Simple Ad-hoc Ethernet connect between 2 PCS

Xeratul · 05-02-2017, 01:49 AM

Hello,

There is here the following hardware:
PC1-RJ45-ETH0 <-----ethernet cable----> PC2-RJ45-ETH3

How would you connect them so that they can see each other on a local 192.168.1.x??

The idea would be to do it with command line:
ifup
ifdown
ifconfig
dhclient

I bought a crossover cable.

my idea :
ifconfig eth0 192.168.1.2
ifconfig eth0 192.168.1.3
and then dhclient on both

Would you have any inputs? I did it in the past, but I cannot remember how I managed.

Thank you

Ser Olmy · 05-02-2017, 03:36 AM

Running dhclient means you're trying to get an IP address from a DHCP server. In this particular scenario, no DHCP service can be found on the LAN segment, so the DHCP operation will fail.

After a while, dhclient should assign an APIPA link-local IP address to the interface. In other words, the computers should be able to communicate using the automatically assigned 169.254.x.x addresses.

IF you want to use addresses in the 192.168.1.0/24 network, you'll have to assign addresses manually. In fact, that's exactly what you're doing if you run ifconfig as you suggested, so if you just leave dhclient out of it, everything should work.

Xeratul · 05-02-2017, 07:16 AM

Quote:

Originally Posted by Ser Olmy

Running dhclient means you're trying to get an IP address from a DHCP server. In this particular scenario, no DHCP service can be found on the LAN segment, so the DHCP operation will fail.

After a while, dhclient should assign an APIPA link-local IP address to the interface. In other words, the computers should be able to communicate using the automatically assigned 169.254.x.x addresses.

IF you want to use addresses in the 192.168.1.0/24 network, you'll have to assign addresses manually. In fact, that's exactly what you're doing if you run ifconfig as you suggested, so if you just leave dhclient out of it, everything should work.

First, ifdown eth0 and ifdown eth3.

First pc:
Would you think that I should give it, with static:

Code:

# The loopback network interface
# auto lo                          
# iface lo inet loopback
iface eth0 inet static
address 192.168.1.23

Second pc:

Code:

# The loopback network interface
# auto lo                          
# iface lo inet loopback
iface eth3 inet static
address 192.168.1.24

and give 192.168.1.23 to the other one, with static.

Then, on both, to do the ifup eth3 and ifup eth0.

I tried this "interface" file, but it did NOT work

Xeratul · 05-02-2017, 01:55 PM

Hi Guys,

I have now INTERNET and can surf

I bought a Router to save time, since I needed it. The router does take care of the DHCP server.
I believe that the method I used in the past is outdated. Many forums talk about wlan0 but a crossover ? Today, does it make any single sense to make a backup using a crossover ethernet cable? Future is wifi and high speed transferts. There will be more and more wireless in the future, with more data (waves) going in the air.

I added only :

Code:

iface eth3 inet dhcp 
iface eth0 inet dhcp

[Shall I make it as Thread Solved??]

jefro · 05-02-2017, 03:27 PM

Almost no one needs a crossover cable anymore. Almost every nic and router made in the last 15 years has a way to adjust for the patch or crossover cable by the way. They sometimes won't correct unless you power down fully however.

Wireless may be getting faster but so is wired.

Xeratul · 05-05-2017, 11:51 PM

Quote:

Originally Posted by jefro

Almost no one needs a crossover cable anymore. Almost every nic and router made in the last 15 years has a way to adjust for the patch or crossover cable by the way. They sometimes won't correct unless you power down fully however.

Wireless may be getting faster but so is wired.

And, you have nothing against having very high-speed wireless, right? Let's talk in 20 years, again...

Of course, for data backup, the crossover makes sense for home purpose, still today.