Discussion:
How to find IP address of a machine on network?
(too old to reply)
Chris G
2009-01-16 17:28:51 UTC
Permalink
I have just installed ubuntu onto a machine and have connected it to
my LAN. The router provides DHCP and the new machine is up and
running on the network.

How do I connect *to* the machine? I need to know its IP address and,
as there are a few devices which get their address by DHCP it's not at
all obvious what the machine's address is.

Eventually I will probably give it a fixed address (for this reason
among others).
--
Chris Green
Wade Smart
2009-01-16 17:34:11 UTC
Permalink
Post by Chris G
I have just installed ubuntu onto a machine and have connected it to
my LAN. The router provides DHCP and the new machine is up and
running on the network.
How do I connect *to* the machine? I need to know its IP address and,
as there are a few devices which get their address by DHCP it's not at
all obvious what the machine's address is.
Eventually I will probably give it a fixed address (for this reason
among others).
20090116 1133 GMT-5

System > Network Toos > Devices Tab, select eth0 and it will tell you
the ip of that machine.

Wade
--
Registered Linux User: #480675
Linux since June 2005
Chris G
2009-01-16 18:46:39 UTC
Permalink
Post by Wade Smart
Post by Chris G
I have just installed ubuntu onto a machine and have connected it to
my LAN. The router provides DHCP and the new machine is up and
running on the network.
How do I connect *to* the machine? I need to know its IP address and,
as there are a few devices which get their address by DHCP it's not at
all obvious what the machine's address is.
Eventually I will probably give it a fixed address (for this reason
among others).
20090116 1133 GMT-5
System > Network Toos > Devices Tab, select eth0 and it will tell you
the ip of that machine.
OK, thanks, not much use from the other end though is it!
--
Chris Green
Nils Kassube
2009-01-16 19:08:26 UTC
Permalink
Post by Chris G
Post by Wade Smart
Post by Chris G
How do I connect *to* the machine? I need to know its IP address
and, as there are a few devices which get their address by DHCP
it's not at all obvious what the machine's address is.
System > Network Toos > Devices Tab, select eth0 and it will tell you
the ip of that machine.
OK, thanks, not much use from the other end though is it!
Well, as long as you don't install any servers you can't connect. I
suppose you want to install the package "openssh-server" and then you can
use ssh to connect to the machine.


Nils
Chris G
2009-01-16 19:11:48 UTC
Permalink
Post by Nils Kassube
Post by Chris G
Post by Wade Smart
Post by Chris G
How do I connect *to* the machine? I need to know its IP address
and, as there are a few devices which get their address by DHCP
it's not at all obvious what the machine's address is.
System > Network Toos > Devices Tab, select eth0 and it will tell you
the ip of that machine.
OK, thanks, not much use from the other end though is it!
Well, as long as you don't install any servers you can't connect. I
suppose you want to install the package "openssh-server" and then you can
use ssh to connect to the machine.
Quite right, so I have a machine that runs sshd and I want to connect
to it and I know it's on the LAN but not its IP address.
--
Chris Green
Thomas Kaiser
2009-01-16 19:27:43 UTC
Permalink
Post by Chris G
Post by Nils Kassube
Post by Chris G
Post by Wade Smart
Post by Chris G
How do I connect *to* the machine? I need to know its IP address
and, as there are a few devices which get their address by DHCP
it's not at all obvious what the machine's address is.
System > Network Toos > Devices Tab, select eth0 and it will tell you
the ip of that machine.
OK, thanks, not much use from the other end though is it!
Well, as long as you don't install any servers you can't connect. I
suppose you want to install the package "openssh-server" and then you can
use ssh to connect to the machine.
Quite right, so I have a machine that runs sshd and I want to connect
to it and I know it's on the LAN but not its IP address.
You can use nmap in a terminal to scan the network for open ports.

thomas at AMD64:~$ nmap 192.168.0.*

Starting Nmap 4.53 ( http://insecure.org ) at 2009-01-16 20:25 CET
Interesting ports on 192.168.0.1:
Not shown: 1711 filtered ports
PORT STATE SERVICE
23/tcp closed telnet
80/tcp open http
8080/tcp closed http-proxy

Interesting ports on 192.168.0.2:
Not shown: 1709 closed ports
PORT STATE SERVICE
22/tcp open ssh
139/tcp open netbios-ssn
143/tcp open imap
445/tcp open microsoft-ds
993/tcp open imaps

Interesting ports on 192.168.0.3:
Not shown: 1713 closed ports
PORT STATE SERVICE
80/tcp open http

Interesting ports on 192.168.0.4:
Not shown: 1709 closed ports
PORT STATE SERVICE
21/tcp open ftp
22/tcp open ssh
23/tcp open telnet
80/tcp open http
31337/tcp open Elite

All 1714 scanned ports on 192.168.0.11 are closed

All 1714 scanned ports on 192.168.0.13 are closed

Interesting ports on 192.168.0.16:
Not shown: 1711 closed ports
PORT STATE SERVICE
22/tcp open ssh
80/tcp open http
5432/tcp open postgres

Nmap done: 256 IP addresses (7 hosts up) scanned in 22.775 seconds


Regards, Thomas
Charles Darwin
2009-01-16 20:11:20 UTC
Permalink
Post by Thomas Kaiser
You can use nmap in a terminal to scan the network for open ports.
I used to use nmap but then I found this on my mac (much faster for
what we're trying to do here):

dns-sd -B _ssh._tcp .

This works with Zeroconf and (from man dns-sd's) supposedly comes
with BSD.
Now here are my questions:
1. Is there something like this unique to *nix?
2. How do you run umap light so that it runs as fast as dns-sd (for
what we want here) or possibly tops it?
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Chris Mohler
2009-01-16 20:32:23 UTC
Permalink
2. How do you run umap light so that it runs as fast as dns-sd (for what we
want here) or possibly tops it?
This is pretty fast:
sudo nmap -sP 10.0.1.*

(-sP - means "Ping Scan")

Chris
Charles Darwin
2009-01-16 20:48:53 UTC
Permalink
Post by Chris Mohler
sudo nmap -sP 10.0.1.*
That was nice but still `dns-sd -B _ssh._tcp .` is faster. How do you
tell nmap to only look for those that broadcast ssh?
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Chris Mohler
2009-01-16 21:07:04 UTC
Permalink
Post by Chris Mohler
sudo nmap -sP 10.0.1.*
That was nice but still `dns-sd -B _ssh._tcp .` is faster. How do you tell
nmap to only look for those that broadcast ssh?
sudo nmap -p 22 10.0.1.*
[sudo] password for XXXXXXX:

Starting Nmap 4.62 ( http://nmap.org ) at 2009-01-16 15:05 CST
Interesting ports on X.X.X.X:
PORT STATE SERVICE
22/tcp closed ssh
MAC Address: XXXXXXXXXXX (Apple Computer)

