.1.109.Final.jar:4.1.109.Final]
    at io.netty.channel.nio.NioEventLoop.processSelectedKeysOptimized(NioEventLoop.java:724) ~[netty-transport-4.1.109.Final.jar:4.1.109.Final]
    at io.netty.channel.nio.NioEventLoop.processSelectedKeys(NioEventLoop.java:650) ~[netty-transport-4.1.109.Final.jar:4.1.109.Final]
    at io.netty.channel.nio.NioEventLoop.run(NioEventLoop.java:562) ~[netty-transport-4.1.109.Final.jar:4.1.109.Final]
    at io.netty.util.concurrent.SingleThreadEventExecutor$4.run(SingleThreadEventExecutor.java:997) ~[netty-common-4.1.109.Final.jar:4.1.109.Final]
    at io.netty.util.internal.ThreadExecutorMap$2.run(ThreadExecutorMap.java:74) ~[netty-common-4.1.109.Final.jar:4.1.109.Final]
    at io.netty.util.concurrent.FastThreadLocalRunnable.run(FastThreadLocalRunnable.java:30) ~[netty-common-4.1.109.Final.jar:4.1.109.Final]
    at java.base/java.lang.Thread.run(Thread.java:1583) ~[na:na]

one more thing, this complete setup is running on my local machine.
i am unable to figure this out. help needed. if you need any other code, i can add it.