Brian Wilson

What kind of entry do you use to make DNS point toward a specific port?

If anyone knows, thanks, and you are a huger nerd than I am.

Toolmaster

ECpunk -

Well, technically speaking, it'd be a SRV record.

Bind 8.2.3+ and Microsoft DNS support SRV records.

In earlier versions of BIND, and also Microsoft DNS, there was no support for this.

The record contains the specific port a service is advertised on.

If this isn't what you're looking for, let me know and I can try to help.

What exactly are you trying to do?

HTH!

TomH

Don't know why you would do this either, but can't you enter you DNS entries in the TCP properties with the IP address followed by the specific port, aka 192.168.121.1:8080

Toolmaster

Tom -

You can point a browser, or other "tcp/ip" type communication utility using your format of x.y.z.a ort# .

But I have a feeling he's trying to do something else, like redirect a webpage to a different port on the DNS side. (Which really can't be done that easily.)

TomH

Toolmaster, I think that can be done realtively easily. Most firewalls use NAT to translate public to private addresses. So when a user comes in on standard port 80, the firewall can translate/redirect that request to another IP and port designation on the inside.

Also many of today's web servers can perform redirection, but it would require one web server listening on port 80 to redirect the request to a second web server handling the other port (8080).

ecpunk, what are you really trying to do?

Toolmaster

Tom -

You're right - firewalls, routers, and web servers all can do this... But to get DNS itself to do it makes it a lot harder.

Jay

mideastmafia

ECPUNK..

if you are doing it as an IP block segment, you can specify it as x.x.x.x:80

assuming that the x's are your IP and the 80 is your port.

example: 24.94.18.231:80

PORT 80


SHAUN

Sasha

ECPunk,

DNS - Domain Name Server (Service) is designed to convert a host IP (Internet Protocol) address in form of xxx.xxx.xxx.xxx into a computer name such as <a href="http://www.yahoo.com" target="_blank">www.yahoo.com</a> and vice versa. On many OS (Operating Systems) it is implemented as a database (mostly a text file /etc/hosts) and a server running on a particular port. When you connect to it, you ask for a name and it looks it up and converts it into IP address. The way it converts it, is it looks into its own local file /etc/hosts for unix-like OS, or c:\windows\hosts or c:\windows\networks on Win9x machines. If an entry is present, it returns an IP address for that host name, otherwise it connects to the next known DNS server (also configured in local OS), and so on until the name is resolved.

DNS does not have anything to do with ports. Ports are network services. For example echo service is on port 7, telnet is on port 23, SSH is on port 22, HTTP is on port 80. Port is a number between 0 - 65535, that low level network software interprets as a file decriptior. On unix like machines you can look up available services in /etc/services file. Win9x machines don't provide any services at all.

If you describe a goal you are trying to achieve I may be able to come up with instructions on how to do it.


Sasha
Senior Software Engineer

Brian Wilson

Thank you for all the answers, but not mine.


I usually use DNS for a direct name to address translation. I've never had a class and don't fool with it much more than adding new host's and things of that nature. The AF would probably get mad if I brought the base down because I was "trying to figure it out!!!"

Straight up here it is:

I want to be able to type an address in my browser and bring up Cisco Works, which uses port 17!!. I don't want to have to keep typing the name of the <a href="http://server:" target="_blank">http://server:</a> port like I have to now. I also can't expect the idiots that I work with to remember port numbers.

Not a complicated question...

ha ha, just figured out that you can't type server : port or it looks like this server ort

Brian Wilson

BTW Sasha - There are 65536 ports, and if you want to be real crazy, then twice as many as that(TCP and UDP). The well known ports are from 0 through 1023. The registered ports are from 1024 through 49151, and bringing up the rear are the private ports, which are from 49152 through 65535.
Hey, thanks for the refresher anyway!
and doom is on port 666.

Toolmaster

If it's only on a couple systems, use a hosts file with the x.y.z.a ort set for the name you specify.

If it's more than a couple systems, use a redirect. Setup a web server and create a base page on port 80 (HTTP) that redirects (or you can just use the web server's port redirection of course) to send them to 17.

What OS you using? I could give exact configs if you tell me that...

Thanks!

Brian Wilson

Good idea... but a problem.

With the AF, you can't just set stuff up like that. It has to be a certain way.

It will just be one system, though. I'm not to up on redirects and things. I'm an infrastructure guy and don't get too much into webpages. We run win2k of course. Doesn't everyone???

Jonathan Martini

If its just on one system, why not set up a web page that just has a link to the server ort.

You can just set it up as a redirecting web page, without the usual 5-10 second timeout.

It doesn't even have to be on a server if by 'one system' you mean literally one machine.

Sometimes the simplest answer will work.

Cheers.

Jason-85944

Why can't you use the hosts file? It is in the Winnt\system32\drivers\etc folder...

a sample entry would be as follows:

192.1.1.120 <a href="http://www.blahblahblah.com:8080" target="_blank">www.blahblahblah.com:8080</a>

Always HTH!

Jason Chance, MCSE,CNA,A+

Jonathan Martini

Just realized that a : followed by a 'p' is a Graemlin. <img src="graemlins/roflmao.gif" border="0" alt="[hiha]" />