Interesting ports on X.X.X.X:
PORT STATE SERVICE
22/tcp closed ssh

Nmap done: 256 IP addresses (2 hosts up) scanned in 5.686 seconds

Chris
NoOp
2009-01-16 21:44:29 UTC
Permalink
Post by Chris Mohler
Post by Chris Mohler
sudo nmap -sP 10.0.1.*
That was nice but still `dns-sd -B _ssh._tcp .` is faster. How do you tell
nmap to only look for those that broadcast ssh?
sudo nmap -p 22 10.0.1.*
Starting Nmap 4.62 ( http://nmap.org ) at 2009-01-16 15:05 CST
PORT STATE SERVICE
22/tcp closed ssh
MAC Address: XXXXXXXXXXX (Apple Computer)
PORT STATE SERVICE
22/tcp closed ssh
Nmap done: 256 IP addresses (2 hosts up) scanned in 5.686 seconds
Chris
I installed zenmap (use the intrepid version if you are using hardy as
the hardy version doesn't include an .desktop file for the
Applications|Internet menu):
http://packages.ubuntu.com/intrepid/zenmap
[installs just fine on hardy]
and found it pretty useful/interesting.

You can enter commands as from the CLI and save as a profile addition.
For example in answer to Charles Darwin's question, I just created a
command profile to scan for ssh and:

nmap -p22 x.x.x.*
========
Starting Nmap 4.53 ( http://insecure.org ) at 2009-01-16 13:37 PST
Interesting ports on x.x.x.x:
PORT STATE SERVICE
22/tcp closed ssh
MAC Address: x:x:x:x:x:x (Cisco-Linksys)

Interesting ports on x.x.x.x:
PORT STATE SERVICE
22/tcp open ssh

Interesting ports on <systemname> (x.x.x.x):
PORT STATE SERVICE
22/tcp filtered ssh
MAC Address: x:x:x:x:x:x (Intel)

Interesting ports on <systemname> (x.x.x.x):
PORT STATE SERVICE
22/tcp closed ssh
MAC Address: x:x:x:x:x:x (Intel)

Interesting ports on <systemname> (x.x.x.x):
PORT STATE SERVICE
22/tcp open ssh
MAC Address: x:x:x:x:x:x (Asustek Computer)

Interesting ports on x.x.x.x:
PORT STATE SERVICE
22/tcp filtered ssh
MAC Address: x:x:x:x:x:x (Netgear)

Nmap done: 256 IP addresses (6 hosts up) scanned in 3.001 seconds
========

You can even save the scans, open a saved scan etc. Pretty nice GUI overall.

http://nmap.org/book/zenmap.html
Brian McKee
2009-01-16 22:20:23 UTC
Permalink
Post by NoOp
I installed zenmap (use the intrepid version if you are using hardy as
the hardy version doesn't include an .desktop file for the
http://packages.ubuntu.com/intrepid/zenmap
[installs just fine on hardy]
and found it pretty useful/interesting.
The topo map is kinda cool and useful...

http://nmap.org/book/zenmap-results.html#zenmap-tab-topology

Brian
Chris Mohler
2009-01-16 22:56:54 UTC
Permalink
Post by Brian McKee
Post by NoOp
I installed zenmap (use the intrepid version if you are using hardy as
the hardy version doesn't include an .desktop file for the
http://packages.ubuntu.com/intrepid/zenmap
[installs just fine on hardy]
and found it pretty useful/interesting.
The topo map is kinda cool and useful...
http://nmap.org/book/zenmap-results.html#zenmap-tab-topology
Hmm - the version of zenmap in the repos (intrepid) is 4.72 - the topo
map was added in 4.75. Latest stable is 4.76...

Chris
Chris Mohler
2009-01-16 23:05:18 UTC
Permalink
Post by Chris Mohler
Post by Brian McKee
Post by NoOp
I installed zenmap (use the intrepid version if you are using hardy as
the hardy version doesn't include an .desktop file for the
http://packages.ubuntu.com/intrepid/zenmap
[installs just fine on hardy]
and found it pretty useful/interesting.
The topo map is kinda cool and useful...
http://nmap.org/book/zenmap-results.html#zenmap-tab-topology
Hmm - the version of zenmap in the repos (intrepid) is 4.72 - the topo
map was added in 4.75. Latest stable is 4.76...
OK, it's a python package so I was able to run alien on the latest RPM
and get a deb file - no problems thus far, and the topo tab is pretty
neat...

Chris
NoOp
2009-01-16 23:54:36 UTC
Permalink
Post by Chris Mohler
Post by Chris Mohler
Hmm - the version of zenmap in the repos (intrepid) is 4.72 - the topo
map was added in 4.75. Latest stable is 4.76...
OK, it's a python package so I was able to run alien on the latest RPM
and get a deb file - no problems thus far, and the topo tab is pretty
neat...
Chris
Cool! You uninstalled the repo's version first I presume?
Chris Mohler
2009-01-17 00:08:39 UTC
Permalink
Post by NoOp
Post by Chris Mohler
Post by Chris Mohler
Hmm - the version of zenmap in the repos (intrepid) is 4.72 - the topo
map was added in 4.75. Latest stable is 4.76...
OK, it's a python package so I was able to run alien on the latest RPM
and get a deb file - no problems thus far, and the topo tab is pretty
neat...
Chris
Cool! You uninstalled the repo's version first I presume?
Nah - I just let gdebi lecture me about how I should prefer the
version in the repo ;) I wanted to test whether or not it would
upgrade properly (which it did). As long as alien gets the version
right during the conversion, that seems to work just fine.

Chris
NoOp
2009-01-17 00:49:18 UTC
Permalink
Post by Chris Mohler
Post by NoOp
Post by Chris Mohler
Post by Chris Mohler
Hmm - the version of zenmap in the repos (intrepid) is 4.72 - the topo
map was added in 4.75. Latest stable is 4.76...
OK, it's a python package so I was able to run alien on the latest RPM
and get a deb file - no problems thus far, and the topo tab is pretty
neat...
Chris
Cool! You uninstalled the repo's version first I presume?
Nah - I just let gdebi lecture me about how I should prefer the
version in the repo ;) I wanted to test whether or not it would
upgrade properly (which it did). As long as alien gets the version
right during the conversion, that seems to work just fine.
Chris
I found that the 4.76-1 (nmap and zenmap) is considerably better than
the repo versions. Not only the addition of topology, but discovery
details are better as well. Good catch on the rpm's :-)
Derek Broughton
2009-01-17 01:00:19 UTC
Permalink
Post by NoOp
Post by Chris Mohler
Post by Chris Mohler
Hmm - the version of zenmap in the repos (intrepid) is 4.72 - the topo
map was added in 4.75. Latest stable is 4.76...
OK, it's a python package so I was able to run alien on the latest RPM
and get a deb file - no problems thus far, and the topo tab is pretty
neat...
Chris
Cool! You uninstalled the repo's version first I presume?
Shouldn't be necessary - alien creates a deb package which supercedes the
current Ubuntu package, and a later Ubuntu package will superced the alien'd
package.
NoOp
2009-01-17 01:52:33 UTC
Permalink
Post by Derek Broughton
Post by NoOp
Cool! You uninstalled the repo's version first I presume?
Shouldn't be necessary - alien creates a deb package which supercedes the
current Ubuntu package, and a later Ubuntu package will superced the alien'd
package.
Yep... 4.76-1 works well after using alien. Interesting that the repo
nstat version, when given the following command:

