[Discuss] network issue

[jdm at moylan.us (dan moylan)]

bill writes:
> On 3/13/2014 7:25 PM, dan moylan wrote:
>> tom writes:
>>> dan moylan wrote:
>>>> the ethernet port is hard wired into the router...
>>>> ...but nothing happens.
>>> It sounds like DHCP is not working. The next question is why.

> Let's back up a bit. Please do these tests and report results:
> 1. If you manually assign an IP address to the NIC, can
> you ping it?

yes.

> 2. Assuming you can ping the NIC, can you ping the router?

yes.

> If not, have you checked the Ethernet cable?

> 3. If you're using a "known good" Ethernet cable, what do
> the logs show?

eth0: link up

john writes:
>On Mar 13, 2014, at 7:25 PM, dan moylan <jdm at moylan.us> wrote:

>> however, when i enter sudo ifconfig eth0 up, i get connected
>> to the LAN, and can ssh into the other linux computer on the
>> LAN, but can't see out -- frustrating.

> Sounds to me like the default route is messed up.

> If you're setting it correctly on the command line, then
> maybe NetworkManager is noticing your changes and
> automatically changing them back to the wrong settings. I
> had a similar issue a few years ago while installing a new
> server where an overly aggressive NetworkManager daemon was
> ultimately the culprit, and I had to disable NetworkManager
> to get networking to function correctly.

> Just to cover all bases:

> You ran "ifconfig eth0 up" to bring up the Ethernet
> interface, and that got its ip address via dhcp, correct?

yes.

> This gets you the ip address, which enables you to reach
>  other machines on the same subnet, but it does *NOT* set
> the default route for you.

yes.

> Did you set the default route by running "route add --net
> default gw ROUTER-ADDRESS"?

yes, although i did get the message "NET/ROM needs to be
written".  route looks ok though.

thanks,
ole dan

j. daniel moylan
84 harvard ave
brookline, ma 02446-6202
617-232-2360 (tel)
jdm at moylan.us
www.moylan.us
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