How to get local network domain name in Python?

Question

I have a script that is given a bunch of local IPv4 addresses in a local network. I can get the hostnames of those IPs in Python2.7 via:

socket.gethostbyaddr(IP)

However, these hostnames (if resolved) return as something of the form:

hostname.local.companyname.com

The only piece of information I'm interested in with this value is hostname. I would like to remove the local.companyname.com domain name from the fully qualified hostname. I could find the aspects of all resolved hostnames in common and then remove them that way, but I'm wondering if there is there any way to directly query the local domain itself?

(edit: this is running on Ubuntu)

Depending on the OS and network it might be better to properly set the hostname. — Klaus D., Jan 23 '19 at 11:02

score 3 · Accepted Answer · answered Jan 23 '19 at 12:27

3

For Default machine domain name Try:

import socket

def get_dns_domain():
    return socket.getfqdn().split('.', 1)[1]

print get_dns_domain()

answered Jan 23 '19 at 12:27

Anonymous

659
6
16

score 1 · Answer 2 · answered Jan 23 '19 at 13:12

Ubuntu likes to put your local unqualified hostname in /etc/hosts with a loopback IP address like this:

127.0.1.1   ubuntu-pc

which makes it difficult to get your real IP and domain.

One solution is to use this answer to get your real (not loopback) IP address, and look this IP up and use its domain:

import socket
s = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
s.connect(("8.8.8.8", 80))
myip = s.getsockname()[0]
s.close()
fqdn = socket.gethostbyaddr(myip)[0]
domain = fqdn.split('.', 1)[1]
print 'myip:', myip
print 'fqdn:', fqdn
print 'domain:', domain

Which outputs something similar to:

myip: 192.168.1.33
fqdn: fred-pc.my.domain
domain: my.domain

I already have IP addresses (given by network traffic). As I said in the question, I can get the domain name from `socket.gethostbyaddr(IP)`. I'm just trying to see if there are any other methods to exclusively get the domain, rather than parsing it out of the fully qualified domain name. — MikeFenton, Jan 24 '19 at 10:03

score 1 · Answer 3 · answered Jan 31 '19 at 14:11

1

>>> hostname = socket.gethostbyaddr(IP)[0].partition('.')[0]
>>> hostname
'myhost'

>>> hostname, domain = socket.gethostbyaddr(IP)[0].partition('.')[::2]
>>> hostname, domain
('myhost', 'here.example.com')

answered Jan 31 '19 at 14:11

Greg Mueller

506
3
7

How to get local network domain name in Python?

3 Answers3