$ nmap -T Aggressive -A -v 192.168.2.*

shows (obfuscation apparent):

Host 192.168.2.XXX appears to be up ... good.
Interesting ports on 192.168.2.XXX:
Not shown: 1712 closed ports
PORT STATE SERVICE VERSION
139/tcp open netbios-ssn Samba smbd 3.X (workgroup: MSHOME)
445/tcp open netbios-ssn Samba smbd 3.X (workgroup: MSHOME)
5900/tcp open vnc VNC (protocol 3.7)

The 4.76-1 version shows:

Host <hostname> (192.168.2.XXX) appears to be up ... good.
Interesting ports on <hostname> (192.168.2.XXX):
Not shown: 996 closed ports
PORT STATE SERVICE VERSION
139/tcp open netbios-ssn Samba smbd 3.X (workgroup: MSHOME)
445/tcp open netbios-ssn Samba smbd 3.X (workgroup: MSHOME)
5900/tcp open vnc VNC (protocol 3.7)
16001/tcp open tcpwrapped

Host script results:
|_ NBSTAT: NetBIOS name: <hostname>, NetBIOS MAC: X:X:X:X:X:X
| Discover OS Version over NetBIOS and SMB: Unix
|_ Discover system time over SMB: 2009-01-16 17:02:58 UTC-8

So the newer version adds some nice details.
Karl F. Larsen
2009-01-17 02:21:09 UTC
Permalink
Post by NoOp
Post by Derek Broughton
Post by NoOp
Cool! You uninstalled the repo's version first I presume?
Shouldn't be necessary - alien creates a deb package which supercedes the
current Ubuntu package, and a later Ubuntu package will superced the alien'd
package.
Yep... 4.76-1 works well after using alien. Interesting that the repo
$ nmap -T Aggressive -A -v 192.168.2.*
Host 192.168.2.XXX appears to be up ... good.
Not shown: 1712 closed ports
PORT STATE SERVICE VERSION
139/tcp open netbios-ssn Samba smbd 3.X (workgroup: MSHOME)
445/tcp open netbios-ssn Samba smbd 3.X (workgroup: MSHOME)
5900/tcp open vnc VNC (protocol 3.7)
Host <hostname> (192.168.2.XXX) appears to be up ... good.
Not shown: 996 closed ports
PORT STATE SERVICE VERSION
139/tcp open netbios-ssn Samba smbd 3.X (workgroup: MSHOME)
445/tcp open netbios-ssn Samba smbd 3.X (workgroup: MSHOME)
5900/tcp open vnc VNC (protocol 3.7)
16001/tcp open tcpwrapped
|_ NBSTAT: NetBIOS name: <hostname>, NetBIOS MAC: X:X:X:X:X:X
| Discover OS Version over NetBIOS and SMB: Unix
|_ Discover system time over SMB: 2009-01-16 17:02:58 UTC-8
So the newer version adds some nice details.
You do not seem to have the actual address of your Internet. All the
192.168.x.x are sub IP to the various users. I have an ActionTec DSL
modem and router. To get my real IP address I got to http://192.168.0.1
and it has a page that tells me all about it. I print that page and it
is all there.

This works on most small and some quite big routers. My Real IP is
216.31.x.x which changes if I turn off. But I stay on for many days and
it's good for that period. I can ping my IP and it is quite fast.



Karl
--
Karl F. Larsen, AKA K5DI
Linux User
#450462 http://counter.li.org.
PGP 4208 4D6E 595F 22B9 FF1C ECB6 4A3C 2C54 FE23 53A7
NoOp
2009-01-17 02:47:20 UTC
Permalink
Post by Karl F. Larsen
You do not seem to have the actual address of your Internet. All the
192.168.x.x are sub IP to the various users. I have an ActionTec DSL
modem and router. To get my real IP address I got to http://192.168.0.1
and it has a page that tells me all about it. I print that page and it
is all there.
This works on most small and some quite big routers. My Real IP is
216.31.x.x which changes if I turn off. But I stay on for many days and
it's good for that period. I can ping my IP and it is quite fast.
I don't need it for this scan. If I need my Internet IP I simply check
my router. If I need a customer to tell me his/her internet IP I simply
have them go to http://whatsmyip.org/.

Besides, if I go to http://192.168.0.1 it won't tell me anything. My DSL
modem is set to bridge mode and my lans are run on different subnets
than 192.168.0.x. The _only_ way that I can connect to
http://192.168.0.1 from a browser is if I reconfigure a machine to be on
the 192.168.0.x network. In your case your machine is configured for
192.168.0.4 so you are on the same subnet as your DSL modem; hence you
can http://192.168.0.1 and see the modem's web interface.
Karl F. Larsen
2009-01-17 12:40:55 UTC
Permalink
Post by NoOp
Post by Karl F. Larsen
You do not seem to have the actual address of your Internet. All the
192.168.x.x are sub IP to the various users. I have an ActionTec DSL
modem and router. To get my real IP address I got to http://192.168.0.1
and it has a page that tells me all about it. I print that page and it
is all there.
This works on most small and some quite big routers. My Real IP is
216.31.x.x which changes if I turn off. But I stay on for many days and
it's good for that period. I can ping my IP and it is quite fast.
I don't need it for this scan. If I need my Internet IP I simply check
my router. If I need a customer to tell me his/her internet IP I simply
have them go to http://whatsmyip.org/.
Besides, if I go to http://192.168.0.1 it won't tell me anything. My DSL
modem is set to bridge mode and my lans are run on different subnets
than 192.168.0.x. The _only_ way that I can connect to
http://192.168.0.1 from a browser is if I reconfigure a machine to be on
the 192.168.0.x network. In your case your machine is configured for
192.168.0.4 so you are on the same subnet as your DSL modem; hence you
can http://192.168.0.1 and see the modem's web interface.
I was all messed up then. I really do not know what the question is.
Looking at the question he wants the IP address of a machine that is
working in a network. Well if it's working it must be done right and you
can just go to the machine and do a ifconfig and know all about it on
the machine in question.

