Finding DNS and SMTP server ID's

I'm having the installation of new equipment thrust on me and some of the stuff is on the fringe of my knowledge of computer networking. One of the things it needs in the network setup are the primary and secondary DNS server IP's and the SMTP server name or IP.

When I go in to customers who are not computer literate and start asking for such things I'm usually met with blank stares. Often these are smaller companies who have no full or part-time IT departments. Usually their network was put together by the friend of a friend who isn't around to ask.

I can generally find a static IP for my device by doing 'ipconfig' from a C prompt to get and idea of their network range, and then pinging around 'till I get no response (if they're using DHCP). But is there a similar command that I can use to find the information I need for the DNS and SMTP servers?

Tanks, Rich

Reply to
Rich Piehl
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The domain name system (DNS) stores and associates many types of information with domain names, but most importantly, it translates domain names (computer hostnames) to IP addresses. It also lists mail exchange servers accepting e-mail for each domain. In providing a worldwide keyword-based redirection service, DNS is an essential component of contemporary Internet use.

Simple Mail Transfer Protocol (SMTP) is the de facto standard for e-mail transmissions across the Internet. Formally SMTP is defined in RFC 821 (STD 10) as amended by RFC 1123 (STD 3) chapter 5. The protocol used today is also known as ESMTP and defined in RFC 2821.

Your ISP (Internet Services Provider) runs these for you, so you can use both the primary and secondary DNS server IP addresses and the SMTP server name or IO provided by your ISP; this does not restricts you to run your though, but that could be an added overhead for small sites.

That's why their ISP's can make things easy and, or simple, even any local IT expert will ask these and, or other IP addresses from the ISP itself.

Is possible, but ISP do run these kinds of services as yet, better make call to their helpline.

Hope that helps,

Reply to
Balwinder S "bsd" Dheeman

The network range _is_ specified in the ipconfig output. If you don't know how to extract that from what ipconfig displays, you _shouldn't_ be doing this kind of work.A At least without more training. Demand that your employer send you to training, if he wants you to do this jobs

That aside --

DNS/SMTP information is always made available -- usually on-line, sometimes it takes a phone call -- by the provider of the Internet connectivity that the customer is using.

The other way to find out: "look at a machine where it is working", and copy those settings.

Note: if they're using DHCP, and it is properly set up, the DHCP server _should_ be providing the IP address to the client machine for the DNS server.

Outgoing SMTP servers are _frequently_ something very close to "mail.{provider}.com" Incoming mail servers are frequently something close to "pop.{provider}.com"

Many providers have a web-page for their customers, with all these configuration settings on them.

Reply to
Robert Bonomi

There's no need to talk down to me. I know what IPCONFIG does...and doesn't give.

Correct me if I'm wrong, but unless I have the DNS server ID's putting mail.[name].com won't do beans since my device has know what of finding what IP address mail.[name].com goes to. And my device doesn't do DHCP so it can't pull it from the DHCP server. So then I'm back to square one - sort of trying to track down someone at the ISP who might be able to help is there another way to determine the address of the DNS server for the network?

Take care, Rich

God bless the USA

Reply to
Rich Piehl

Bring along your laptop, plug it into the network, and see what DNS server the DHCP server provides. Then use that. If there is no DHCP server, look at the config of some other machine on the same network segment. Sheesh.

There is no standard for mail servers. If guessing obvious names doesn't work, most ISPs have web sites for their users with configuration info.

R's, John

Reply to
John L

Sorry, your own description of your activities says otherwise -- if you're having to ping random addresses to find the network range, as you said, then you _don't_ know.

Correct.

There are precisely TWO ways to find out where the DNS server(s) are. 1) look at a *working* machine 2) ask someone who knows.

It is a _very_ common question to ISP tech support.

Reply to
Robert Bonomi

BTW, on this I've conveyed this to my employer numerous times. The mindset is training time is not time spent in the field, plus I have to be paid while I'm in training. So the company is losing money twice while I'm in training. Doesn't matter that it takes me three times as long to do a job without training. Or that it makes the company look like Keystone cops.

Forgive me if I was misunderstood, but if I go into a network using DHCP and I need a static IP I have to be sure that the IP I select isn't already in use by some other device. Hence the need to do some pinging to find and unused addressed. If you know another way to find an unused IP address on a DHCP system with no IT management please enlighten me.

Exactly what I'm asking. On a working machine which is set to automatically get DNS server address how can I obtain what that address is?

So what your saying is that I ask the customer for their ISP tech support number when they aren't even 100% sure what ISP they have. Got it.

Thanks.

Take care, Rich

Reply to
Rich Piehl

Okay, I plug in my laptop and automatically get an IP address. That I get. What do I do to obtain the DNS server ID's from my laptop with the TCP/IP properties set to automatically obtain DNS server IP address?

This information was helpful. Thanks.

Take care, Rich

God bless the USA

Reply to
Rich Piehl

Um, once your laptop has gotten its address via DHCP, you look at the network setup to see what the DNS server is set to. The details vary from one operating system to another, but anyone with any familiarity with networking would surely know how to find this basic bit of info.

