Forcing static address in 12.04

Joel Rees joel.rees at gmail.com
Sat Jun 13 01:17:31 UTC 2015


2015/06/13 7:45 "rikona" <rikona at sonic.net>:
>
> Hello Joel,
>
> Thursday, June 11, 2015, 6:09:00 AM, Joel wrote:
>
>
> >>> > network 192.168.0.0
> >>
> >> Nope, not at all. That combination will work just fine, though the
> >> network statement is misleading and unnecessary.
>
> > But don't you think it odd that he is back on-line after getting rid
> > of that "misleading" definition of the base address of his network
> > segment?
>
> That line was there in only one of several tries, none of which
> worked. Probably not the thing that fixed it.

IP is pretty simple, but the best kind of simplicity hides some complexities.

I'm guessing, but I won't go beyond guessing, that getting that line
out of that file was part of the process of getting the network
definitions sane.

Anyway, it helps you understand the structure of IP addresses.

> It was, though, in the
> blow-up try. :-) Could that have caused the blow-up? If so, how?

Not highly likely, but not impossible.

Sometimes, when I'm working on a function, I go down a wrong path with
more than one error in my thinking, and in the code. And, when I get
my thinking straightened out, I discover that it doesn't make sense to
try to point at every possible wrong turn I made. You had lots of
things that were in conflict.

I have had a mis-configured nic drag a box into the tarpits, such that
it was necessary to manually force a re-boot. Consider that the nic,
being a high-bandwidth device, has the ability to interrupt the CPU at
a very high rate. That doesn't leave a lot of CPU time for other jobs,
including refreshing the display at a timely rate. Interrupt rates too
high can even drag all the cores of a multi-core CPU into the mud. And
slow screen updates can appear to be a screen gone crazy.

If interrupts occur so fast that one interrupt handler is not finished
before the CPU tries to handle the next, memory can be walked on, etc.

Theoretically, yeah, it could have been part of the cause. Maybe. Or
it could have been something else, which is something you want to
consider carefully. (Check for unwanted software?)

> > Well, I must admit, I am wondering whether the factory settings of
> > the ASUS RT-N65R would have the router in the same network as the
> > box in question if he used a /24.
>
> It is not the default - I input the address to use.

It did not look like a factory setting. Which is kind of unfortunate.

If I made routers, I hope that I would have the ambition to figure out
a way to randomly set the default network to something other than the
common 192.168.0.0 or 192.168.1.0 networks, among other things
designed to reduce the profitability of attacking the routers I made.

> > Not that I'm interested enough to download the manual PDF to find
> > out.
>
> Saved you a bit of work. :-)

:)

I do hope you have the manual handy. Most manuals these days seem to
be overweighted with advertizing, but they still have some important
information in them.

Joel Rees



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