I think he wants to do networking from a remote location. This is
like the questions I got in Collage where your inside the core of a big
transformer and you have certain tools like a amp meter and a coil of
wire. You calculate the details of the big transformer :-)

My solution was to get out of the room and read the information
plate on the big transformer.

Karl
--
Karl F. Larsen, AKA K5DI
Linux User
#450462 http://counter.li.org.
PGP 4208 4D6E 595F 22B9 FF1C ECB6 4A3C 2C54 FE23 53A7
Chris G
2009-01-17 17:05:13 UTC
Permalink
Post by Karl F. Larsen
Post by NoOp
Post by Karl F. Larsen
You do not seem to have the actual address of your Internet. All the
192.168.x.x are sub IP to the various users. I have an ActionTec DSL
modem and router. To get my real IP address I got to http://192.168.0.1
and it has a page that tells me all about it. I print that page and it
is all there.
This works on most small and some quite big routers. My Real IP is
216.31.x.x which changes if I turn off. But I stay on for many days and
it's good for that period. I can ping my IP and it is quite fast.
I don't need it for this scan. If I need my Internet IP I simply check
my router. If I need a customer to tell me his/her internet IP I simply
have them go to http://whatsmyip.org/.
Besides, if I go to http://192.168.0.1 it won't tell me anything. My DSL
modem is set to bridge mode and my lans are run on different subnets
than 192.168.0.x. The _only_ way that I can connect to
http://192.168.0.1 from a browser is if I reconfigure a machine to be on
the 192.168.0.x network. In your case your machine is configured for
192.168.0.4 so you are on the same subnet as your DSL modem; hence you
can http://192.168.0.1 and see the modem's web interface.
I was all messed up then. I really do not know what the question is.
Looking at the question he wants the IP address of a machine that is
working in a network. Well if it's working it must be done right and you
can just go to the machine and do a ifconfig and know all about it on
the machine in question.
I think he wants to do networking from a remote location. This is
like the questions I got in Collage where your inside the core of a big
transformer and you have certain tools like a amp meter and a coil of
wire. You calculate the details of the big transformer :-)
My solution was to get out of the room and read the information
plate on the big transformer.
Quite right, your "go and look at it" solution is probably the easiest
in my situation. ;-)
--
Chris Green
NoOp
2009-01-18 02:06:34 UTC
Permalink
[snip]
Post by Chris G
Post by Karl F. Larsen
My solution was to get out of the room and read the information
plate on the big transformer.
Quite right, your "go and look at it" solution is probably the easiest
in my situation. ;-)
I reckon that it doesn't really matter to you anyway as you've not
bothered to respond to any other suggestions provided in this thread.

Folks tried to assist you with multiple responses/solutions, and yet
your final response is to 'go and look at it'? Good luck with any
futher questions you have here as I'll not bother reading them.
Matthew Flaschen
2009-01-19 02:32:14 UTC
Permalink
Post by Chris G
Post by Karl F. Larsen
My solution was to get out of the room and read the information
plate on the big transformer.
Quite right, your "go and look at it" solution is probably the easiest
in my situation. ;-)
True. :)

Matt Flaschen

Chris Mohler
2009-01-17 02:54:08 UTC
Permalink
Post by Karl F. Larsen
You do not seem to have the actual address of your Internet.
All your internet are belong to us.

Chris
Derek Broughton
2009-01-17 03:48:34 UTC
Permalink
Post by Karl F. Larsen
Post by NoOp
Yep... 4.76-1 works well after using alien. Interesting that the repo
$ nmap -T Aggressive -A -v 192.168.2.*
??
Post by Karl F. Larsen
Post by NoOp
Host 192.168.2.XXX appears to be up ... good.
...
Post by Karl F. Larsen
Post by NoOp
Host <hostname> (192.168.2.XXX) appears to be up ... good.
"Obfuscation apparent" because it isn't showing hostnames? Are you sure
that's not just a change in default options? istr, that there are three
options - to always show hostnames, never show hostnames, and something in
between, so perhaps the default has become "always".
Post by Karl F. Larsen
You do not seem to have the actual address of your Internet. All the
192.168.x.x are sub IP to the various users.
Er, yes - and he explained that, earlier. You don't want to be using nmap
on addresses, because people think you're hacking them.
Post by Karl F. Larsen
I have an ActionTec DSL
modem and router. To get my real IP address I got to http://192.168.0.1
and it has a page that tells me all about it.
That may or may not work. Certainly wouldn't work for me - since that's not
my router's internal address. There are any number of pages on the
Internet that will tell you your Internet address.

In any case, it's not what the OP was looking for.
Matthew Flaschen
2009-01-17 04:09:08 UTC
Permalink
Post by Derek Broughton
Post by NoOp
Yep... 4.76-1 works well after using alien. Interesting that the repo
$ nmap -T Aggressive -A -v 192.168.2.*
??
Post by NoOp
Host 192.168.2.XXX appears to be up ... good.
...
Post by NoOp
Host <hostname> (192.168.2.XXX) appears to be up ... good.
"Obfuscation apparent" because it isn't showing hostnames?
I believe he means /he's obfuscated/ the host names and IPS.

Matt Flaschen
NoOp
2009-01-17 04:20:24 UTC
Permalink
Post by Matthew Flaschen
Post by Derek Broughton
Post by NoOp
Yep... 4.76-1 works well after using alien. Interesting that the repo
$ nmap -T Aggressive -A -v 192.168.2.*
??
Post by NoOp
Host 192.168.2.XXX appears to be up ... good.
...
Post by NoOp
Host <hostname> (192.168.2.XXX) appears to be up ... good.
"Obfuscation apparent" because it isn't showing hostnames?
I believe he means /he's obfuscated/ the host names and IPS.
Matt Flaschen
No I meant /obfuscation/

http://en.wikipedia.org/wiki/Obfuscation
http://www.merriam-webster.com/dictionary/obfuscation

Yes, you are correct, I obfuscated the host names and IP's :-)
NoOp
2009-01-17 04:14:40 UTC
Permalink
Post by NoOp
Yep... 4.76-1 works well after using alien. Interesting that the repo
$ nmap -T Aggressive -A -v 192.168.2.*
??
<hostname>
192.168.2.XXX
MAC: X:X:X:X:X:X

