[nos-bbs] JNOS on Debian Etch

George [Skip] VerDuin k8rra at ameritech.net
Thu Mar 5 22:05:04 EST 2009

Darn Jay...

Jay Nugent wrote:
> Greetings Skip,
> On Thu, 5 Mar 2009, George [Skip] VerDuin wrote:
>> Recently I fell on to a couple details where two Linux distros act 
>> differently.
>> Fedora 10 is the OS for my station and my neighbors.
>> Debian Etch is one of several distros I'm using for a project.
>> The first is seen on the establishment of tun bridge.  In the statement:
>>     ...ifconfig tun0 pointtopoint mtu 1500 up
>> it matters if the address carries a preceding zero.  This means that
>>   a)           is OK
>>   b)        fails -- resulting in an IP of
>> as seen later in both "ifconfig" and "route".  When it fails, the 
>> session acts badly.
>    It is not failing, it is doing exactly what you told it to do.  But it
> is a common mistake, so don't feel bad.  Linux lets you enter dotted-quad
> IP addresses in any of several numberical forms.  You *can* enter them in
> decimal, octal, hex, even binary!
>    .20 decimal is 20 decimal
>    .020 hex is 32 decimal (you seemed to get 39 for some reason ????)
OK - I speak hex as "0x..." not "0..."
And the # I really used was ...47 not ...20.
That's 0x2f that I recognise -- not 39 that I don't recognise.
I don't speak octal - forgot all that in 50 years, it's deprecated.
But that number is bigger than 47 -- 57 not 39 either.
And I guess I speak binary, but not here.

Anyway what you put on the table makes some sense -- but where did the 
"x" go?
Since when are "0" and "0x" equivalent?
And 39?
Should I believe 2f shows up as 39 because the "f" doesn't fit (bad carry)?
So there is more to the dotted-quad format than meets the eye than a 
"preceding zero".

We are not there yet...
The rule just is(?) *don't* use fixed 3-digit numbers --> *drop* the 
leading zeros.
No reason -- just a rule?

I did make an even bigger boo-boo though.  In re-checking out the above 
I discovered that F-10 *does act the same* as Etch on this IP.  I don't 
know how I missed it before.  It may be limited to the "pointtopoint" IP 
>    Anyway, try entering an IP address in hex, like 0x9a434b63
> ifconfig eth0:99 0x9a434b63
> eth0:99   Link encap:Ethernet  HWaddr 00:10:dc:38:fa:d9
>           inet addr:  Bcast:  Mask:
>           UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
>           Interrupt:16 Base address:0xe000
>    9a434b63 hex ==
>    Fun stuff :)
>    Enjoy!
>       --- Jay WB8TKL
So what about the equivalence of "login" and "ssh" sessions?


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