# Reverse DNS Look Up
**URL:** https://discourse.nodered.org/t/reverse-dns-look-up/22807
**Category:** General
**Created:** [8 March 2020 18:22 UTC](https://discourse.nodered.org/t/reverse-dns-look-up/22807 "2020-03-08T18:22:30Z")
**Posts on this page:** 6
**Page:** 1
### Author:  [@nodecentral](https://discourse.nodered.org/u/nodecentral)
#### Post date: [8 March 2020 18:22 UTC](https://discourse.nodered.org/t/reverse-dns-look-up/22807/1 "2020-03-08T18:22:31Z")
Hi
I’m trying to get the IP address of a domain name, so I can add the IP to my firewall but I can’t seem to get the dns node to work - [node-red-contrib-dns (node) - Node-RED](https://flows.nodered.org/node/node-red-contrib-dns)
Is anyone using this successfully for reverse look ups ?
I’m simple trying to send the domain name (e.g [www.google.com](http://www.google.com)) via an inject node to the dns node (set to Reverse) to see if it can return the IP address via debug node ?
I’ve tried variations of the domain name, http:/www.google.com, [www.google.com](http://www.google.com), [google.com](http://google.com) - it all I seem to get in return is this error, and nothing reaches the debug node
> 08/03/2020, 18:21:12
> msg : error
> "Error: getHostByAddr EINVAL"
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### Author:  [@techraf](https://discourse.nodered.org/u/techraf)
#### Post date: [8 March 2020 19:20 UTC](https://discourse.nodered.org/t/reverse-dns-look-up/22807/2 "2020-03-08T19:20:55Z")
> [@nodecentral](#):
>
> I’m simple trying to send the domain name (e.g [www.google.com](http://www.google.com)) via an inject node to the dns node (set to Reverse)
That makes no sense, so you get the error.
`www.google.com` is not an [`.in-addr.arpa`](https://en.wikipedia.org/wiki/Reverse_DNS_lookup#IPv4_reverse_resolution) address.
Either you should do a simple lookup, or rethink what you want to achieve.
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### Author:  [@bakman2](https://discourse.nodered.org/u/bakman2)
#### Post date: [8 March 2020 20:00 UTC](https://discourse.nodered.org/t/reverse-dns-look-up/22807/3 "2020-03-08T20:00:25Z")
> [@techraf](#):
>
> Either you should do a simple lookup, or rethink what you want to achieve.
Exactly this.
domain -\> exec node: nslookup -\> output. Or use `dig +short google.com` instead.
```auto
[{"id":"aa5d9ffd.ef58b8","type":"inject","z":"a8be5bbf.2423a","name":"google.com","topic":"","payload":"google.com","payloadType":"str","repeat":"","crontab":"","once":false,"onceDelay":0.1,"x":286,"y":336,"wires":[["5c0eeb15.cedd2c"]]},{"id":"5c0eeb15.cedd2c","type":"exec","z":"a8be5bbf.2423a","command":"nslookup","addpay":true,"append":"","useSpawn":"false","timer":"","oldrc":false,"name":"","x":442,"y":336,"wires":[["cb73c5b5.fca318"],[],[]]},{"id":"cb73c5b5.fca318","type":"debug","z":"a8be5bbf.2423a","name":"","active":true,"tosidebar":true,"console":false,"tostatus":false,"complete":"true","targetType":"full","x":602,"y":336,"wires":[]}]
```
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### Author:  [@techraf](https://discourse.nodered.org/u/techraf)
#### Post date: [8 March 2020 20:19 UTC](https://discourse.nodered.org/t/reverse-dns-look-up/22807/4 "2020-03-08T20:19:36Z")
I'm not sure what you wanted to say in your reply.
@nodecentral needs to select "lookup" instead of "reverse" in the `dns` node.
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### Author:  [@nodecentral](https://discourse.nodered.org/u/nodecentral)
#### Post date: [9 March 2020 18:55 UTC](https://discourse.nodered.org/t/reverse-dns-look-up/22807/5 "2020-03-09T18:55:18Z")
Thanks all, the 'lookup' option worked a treat !
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### Author:  [@system](https://discourse.nodered.org/u/system)
#### Post date: [23 March 2020 18:55 UTC](https://discourse.nodered.org/t/reverse-dns-look-up/22807/6 "2020-03-23T18:55:19Z")
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