I just obfuscated those rather than display all of the wonderful details
of my test network.
Derek Broughton
2009-01-18 02:07:12 UTC
Permalink
Post by NoOp
Post by NoOp
Yep... 4.76-1 works well after using alien. Interesting that the repo
$ nmap -T Aggressive -A -v 192.168.2.*
??
<hostname>
192.168.2.XXX
MAC: X:X:X:X:X:X
I just obfuscated those rather than display all of the wonderful details
of my test network.
Doh! Apparently, it wasn't "apparent" to me :-) I guess I shouldn't have
been online that late!
Brian McKee
2009-01-17 14:54:47 UTC
Permalink
Post by NoOp
Post by Derek Broughton
Post by NoOp
Cool! You uninstalled the repo's version first I presume?
Shouldn't be necessary - alien creates a deb package which supercedes the
current Ubuntu package, and a later Ubuntu package will superced the alien'd
package.
Yep... 4.76-1 works well after using alien. Interesting that the repo
$ nmap -T Aggressive -A -v 192.168.2.*
Host 192.168.2.XXX appears to be up ... good.
Not shown: 1712 closed ports
PORT STATE SERVICE VERSION
139/tcp open netbios-ssn Samba smbd 3.X (workgroup: MSHOME)
445/tcp open netbios-ssn Samba smbd 3.X (workgroup: MSHOME)
5900/tcp open vnc VNC (protocol 3.7)
Host <hostname> (192.168.2.XXX) appears to be up ... good.
Not shown: 996 closed ports
PORT STATE SERVICE VERSION
139/tcp open netbios-ssn Samba smbd 3.X (workgroup: MSHOME)
445/tcp open netbios-ssn Samba smbd 3.X (workgroup: MSHOME)
5900/tcp open vnc VNC (protocol 3.7)
16001/tcp open tcpwrapped
|_ NBSTAT: NetBIOS name: <hostname>, NetBIOS MAC: X:X:X:X:X:X
| Discover OS Version over NetBIOS and SMB: Unix
|_ Discover system time over SMB: 2009-01-16 17:02:58 UTC-8
So the newer version adds some nice details.
The guy that wrote nmap did a presentation at BlackHat ? where he
talks about the new features. Apparently he basically portscanned
really large swathes of the internet to help statistically prove what
ports and services the default scans should look for. If you think
about that for a minute you can imagine what problems he had with his
ISP etc :-) An interesting video - which I *think* is on the site
somewhere. If you can't find it and are interesting drop me a line
off list and I'll find it for you.

As far as the dns-sd command - that's Bonjour/Apple specific. As I
pointed out earlier, use the avahi-* commands on Ubuntu.

And since those commands look at the local cache rather than poke
around on the network - they are certainly more efficient - although
the discussion as to which tool is 'better' is kinda silly. They both
accomplish the result in different ways under different circumstances.

Brian
NoOp
2009-01-16 21:20:03 UTC
Permalink
Post by Charles Darwin
Post by Chris Mohler
sudo nmap -sP 10.0.1.*
That was nice but still `dns-sd -B _ssh._tcp .` is faster. How do you
tell nmap to only look for those that broadcast ssh?
sudo nmap 192.168.2.* -p T:22

Nmap done: 256 IP addresses (6 hosts up) scanned in 2.741 seconds
Charles Darwin
2009-01-17 02:27:35 UTC
Permalink
Post by NoOp
Nmap done: 256 IP addresses (6 hosts up) scanned in 2.741 seconds
-bash-3.2$ uname -v && time dns-sd -B _ssh._tcp .
Darwin Kernel Version 9.6.0: Mon Nov 24 17:37:00 PST 2008;
root:xnu-1228.9.59~1/RELEASE_I386
Browsing for _ssh._tcp
Timestamp A/R Flags if Domain Service
Type Instance Name
21:22:16.685 Add 2 1 local.
_ssh._tcp. Ubermensch
^C

real 0m0.799s
user 0m0.001s
sys 0m0.002s

It seems to me using nmap "for what we are trying to do here" is like
using an artillery shell to knock out a mosquito, don't you thinnk?
NoOp
2009-01-17 03:07:02 UTC
Permalink
Post by Charles Darwin
Post by NoOp
Nmap done: 256 IP addresses (6 hosts up) scanned in 2.741 seconds
-bash-3.2$ uname -v && time dns-sd -B _ssh._tcp .
Darwin Kernel Version 9.6.0: Mon Nov 24 17:37:00 PST 2008;
root:xnu-1228.9.59~1/RELEASE_I386
Browsing for _ssh._tcp
Timestamp A/R Flags if Domain Service
Type Instance Name
21:22:16.685 Add 2 1 local.
_ssh._tcp. Ubermensch
^C
real 0m0.799s
user 0m0.001s
sys 0m0.002s
It seems to me using nmap "for what we are trying to do here" is like
using an artillery shell to knock out a mosquito, don't you thinnk?
No. As it doesn't work on my machine.

1. $ uname -v && time dns-sd -B _ssh._tcp .
#1 SMP Thu Nov 27 18:44:42 UTC 2008
bash: dns-sd: command not found

real 0m0.274s
user 0m0.200s
sys 0m0.052s

2. The OP asked:

<quote>
I have just installed ubuntu onto a machine and have connected it to
my LAN. The router provides DHCP and the new machine is up and
running on the network.

How do I connect *to* the machine? I need to know its IP address and,
as there are a few devices which get their address by DHCP it's not at
all obvious what the machine's address is.

Eventually I will probably give it a fixed address (for this reason
among others).
</quote>

and then stated:

<quote>
Quite right, so I have a machine that runs sshd and I want to connect
to it and I know it's on the LAN but not its IP address.
</quote>

sudo nmap 192.168.2.* -p T:22

took like 2+ seconds on my tiny test network with the machines I
currently have up, scanned 6 machines (including 2 routers), and
provided me with: 1) IP address, port state (open, closed, filtered), 2)
the host name of the machine (if any), and 3) the MAC address of each
machine. It appears to me that your mosquito (albeit a fast one) is just
that, a moquito :-)

Ping - Chris G: You started this thread, how about posting back
regarding the options provided?
Charles Darwin
2009-01-17 12:42:19 UTC
Permalink
Post by NoOp
Post by Charles Darwin
Post by NoOp
Nmap done: 256 IP addresses (6 hosts up) scanned in 2.741 seconds
-bash-3.2$ uname -v && time dns-sd -B _ssh._tcp .
Darwin Kernel Version 9.6.0: Mon Nov 24 17:37:00 PST 2008;
root:xnu-1228.9.59~1/RELEASE_I386
Browsing for _ssh._tcp
Timestamp A/R Flags if Domain Service
Type Instance Name
21:22:16.685 Add 2 1 local.
_ssh._tcp. Ubermensch
^C
real 0m0.799s
user 0m0.001s
sys 0m0.002s
It seems to me using nmap "for what we are trying to do here" is like
using an artillery shell to knock out a mosquito, don't you thinnk?
No. As it doesn't work on my machine.
1. $ uname -v && time dns-sd -B _ssh._tcp .
#1 SMP Thu Nov 27 18:44:42 UTC 2008
bash: dns-sd: command not found
real 0m0.274s
user 0m0.200s
sys 0m0.052s
<quote>
I have just installed ubuntu onto a machine and have connected it to
my LAN. The router provides DHCP and the new machine is up and
running on the network.
So here you do have physical access to the machine. To get your IP
simply run:

