[xubuntu-users] networking

[Bill]

On 03/31/2013 05:26 PM, Nils Kassube wrote:
> Bill wrote:
>> I have a home network consisting of a desktop, laptop and dsl
>> modem/router. I'm running xubuntu 12.04 on both computers (Linux
>> xxxx-xxx-xxxxx 3.2.0-39-generic-pae #62-Ubuntu SMP Wed Feb 27 22:25:11
>> UTC 2013 i686 i686 i386 GNU/Linux). Everything worked without a flaw
>> until I had to reset the router following an isp (CenturyLink)
>> problem.
>>
>> Now I can connect to the internet, and ping the gateway from both
>> computers, but can not ssh or rsync or ping from one computer to the
>> other. (However, I can telnet to port 22.) Attempts to connect yield
>> "Destination Host Unreachable". So far as I can tell, all software and
>> hardware necessary to doing so are installed and working properly.
>
> Are you using IP addresses or machine names when you try to ping, ssh,
> etc.? How do the machines get their IP addresses? Do you use manual
> address setup or DHCP? If it is DHCP, the router may have decided to
> hand out different addresses than in the past after the reset.

IP addresses (i.e., 192.168.2.2, etc.), which are not manually assigned, 
so I assume DHCP.

>> I have disabled and re-enabled all firewalls and iptables to no avail.
>
> So you tested the connection between the boxes with firewalls disabled?

Yes.

>> It must be something so simple that I am overlooking it; I had it set
>> up and it worked... I also played with the router configuration (port
>> forwarding to port 22 on both machines, changing the default server,
>> etc.).
>
> The port forwarding etc. are only relevant for connections from the
> internet to your LAN, not within your LAN. At the LAN side the router
> should work as a switch (unless you have an unusual setup for a home
> network).
>
>> My thought is that perhaps through the many updates that have been
>> made since the release of 12.04 something of which I was unaware in
>> the networking configuration has changed (both machines dual boot to
>> Ubuntu 12.04, and I have the same problem in it)?
>
> Has the problem started after an update or after resetting the router?
> According to what you wrote above, I would assume that it was the
> latter, And as it is the same problem with Xubuntu and Ubuntu, it is
> certainly caused by resetting the router.

It presented after resetting the router. My speculation was that it may 
have worked like the operating system does when an upgrade requires a 
reboot; i.e., the changes do not take effect until the machine is 
rebooted; that things continued to work properly in spite of system 
changes until I rebooted the router. Does not make much sense, but I'm 
left to speculate since I do not understand what but resetting the 
router causes the "Destination Host Unreachable" effect.

> Nils

--
Regards,
Bill