How to get ip Address from hostname?

Question

I have an node.js server application that needs to know the requested ip address in order to do some operation. The problem is that, when the user use /etc/hosts to register an Ip alias to access my server, the req.headers information on the server side shows the ip alias and not the ip requested.

I am using restify to serve my application, I already tried the req.connection but it is still no good.

I need that the javascript from my website knows what is actually the ip alias's ip address (pre-registered in the /etc/hosts) or that my node.js(restify) interprets the real ip_address requested and not the ip alias that the client uses.

Edit1: The main problem on getting the ip address requested on de server (nodejs) is that the requested for this cases is the ALIAS registered on the /etc/hosts. So it arrives at the server as just the named alias and not the ip (my server listens on multiple different IPs)

Short answer: you can't do that. – Jared Smith Aug 28 '19 at 15:12 — Jared Smith, Aug 28 '19 at 15:12

score 0 · Answer 1 · answered Aug 28 '19 at 15:40

0

Node JS DNS Documentation. https://nodejs.org/api/dns.html

or check the below link. How to resolve hostname to an ip address in node js

answered Aug 28 '19 at 15:40

Jayshree Rathod

77
6

I have attached an image for check that, if it helps mark is as accepted answer and give an upvote check this link https://jlericson.com/2016/07/13/QA_economics.html – ANIK ISLAM SHOJIB Aug 28 '19 at 16:21

ANIK ISLAM SHOJIB · Answer 2 · 2019-08-28T16:19:53.137

0

you can check here https://nodejs.org/api/dns.html#dns_dnspromises_lookup_hostname_options

also try

const dns = require('dns');
const dnsPromises = dns.promises;
const options = {
  family: 6,
  hints: dns.ADDRCONFIG | dns.V4MAPPED,
};

dnsPromises.lookup('example.com', options).then((result) => {
  console.log('address: %j family: IPv%s', result.address, result.family);
  // address: "2606:2800:220:1:248:1893:25c8:1946" family: IPv6
});

// When options.all is true, the result will be an Array.
options.all = true;
dnsPromises.lookup('example.com', options).then((result) => {
  console.log('addresses: %j', result);
  // addresses: [{"address":"2606:2800:220:1:248:1893:25c8:1946","family":6}]
});

check this output section

edited Aug 28 '19 at 16:19

answered Aug 28 '19 at 15:47

ANIK ISLAM SHOJIB

3,002
1
27
36

I dont think I can use nodejs dns because the /etc/hosts file is on my client side, so the server side does not know about it – Lucas Rebello Aug 28 '19 at 16:06
dnsPromises.lookup will look up the internet for this domain nothing related to client-side or server-side – ANIK ISLAM SHOJIB Aug 28 '19 at 16:16
The problem is that it is not a domain that can be accessed anywhere, it is only acessible on my local network – Lucas Rebello Aug 28 '19 at 16:28
brother if you host it in a server it will work as usual you can try. – ANIK ISLAM SHOJIB Aug 28 '19 at 16:34

How to get ip Address from hostname?

2 Answers2