ipconfig getifaddr en0 #for Ethernet
ipconfig getifaddr en1 #for Wireless

You can wrap either of them (or both) in a script and have the script
send you an email with the IP(s). nmap to artillery shell for a
mosquito analogy would still work here.
Post by NoOp
How do I connect *to* the machine? I need to know its IP address and,
as there are a few devices which get their address by DHCP it's not at
all obvious what the machine's address is.
Eventually I will probably give it a fixed address (for this reason
among others).
</quote>
<quote>
Quite right, so I have a machine that runs sshd and I want to connect
to it and I know it's on the LAN but not its IP address.
</quote>
Now this seems like a different scenario. This seems to me (although
not quite clear) like you do NOT have physical access to the machine
that you want to ssh into (this is what I mean by "what we are trying
to do here" BTW) and dns-sd is way faster for that unless you can
figure out how to run nmap super light so it can bit dns-sd which is
not an easy task; Zeroconf is optimized for sending/receiving minimum
number of packages for service discovery and now you want to beat that
by simply tweaking the nmap which is designed to do much more and is
not necessarily brief in what does; I say good luck with that. On the
other hand, I think, if you can find a default utility on linux (which
I'm pretty sure there is one but I just don't know it), or better yet
*nix, that would do a quick service discovery, then you're on you're
way to somewhere.
NoOp
2009-01-18 02:36:41 UTC
Permalink
Post by Charles Darwin
Post by NoOp
Post by Charles Darwin
Post by NoOp
Nmap done: 256 IP addresses (6 hosts up) scanned in 2.741 seconds
-bash-3.2$ uname -v && time dns-sd -B _ssh._tcp .
Darwin Kernel Version 9.6.0: Mon Nov 24 17:37:00 PST 2008;
root:xnu-1228.9.59~1/RELEASE_I386
Browsing for _ssh._tcp
Timestamp A/R Flags if Domain Service
Type Instance Name
21:22:16.685 Add 2 1 local.
_ssh._tcp. Ubermensch
^C
real 0m0.799s
user 0m0.001s
sys 0m0.002s
It seems to me using nmap "for what we are trying to do here" is like
using an artillery shell to knock out a mosquito, don't you thinnk?
No. As it doesn't work on my machine.
1. $ uname -v && time dns-sd -B _ssh._tcp .
#1 SMP Thu Nov 27 18:44:42 UTC 2008
bash: dns-sd: command not found
real 0m0.274s
user 0m0.200s
sys 0m0.052s
<quote>
I have just installed ubuntu onto a machine and have connected it to
my LAN. The router provides DHCP and the new machine is up and
running on the network.
So here you do have physical access to the machine. To get your IP
ipconfig getifaddr en0 #for Ethernet
ipconfig getifaddr en1 #for Wireless
You can wrap either of them (or both) in a script and have the script
send you an email with the IP(s). nmap to artillery shell for a
mosquito analogy would still work here.
And I would want to do that why? Sorry, but perhaps I'm missing the big
picture here.

~$ ipconfig getifaddr en0
bash: ipconfig: command not found

$ ipconfig
bash: ipconfig: command not found

Are you perhaps running running something other than Ubuntu (I'm running
8.04.1)?

Apparently you are, as ipconfig only works in Windows (maybe others) as
far as I know.

If you are offering advise to the OP on how to check the Ubuntu machine
from Windows that might work (I've not tried it)... as would nmap
installed on Windows.
Post by Charles Darwin
Post by NoOp
How do I connect *to* the machine? I need to know its IP address and,
as there are a few devices which get their address by DHCP it's not at
all obvious what the machine's address is.
Eventually I will probably give it a fixed address (for this reason
among others).
</quote>
<quote>
Quite right, so I have a machine that runs sshd and I want to connect
to it and I know it's on the LAN but not its IP address.
</quote>
Now this seems like a different scenario. This seems to me (although
not quite clear) like you do NOT have physical access to the machine
that you want to ssh into (this is what I mean by "what we are trying
to do here" BTW) and dns-sd is way faster for that unless you can
Why do you keep referring to dns-sd? Can you point to a reference in
Ubuntu (any version) regarding it's use other than with Avahi as Brian
pointed out or perhaps mdns-scan?

I'm not trying to be confrontational, I'm just trying to figure out what
this 'dns-sd' is that you are referring to and how to use it.

http://www.dns-sd.org/

Indicates that it's a Mac/Apple thing... so how does it apply here?
Post by Charles Darwin
figure out how to run nmap super light so it can bit dns-sd which is
not an easy task; Zeroconf is optimized for sending/receiving minimum
number of packages for service discovery and now you want to beat that
by simply tweaking the nmap which is designed to do much more and is
not necessarily brief in what does; I say good luck with that. On the
other hand, I think, if you can find a default utility on linux (which
I'm pretty sure there is one but I just don't know it), or better yet
*nix, that would do a quick service discovery, then you're on you're
way to somewhere.
Lost me there & pretty much everywhere regarding your suggestions.
Derek Broughton
2009-01-18 03:23:27 UTC
Permalink
...
Post by NoOp
And I would want to do that why? Sorry, but perhaps I'm missing the big
picture here.
~$ ipconfig getifaddr en0
bash: ipconfig: command not found
$ ipconfig
bash: ipconfig: command not found
Are you perhaps running running something other than Ubuntu (I'm running
8.04.1)?
Well, yeah. "Darwin" is a clue, eh?
NoOp
2009-01-18 03:52:55 UTC
Permalink
Post by Derek Broughton
...
Post by NoOp
And I would want to do that why? Sorry, but perhaps I'm missing the big
picture here.
~$ ipconfig getifaddr en0
bash: ipconfig: command not found
$ ipconfig
bash: ipconfig: command not found
Are you perhaps running running something other than Ubuntu (I'm running
8.04.1)?
Well, yeah. "Darwin" is a clue, eh?
I suppose. As is this:
X-Mailer: Apple Mail (2.930.3)
Derek Broughton
2009-01-17 03:40:54 UTC
Permalink
Post by Charles Darwin
Post by NoOp
Nmap done: 256 IP addresses (6 hosts up) scanned in 2.741 seconds
-bash-3.2$ uname -v && time dns-sd -B _ssh._tcp .
Darwin Kernel Version 9.6.0: Mon Nov 24 17:37:00 PST 2008;
root:xnu-1228.9.59~1/RELEASE_I386
Browsing for _ssh._tcp
Timestamp A/R Flags if Domain Service
Type Instance Name
21:22:16.685 Add 2 1 local.
_ssh._tcp. Ubermensch
^C
real 0m0.799s
user 0m0.001s
sys 0m0.002s
It seems to me using nmap "for what we are trying to do here" is like
using an artillery shell to knock out a mosquito, don't you think?
Funny, I would have said using dns-sd was the artillery shell. All nmap was
doing was sending a few packets to see if it got responses. dsn-sd is
looking for broadcasting services - which means your clients need to be
broadcasting. So nmap takes longer - are we in a rush?
Brian McKee
2009-01-16 21:38:30 UTC
Permalink
I used to use nmap but then I found this on my mac (much faster for what
dns-sd -B _ssh._tcp .
This works with Zeroconf and (from man dns-sd's) supposedly comes with BSD.
1. Is there something like this unique to *nix?
Apple's version is Bonjour/Rendevous. Bonjour is avail for Windows and
Linux, but most linux these days ship Avahi (license issues)

