Re: newbie Q: making two computers communicate over a router connection

From: Joel Smith (joels_at_cbo.gov)
Date: 07/01/03


Date: 01 Jul 2003 10:16:18 -0400


when i tried arping <inet address of the other computer>. it
complained about a missing socket. so basically i couldn't even get
past the first task because i don't understand where to get the server
ip. in fact i think i'm way over my head, but that hasn't stopped me
yet.

i have two redhat 8 workstations. both have a nic connected to a
router that picks up the dynamic ip via dhcp from the DSL modem, i.e

     computer 1 <---- router ----> computer 2
                        ^
                        |
                        |
                    dsl modem
                        ^
                        |
                   phone line
                        
both computers can surf the net, but i'd like them to talk to each
other.

my questions are

1. where do i find the server ip?

2. does the redhat workstation installation come with the ability to
run a ftp, telnet and other servers? or do i need to choose the
server installation?

3. does linux set up a local network on each computer? or do all the
computers connected to the router work on the same local network?

any response greatly appreciated. thank you for your patience. at
this point i'm not hoping to make this work the way i want to, i'd
just like to learn a thing or two and maybe find a reference that
would increment my knowledge one bit at a time.

"Nick Austin" <w948293_nntp@digitalpipe.net> writes:

> If you have two computers on the same segment, in the same IP range, then
> they do not need a router to communicate.
>
> The "connection refused" message most likely means that your ftp server is
> not running, or you have a firewall blocking access.
>
> First you should try doing an 'arping <server ip>' and see if you get a
> response. If you do not get a response to this, the boxes are not really
> on the same segment, or you have other more serious connectivity
> problems.... This needs to be resolved before you can do anything cleaver
> on the TCP layer.
>
> Next, try running ftp 127.0.0.1 on the server, if you get a connection refused
> there, then there is no ftp server running. If the ftp to 127.0.0.1 works,
> then you probably have a firewall in place.
>
> Try typing 'iptables -F', and 'ipchains -F' to disable your firewall.
>
> If all else fails, then post a followup question to the news groups... :)
>
> Good luck.
>
> On Mon, 30 Jun 2003 09:53:32 -0400, Joel Smith wrote:
>
> >
> > i have two (or more) computers connected to the internet with a router. i
> > want to be able to ftp, telnet, etc. between the two computers over the
> > router connection. is there a simple way to do this? or is there a
> > document out there that addresses this (simple?) question?
> >
> > looking at netstat and ifconfig dumps out the mask, local address etc. but
> > my naive attempt to ftp between the computers, i.e.
> >
> > ftp 192....0.1
> >
> > yields something like connection refused. any suggestions?
> >
> > any help would be greatly appreciated.