Strange ip address

[david walcroft]

Scot L. Harris wrote:
> On Sun, 2004-05-09 at 00:16, david walcroft wrote:
> 
>>Hi, It does not worry me or effect using the net - but just
>>inquiring why - are the IP's from 'ifconfig' and 'netstat -nr'
>>different.
>>
>>ifconfig
>>
>>inet addr:203.45.135.80  Bcast:255.255.255.255  Mask:255.255.252.0
>>
>>netstat -nr
>>
>>[david at reddwarf david]$ sudo netstat -nr
>>Kernel IP routing table
>>Destination     Gateway         Genmask         Flags   MSS Window  irtt 
>>Iface
>>192.168.0.0     0.0.0.0         255.255.255.0   U         0 0          0 
>>eth2
>>203.45.132.0    0.0.0.0         255.255.252.0   U         0 0          0 
>>eth1
>>169.254.0.0     0.0.0.0         255.255.0.0     U         0 0          0 
>>eth2
>>127.0.0.0       0.0.0.0         255.0.0.0       U         0 0          0 lo
>>0.0.0.0         203.45.132.1    0.0.0.0         UG        0 0          0 
>>eth1
>>
>>   Thanks  david
> 
> 
> ifconfig is showing you the settings on your machines interface.  The
> netstat -rn command shows you the routing table on your machine. 
> Because you have a 22 bit subnet subnet mask the actual network has a
> usable address range from 203.45.132.1 to 203.45.135.254.  (or a
> possible 1022 hosts).
> 
> Your machines address happens to be towards the end of the usable IP
> address range (203.45.135.80).
> 
> You also have a second ethernet card on network 192.168.0.0/24, your
> ifconfig information does not include your machines IP address on that
> network.  
> 
> The 169.254.0.0 address I believe is for automatic configuration of
> interfaces.  I have seen this on windows boxes which fail to get their
> DHCP configurations.  I think there is an RFC which describes this. 
> Have not read it so can not provide any details on it.
> 
> The 127.0.0.0 is for your local loop back address.
> 
> And the 0.0.0.0 is for your default gateway.  In this case your machine
> is configured to send packets to 203.45.132.1 (which appears to be your
> networks default gateway) if the destination IP address does not fall
> within one of the other local networks defined on your system.
> 
> 
Thanks Scot,just what I needed and I always have the 169.254.0.0 address it must
be my ISP,I'll have to read up on subnet masks.

   david