Original post

Hi,
I wanted to write something to see if a subdomain is reachable or not, something like brute force. What I’m doing right now is concatenating 2 strings, the domain, and the subdomain taken from a file, and doing a LookupIP but it really takes a lot of time even if I’m using goroutines.

this is what I was trying to do:

func check(a, subdom []string, b int, done chan int){

        for i := 0; i < len(a); i++ {
                _, error := net.LookupIP(a[i])
                if error == nil {
                        subdom = append(subdom, a[i])
                        fmt.Println(subdom)
                } 
        }

        done <- b
}

do you think that with dns req I can make it faster? How can I do that? It seems that there is no package in modules that allowes me to do that? Hope you help,
Thanks in advantage :slight_smile: