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Linux - Networking This forum is for any issue related to networks or networking.
Routing, network cards, OSI, etc. Anything is fair game.

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Old 12-14-2008, 04:41 AM   #16
repo
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Seems to me, the router gives the same public ip recieved from the ISP to the 2 computers connected to LAN
The wireless also recieves a public IP from the router (probably also 67.63.55.3), but gives out private ip's to the connected computers.
It's a crappy setup anyway.

Last edited by repo; 12-14-2008 at 04:42 AM.
 
Old 12-14-2008, 04:53 AM   #17
x_terminat_or_3
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Possible, but the router would have to know what computer sent what packet, and what packet is destined for what computer. This is done through Network Address Translation, and it implies that those pc's have a private, class C IP address on the same subnet as the one used for doing nmap.

I think the best solution would be, as mentioned previously in this post, to statically set the IP address of all PCs on the network. Whether this is done by reserving addresses on the DHCP server (Router), or, on the clients (pc), doesn't really matter.
 
Old 12-14-2008, 04:56 AM   #18
x_terminat_or_3
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Also, consider that, a firewall may be dropping the ping probes nmap sends to `emachine' and `mimi'.

To test this, go to `emachine' and temporary disable its firewall, then do your nmap scan again. If `emachine' shows up now, then that's the culprit, and you'll have to dig in the documentation for the firewall you're using to allow ICMP echo request and ICMP echo reply
 
Old 12-14-2008, 09:38 AM   #19
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Maybe that common address for his two wired machines is the external IP for his router..??
 
Old 12-14-2008, 09:43 AM   #20
repo
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Quote:
Maybe that common address for his two wired machines is the external IP for his router..??
Yes, but why does it give the same address twice, and probably also to the wireless router.
He should use a router behind this router, which gives out private ip's, just like the wireless one does.
 
Old 12-14-2008, 10:54 AM   #21
puszikam
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Thanks everyone for the advice.
I am really reluctant to make any changes to the working environment, especially in view of the problems I already had with trying to change the Linpus Lite setup.
All I want is to know the address of the other computers so I can mount their drives.
I guess I will continue to obtain this by accessing my router which associates the IP's with the host names since there appears to be no Linux command to give me this information.
 
Old 12-14-2008, 06:18 PM   #22
Tinker06
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I'm going to guess that part of the underlying problem here is a bit of confusion about machine "names".
Begging forgiveness in advance if this is already clear to you -

Linux "ping" knows nothing about Windoze machine names, that is a netbios thing. When you ping a "name" on a Linux box it will use DNS or local files (/etc/hosts) to determine an IP address to ping. This "name" provided by dns is completely independent of the netbios name given to a windows machine. I gave up the Redmond Virus long ago also, but I think a ping command in a windows dos box will behave correctly using a netbios machine name, which might lead someone to believe it works that way in Linux. It would be a really good idea to find out where your machine is getting the IP address to ping when you type "ping mimi" and "ping emachine" especially since they both seem to resolve to the same (and incorrect) IP address 67.63.55.3

Finding out what is going on there might explain why you appear to have two different IP networks coming from your one DHCP server. (not normal, not usually possible, so not likely the reality)

All that being said - if you're operating on a Linux machine and you can determine the one true IP network you are running, wired and wireless, so the nmap ping command will correctly show all active machines on your net, you will have all the information you need in your arp cache after the pings. Your arp cache will show the hardware (MAC) address and IP of each machine. (type arp -n) If you know which MAC goes to which machine (normally you would keep this info in a file called /etc/ethers) it will be easy for you to see who is there and which IP address they are currently using. You could even get clever and have a bit of fun writing a script to do it for you Hope this helps.

Cheers
 
Old 12-14-2008, 09:48 PM   #23
puszikam
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Thank you tinker06.
The "arp -n" command gives me what I wanted. I can figure out which computer is which based on the HWaddress (=MAC address) and I can issue the proper mount command.
 
  


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