# Network Errors Troubleshooting Guide

**Last Updated**: 2025-10-22

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## gRPC Connection Refused

### Symptom: `connect: connection refused`

**Diagnosis**:
```bash
# Check service is running
kubectl get pods -n foxhunt -l app.kubernetes.io/component=trading-service

# Check service endpoint
kubectl get endpoints -n foxhunt foxhunt-trading-service

# Test connection
grpc_health_probe -addr=foxhunt-trading-service.foxhunt.svc.cluster.local:50052
```

**Resolution**:
```bash
# Restart service
kubectl rollout restart deployment/foxhunt-trading-service -n foxhunt

# Check logs for startup errors
kubectl logs -n foxhunt -l app.kubernetes.io/component=trading-service --tail=100
```

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## DNS Resolution Failures

### Symptom: `no such host`

**Diagnosis**:
```bash
# Check CoreDNS
kubectl get pods -n kube-system -l k8s-app=kube-dns

# Test DNS resolution
kubectl run -it --rm debug --image=nicolaka/netshoot --restart=Never -- \
    nslookup foxhunt-postgresql.foxhunt.svc.cluster.local
```

**Resolution**:
```bash
# Restart CoreDNS
kubectl delete pods -n kube-system -l k8s-app=kube-dns

# Verify DNS resolution
kubectl run -it --rm debug --image=nicolaka/netshoot --restart=Never -- \
    dig foxhunt-postgresql.foxhunt.svc.cluster.local
```

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**End of Network Errors Troubleshooting Guide**