[PLUG] it gets weirder - was Linux 7.2 printer problem solved

J.A. Henshaw jeff at jhenshaw.com
Thu Mar 21 17:42:03 UTC 2002


Michael Rasmussen wrote:

> I got curious about why the configuration of 192.168.200.081 doesn't work.
> Poked around on the machine for a bit and found that `ifconfig
> 192.168.0.001` works as does `ifconfig 192.168.0.071` 
> 
> Then a bit of shell:
> 
>  for i in 6 7 8 9
>  do    
>    for j in 0 1 2 3 4 5 6 7 8 9
>    do       
>       ifconfig eth0 down
>       echo trying 0$i$j >> conflog 
>       ifconfig eth0 192.168.200.0$i$j >>conflog 2>&1
>       echo trying $i$j >> conflog
>       ifconfig eth0 192.168.200.$i$j >> conflog 2>&1
>    done
>  done
> 
> And the results show an error whenever a digit larger than 7 is in the
> specified address:
> 
>  trying 067
>  trying 67
>  trying 068
>  192.168.200.068: Unknown host
>  ifconfig: '--help' gives usage information.
>  ...
>  trying 077
>  trying 77
>  trying 078
>  192.168.200.078: Unknown host
>  ifconfig: `--help' gives usage information.
>  trying 78
> 
> So Robert, the real answer to your question is:
> 
> an IP address ending in .081 is invalid - because the leading 0 tells the
> software to interpret the number in octal.  In octal only digits 0-7 are
> valid.  For that matter and address of say 192.168.081.001 would also be
> invalid. Because the 3rd octet is not a valid octal number.  
> 
> You could also try something like `ifconfig eth0 192.168.0x081.1` which
> would result in an address of 192.168.129.1.
> 
> Thanks for the interesting problem.  
> 
> --  
>   Michael Rasmussen - Network Engineer, Columbia Management
>   voice:  971-925-6723  cell:  503-807-1447  rasmussenm at columbiafunds.com
>   <mailto:rasmussenm at columbiafunds.com> http://www.columbiafunds.com
> 


Michael,  Thanks for the interesting analysis as well!

Give that man a raise!!

I hope YOU didn't sign any oppressive employment contracts 
re open source.... :)

jH


> 
> 


-- 
Democracy is when two wolves and a sheep vote on what they 
will have for lunch.





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