R's, John

Reply to
John L

If you're behind a typical packated router, the router has a web server you can log into from your laptop and see what the setup is. While you're at it, shrink the IP range it allocates by an address or two and use one of those for your device.

Actually, yes. Extracting enough info from the customer to solve the customer's problem is an important tech support skill.

R's, John

Reply to
John L

That's what I said in my OP...I'm at the outer edges of my network knowledge. I'm using Win XP. If I go to "network connection-TCP/IP properties" the 'obtain DNS server address automatically" is checked and the fields where the IP address are blank. Please tell me where I can obtain that information from my laptop?

Take care, Rich

God bless the USA

Reply to
Rich Piehl

Lots of snips because I jumped in late. See below

From what I gather you are installing a device at a customer location, who is using DHCP from an ISP. Your device does not do DHCP. You have pinged what you thought may be the IP range this customer is using to find an unused IP, so you can use it statically for your device. A problem here pops up because if you do not tell the dhcp server not to use that address, the dhcp server may try to use it causing an IP conflict. Are you sure the Customer does not have its own DHCP server, and is only getting one or two ip addresses from the ISP. In other words, does the customer have its own private network. As to finding out the DNS server, ipconfig /all has that info. So like the other guy said, go to another machine and do an ipconfig /all While you are on that machine check the email settings to get the snmp and pop config info.

Reply to
Dana

He is correct here. And sometimes you do have to do a little digging. They are paying someone for their internet service, so someone has to know who is getting paid for the internet service.

I also think you are behind a router here, and it makes sense to log into that router and obtain the info you need. And from the way you make this sound it may just be a linksys type router, which are not very complicated as far as the GUI is concerned. And yes you would want to shrink the DHCP pool so you can assign an address to you static device.

Reply to
Dana

Dana, thank you. This information is -exactly- what I have been looking for.

This isn't just a one time install. My company is selling these devices so I may encountering this scenario more than once.

Yes, it will be behind a router. Whether it will be Linksys, D Link, one those combo DSL or Cable modem/routers I can't say. I was looking for info to make all these scenarios easier.

Thanks.

Take care, Rich

God bless the USA

Reply to
Rich Piehl

In article , Rich Piehl wrote: : :That's what I said in my OP...I'm at the outer edges of my network :knowledge. I'm using Win XP. If I go to "network connection-TCP/IP :properties" the 'obtain DNS server address automatically" is checked and :the fields where the IP address are blank. Please tell me where I can :obtain that information from my laptop?

Something wrong with "ipconfig /all" ?

Reply to
Robert Nichols

My condolences. I'd advise you to look for a different employer. You, long-term, aren't going to be able to do a 'satisfactory' (to yourself, or to your employer) job in the environment you describe.

Again, you demonstrate that you "don't know what you don't know". Just because there is no response to a ping at a given address does *NOT* mean that it is safe to use for a staticly-addressed device. There is no guarantee that the DHCP server will not assign that address to another device within the next 3 minutes (or less).

You've got a *lot* more problems than that. You _don't_ have enough information, or knowledge, to intermix DHCP-assigned addresses and static addresses on the same LAN.

If you're installing into a DCHP-controlled environment, your device

*really* should be a DHCP client. If it requires a fixed address, then you handle that in the DHCP *server* configuration.

Get some training!

_WHERE_ does it get the DNS server address from?

Do you know how to look at the server configuration on _that_ machine, for what it hands out to clients?

Do you have the 'reference manual' for that box? Have you *read* it?

*WHO* do _they_ call when their connection goes out? *somebody* there knows how to handle that 'little' problem, don't they?

If that doesn't work, a competent professional knows how to find out what the 'public' IP address(es) are that the network uses to talk to the outside world.

And, how to find out who those addresses are allocated to.

And, how to find out where to contact that party.

I repeat my previous: If you don't know how to do this, you *shouldn't* be doing this kind of work. If your employer expects you to do this kind of work _without_ training, you should look for other employment,your performance will not be satisfying to yourself or to your employer.

Reply to
Robert Bonomi

You have a bigger problem. Even knowing the DNS servers, you can't just blindly choose an IP for your box because it seems to be vacant at that instant.

It could be in the DHCP pool. It could be an existing static assignment that off-line at that time. OR, it could be vacant, but the people running that subnet may later assign it; not knowing you appropriated it.

I had a PHB who put his new printer on the IP of the Samba server. It took me weeks to figure why the server was suddenly flakey.

Reply to
David Lesher

No, except I didn't know it existed until Dana informed me of that somewhere else in this thread.

Take care, Rich

God bless the USA

Reply to
Rich Piehl

I would not say that. He is smart enough to know when to ask for help. He is no different than a lot of IT types who think they know RF and networks just because they know the microsoft command line. I have seen more in house IT types screw the pooch way more than what is being described here.

That can also be said for a lot of IT types who think they know RF(radio/wireless) and networking. He knows enough to ask for help. No one enters a job without a learning curve.

This could be said for many IT departments where they expect a windows tech to be able to network and do wireless. Everyone has a learning curve.

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Reply to
Dana

"There's no need to talk down to me. I know what IPCONFIG does...and doesn't give."

I interpreted that to mean you were familiar with it. My mistake. Sorry.

Reply to
Robert Nichols

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