Try avahi-browse -ta

And nmap scans for open ports, avahi/bonjour listens for broadcasting
services - quite different !

Brian
Matthew Flaschen
2009-01-16 23:59:31 UTC
Permalink
Post by Thomas Kaiser
You can use nmap in a terminal to scan the network for open ports.
thomas at AMD64:~$ nmap 192.168.0.*
Port-scanning doesn't tell him which computer has which IP, only that
there are several computers, each with /an/ IP. He said, "there are a
few devices which get their address by DHCP".

Matt Flaschen
Derek Broughton
2009-01-17 00:58:41 UTC
Permalink
Post by Matthew Flaschen
Post by Thomas Kaiser
You can use nmap in a terminal to scan the network for open ports.
thomas at AMD64:~$ nmap 192.168.0.*
Port-scanning doesn't tell him which computer has which IP, only that
there are several computers, each with /an/ IP. He said, "there are a
few devices which get their address by DHCP".
I'm not seeing the difference here - nmap certainly shows all the computers
on my local network, with names (if we know them) and IPs - and all of them
got their address by DHCP, so why do you think it won't tell which computer
has which IP? (in fact, you never know which "computer" has an IP, only
which MAC address - which is generally, but not always, close enough).
Matthew Flaschen
2009-01-17 01:06:02 UTC
Permalink
Post by Derek Broughton
Post by Matthew Flaschen
Post by Thomas Kaiser
You can use nmap in a terminal to scan the network for open ports.
thomas at AMD64:~$ nmap 192.168.0.*
Port-scanning doesn't tell him which computer has which IP, only that
there are several computers, each with /an/ IP. He said, "there are a
few devices which get their address by DHCP".
I'm not seeing the difference here - nmap certainly shows all the computers
on my local network, with names (if we know them) and IPs - and all of them
got their address by DHCP, so why do you think it won't tell which computer
has which IP?
If it says:

Interesting ports on 192.168.0.11:
Not shown: 1712 filtered ports
PORT STATE SERVICE
80/tcp open http
443/tcp open https

Interesting ports on 192.168.0.17:
Not shown: 1712 filtered ports
PORT STATE SERVICE
80/tcp open http
443/tcp open https

how does that allow him to figure out which computer is which?

Matt Flaschen
Derek Broughton
2009-01-17 04:01:37 UTC
Permalink
Post by Matthew Flaschen
Post by Derek Broughton
Post by Matthew Flaschen
Post by Thomas Kaiser
You can use nmap in a terminal to scan the network for open ports.
thomas at AMD64:~$ nmap 192.168.0.*
Port-scanning doesn't tell him which computer has which IP, only that
there are several computers, each with /an/ IP. He said, "there are a
few devices which get their address by DHCP".
I'm not seeing the difference here - nmap certainly shows all the
computers on my local network, with names (if we know them) and IPs - and
all of them got their address by DHCP, so why do you think it won't tell
which computer has which IP?
Not shown: 1712 filtered ports
PORT STATE SERVICE
80/tcp open http
443/tcp open https
Not shown: 1712 filtered ports
PORT STATE SERVICE
80/tcp open http
443/tcp open https
how does that allow him to figure out which computer is which?
$ sudo nmap -sP 192.168.0.1/23
Starting Nmap 4.62 ( http://nmap.org ) at 2009-01-16 23:53 AST
Host 192.168.0.1 appears to be up.
Host 192.168.0.3 appears to be up.
Host 192.168.1.1 appears to be up.
MAC Address: 00:13:10:9F:68:2B (Cisco-Linksys)
Host 192.168.1.2 appears to be up.
MAC Address: 00:13:10:9F:68:25 (Cisco-Linksys)
Host bella.pointerstop.ca (192.168.1.101) appears to be up.
Host Wii.pointerstop.ca (192.168.1.102) appears to be up.
MAC Address: 00:1E:A9:8E:DC:CB (Nintendo Co.)
Nmap done: 512 IP addresses (5 hosts up) scanned in 8.073 seconds
Shows all three routers (192.168.0.3 took a little thought - it's the
_external_ address of the wifi router at 192.168.1.1), my current machine
and the neighbour's Wii (he should be in bed by now!)
Chris Mohler
2009-01-17 04:17:15 UTC
Permalink
On Sat, Jan 17, 2009 at 10:01 PM, Derek Broughton <derek at pointerstop.ca> wrote:
[...]
Post by Derek Broughton
Shows all three routers (192.168.0.3 took a little thought - it's the
_external_ address of the wifi router at 192.168.1.1), my current machine
and the neighbour's Wii (he should be in bed by now!)
Ah, but a Wii lurks around after bedtime looking for updates, etc.
unless you power it down fully...

Chris
Derek Broughton
2009-01-18 02:05:37 UTC
Permalink
Post by Chris Mohler
[...]
Post by Derek Broughton
Shows all three routers (192.168.0.3 took a little thought - it's the
_external_ address of the wifi router at 192.168.1.1), my current
machine and the neighbour's Wii (he should be in bed by now!)
Ah, but a Wii lurks around after bedtime looking for updates, etc.
unless you power it down fully...
I don't know the actual usage. I was surprised to see that it actually
shows up on about every second nmap scan, so it seems it isn't even fully
online. Interesting.
Smoot Carl-Mitchell
2009-01-16 19:36:06 UTC
Permalink
Post by Chris G
O
Quite right, so I have a machine that runs sshd and I want to connect
to it and I know it's on the LAN but not its IP address.
You can always scan your subnetwork with a portscanning tool like nmap.
--
Smoot Carl-Mitchell
Computer Systems and
Network Consultant
smoot at tic.com
+1 480 922 7313
cell: +1 602 421 9005
Matthew Flaschen
2009-01-16 23:56:25 UTC
Permalink
Post by Chris G
OK, thanks, not much use from the other end though is it!
How is your computer supposed to know which other computer you want the
IP /of/, and how is it supposed to reach it to "ask"? It's the same as
saying, "Honey, what was that nice man's name?" Now, if you knew a
hostname, or NetBIOS name, or something, you'd have a starting place.
But it sounds like you don't.

