Short answer: No, you cannot assume that the same name servers means the same origin due to shared hosting companies.
Longer answer: It depends on what you mean by
origin, but still by and large no. There are a few possible meanings of the phrase, so I'll briefly discuss a few scenarios.
- Origin: Some company or organization.
The case for these not being the same includes hosting companies. Both company a (
a.com) and company b (
b.com) can use the same hosting company c (
c.com). So it would be possible for both
b.com to have the same servers of
ns.c.com. However, they are still not associated with each other.
lookingforwardgivingback.com are both hosted with the same NS server, however are not associated with each other.
$ nslookup -type=NS canadianlacrosse.ca
canadianlacrosse.ca nameserver = ns34.domaincontrol.com
canadianlacrosse.ca nameserver = ns33.domaincontrol.com
$ nslookup -type=NS lookingforwardgivingback.com
lookingforwardgivingback.com nameserver = ns34.domaincontrol.com
lookingforwardgivingback.com nameserver = ns33.domaincontrol.com
- Origin: Same IP address
This also cannot be assumed, again due to shared hosting companies.
Using the example above again,
a.com could be hosted at IP address
b.com could be hosted at IP address
220.127.116.11. The same name server does not necessarily provide any context about whence the network traffic is coming.
Using the real-world examples from above:
$ nslookup -type=A canadianlacrosse.ca
$ nslookup -type=A lookingforwardgivingback.com
Note: It is possible for them to have the same IP address as well, for the same reason as above, shared hosting companies.
- Origin: Same server
Finally, we can't assume that the same name server has any bearing on if it is the same server even. This one you probably assumed, however I mention this due to the ambiguity of attempting to identify how hosting/name services work. We also can't rule out the fact that they are the same server either, at least not without a little bit of work going further.
What does it all mean?
So, name services are the glue used to connect people to services. As much as actual glue doesn't give you an indication to what it is holding together, neither do name services in general. You will to think critically about which name server you are using, and what name you are looking up.
While in some cases (like the example you provided) the same server host organizationally owned domains, it is not true in all cases.
Updated based on comments:
While DNS is flexible enough to not have any inherent ownerships as part of it's configuration, common convention allows you to make inferences based on usage.
So, an authoritative name server that is owned by an organization for its own domains can usually be relied on to identify common ownership. Your example shows that.
However, this only proves common ownership, it would be a fallacy (I think this is the correct use) to say it proves lack of ownership. That is to say, two domains without the same NS can still be owned by the same organization.