Why do ' i/o timeout' occur when I use codeberg.org/miekg/dns?

I had problems using codeberg.org/miekg/dns. When the server starts and the client requests a DNS message, the client will output an i/o timeout. I have been investigating for a long time, but still haven't found a solution. The AI analysis indicates that the windows firewall has blocked tcp. This is the server code:

package main import ( "context" "fmt" "log" "net" "codeberg.org/miekg/dns" "codeberg.org/miekg/dns/dnsutil" ) func main() { handleTCP("tcp") select {} } func handleTCP(net string) { go func() { ds := dns.NewServer() ds.Addr = ":6553" ds.Net = net ds.Handler = dns.HandlerFunc(handleRequest) if err := ds.ListenAndServe(); err != nil { log.Fatalf("Failed to start UDP server: %v", err) } }() log.Println("DNS server started on TCP :53") } func handleRequest(ctx context.Context, w dns.ResponseWriter, r *dns.Msg) { m := new(dns.Msg) // dnsutil.SetReply(m, r) fmt.Printf("%#v\n", r.Question[0]) name, t := dnsutil.Question(r) if len(r.Question) > 0 && t == dns.TypeA { mx := &dns.A{Hdr: dns.Header{Name: name, Class: dns.ClassINET}, A: net.IPv4(192, 168, 1, 1)} m.Answer = append(m.Answer, mx) } if err := m.Pack(); err != nil { log.Fatalf("Failed to pack DNS response: %v", err) } code, err := w.Write(m.Data) if err != nil { log.Fatalf("Failed to write DNS response: %v", err) } log.Println("write bytes : ", code) }

This is the client code:

package main import ( "context" "fmt" "codeberg.org/miekg/dns" "codeberg.org/miekg/dns/dnsutil" ) func main() { ctx := context.Background() m := new(dns.Msg) dnsutil.SetQuestion(m, "miek.nl.", dns.TypeA) m.Pack() c := new(dns.Client) resp, rtt, err := c.Exchange(ctx, m, "tcp", "127.0.0.1:6553") if err != nil { fmt.Println(err) // !!! writeto tcp 127.0.0.1:50714->127.0.0.1:6553: read tcp 127.0.0.1:50714->127.0.0.1:6553: i/o timeout return } fmt.Println(rtt) fmt.Println(resp.Answer) }