Matt Flaschen
Wade Smart
2009-01-16 17:34:22 UTC
Permalink
Post by Chris G
I have just installed ubuntu onto a machine and have connected it to
my LAN. The router provides DHCP and the new machine is up and
running on the network.
How do I connect *to* the machine? I need to know its IP address and,
as there are a few devices which get their address by DHCP it's not at
all obvious what the machine's address is.
Eventually I will probably give it a fixed address (for this reason
among others).
20090116 1133 GMT-5

System > Network Toos > Devices Tab, select eth0 and it will tell you
the ip of that machine.

Wade
--
Registered Linux User: #480675
Linux since June 2005
Neil Cherry
2009-01-16 18:09:59 UTC
Permalink
Post by Chris G
I have just installed ubuntu onto a machine and have connected it to
my LAN. The router provides DHCP and the new machine is up and
running on the network.
How do I connect *to* the machine? I need to know its IP address and,
as there are a few devices which get their address by DHCP it's not at
all obvious what the machine's address is.
Eventually I will probably give it a fixed address (for this reason
among others).
ifconfig

Output will look like this:

eth0 Link encap:Ethernet HWaddr 00:0D:B9:13:14:38
inet addr:192.168.24.99 Bcast:192.168.24.0 Mask:255.255.255.0
UP BROADCAST MULTICAST MTU:1500 Metric:1
RX packets:0 errors:0 dropped:0 overruns:0 frame:0
TX packets:0 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1000
RX bytes:0 (0.0 b) TX bytes:0 (0.0 b)
Interrupt:10 Base address:0x1000

lo Link encap:Local Loopback
inet addr:127.0.0.1 Mask:255.0.0.0
UP LOOPBACK RUNNING MTU:16436 Metric:1
RX packets:294 errors:0 dropped:0 overruns:0 frame:0
TX packets:294 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:0
RX bytes:30124 (29.4 Kb) TX bytes:30124 (29.4 Kb)


Note that this machine does not have it's WiFi enabled. This machine's
IP address is 192.168.24.99 (eth0). You could get fancy by using
regular expressions (egrep) but that might seem a bit scary for the
uninitiated.


Hmm, odd that machine appears to have broken counters, oh well I'll
fix that later.
--
Linux Home Automation Neil Cherry ncherry at linuxha.com
http://www.linuxha.com/ Main site
http://linuxha.blogspot.com/ My HA Blog
Author of: Linux Smart Homes For Dummies
Alex Katebi
2009-01-16 18:09:53 UTC
Permalink
Go to your router. http://192.168.1.1 and you can see all the active devices
with thier ip addresses.
Post by Chris G
I have just installed ubuntu onto a machine and have connected it to
my LAN. The router provides DHCP and the new machine is up and
running on the network.
How do I connect *to* the machine? I need to know its IP address and,
as there are a few devices which get their address by DHCP it's not at
all obvious what the machine's address is.
Eventually I will probably give it a fixed address (for this reason
among others).
--
Chris Green
--
ubuntu-users mailing list
ubuntu-users at lists.ubuntu.com
https://lists.ubuntu.com/mailman/listinfo/ubuntu-users
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Chris G
2009-01-16 18:51:33 UTC
Permalink
Go to your router. [1]http://192.168.1.1 and you can see all the active
devices with thier ip addresses.
... and how do I know which is which?
--
Chris Green
Florian Primessnig
2009-01-16 18:23:59 UTC
Permalink
hi,
u dont need to setup a static ip-adress. configure your dhcp server to
provide host&domainnames for clients by MAC adresses.
or u could configure a proper machine name on that client that can be
resolved on your lan, e.g. like myclient.local
Post by Chris G
I have just installed ubuntu onto a machine and have connected it to
my LAN. The router provides DHCP and the new machine is up and
running on the network.
How do I connect *to* the machine? I need to know its IP address and,
as there are a few devices which get their address by DHCP it's not at
all obvious what the machine's address is.
Eventually I will probably give it a fixed address (for this reason
among others).
Derek Broughton
2009-01-16 18:24:08 UTC
Permalink
Post by Chris G
I have just installed ubuntu onto a machine and have connected it to
my LAN. The router provides DHCP and the new machine is up and
running on the network.
How do I connect *to* the machine? I need to know its IP address and,
as there are a few devices which get their address by DHCP it's not at
all obvious what the machine's address is.
Eventually I will probably give it a fixed address (for this reason
among others).
Pointless. Have you tried just addressing it by name? Decent routers set
up the DNS too.

I see so many people telling us that they "need" static IPs, but the
technology is way beyond that.
NoOp
2009-01-16 19:29:38 UTC
Permalink
Post by Chris G
I have just installed ubuntu onto a machine and have connected it to
my LAN. The router provides DHCP and the new machine is up and
running on the network.
How do I connect *to* the machine? I need to know its IP address and,
as there are a few devices which get their address by DHCP it's not at
all obvious what the machine's address is.
Eventually I will probably give it a fixed address (for this reason
among others).
sudo apt-get install nmap

and scan for machines on your network. Example:

$ sudo nmap -sP 192.168.2.0/24 |grep up
Host 192.168.2.1 appears to be up.
Host 192.168.2.100 appears to be up.
Host main (192.168.2.101) appears to be up.
Host main3 (192.168.2.104) appears to be up.
Host 192.168.2.108 appears to be up.
Nmap done: 256 IP addresses (5 hosts up) scanned in 2.488 seconds

In the above example:

192.168.2.1 is a router
192.168.2.108 is a router [1]
192.168.2.101 is a WinXP machine
192.168.2.100 is this machine

[1] machines on the other side of 108 aren't shown as they are on a
different subnet & I only scan the 192.168.2.0/24 in this example. You
can google for nmap to find out how to scan outside of your subnet. Just
be careful that you don't go scanning too far as some/many/all networks
find scans to be intrusive.

If you want details (MAC address etc), then use the '-vv' mode:

$ sudo nmap -vv -sP 192.168.2.0/24

and you'll get the MAC addresses for the hosts that are up.

If you prefer a GUI frontend to nmap, you can try zenmap:

sudo apt-get install zenmap

Disclaimer: I've not used zenmap (yet), but added info is here:
http://www.net-security.org/secworld.php?id=5675
NoOp
2009-01-16 19:34:13 UTC
Permalink
Post by NoOp
sudo apt-get install zenmap
http://www.net-security.org/secworld.php?id=5675
Sorry, I gave you the wrong URL. The correct URL is:

http://nmap.org/book/zenmap.html
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