Re: default route question.

["Matthew L. Shobe" <mls@shobe.org>]

On Fri, Sep 05, 2003 at 05:17:44PM -0600, KroNiC~BSD wrote:
> A question about the default route, i must be reading this incorrect.
> 
> TraNsLaToR# ifconfig ep2
> ep2: flags=8863<UP,BROADCAST,NOTRAILERS,RUNNING,SIMPLEX,MULTICAST> mtu
> 1500
>         address: 00:60:97:22:5c:3c
>         media: Ethernet 10baseT
>         inet6 fe80::260:97ff:fe22:5c3c%ep2 prefixlen 64 scopeid 0x6
>         inet 12.210.147.136 netmask 0xfffff800 broadcast 255.255.255.255
> 
> now my routing table:
> 
> TraNsLaToR# route show
> Routing tables
> 
> Internet:
> Destination      Gateway            Flags 
> default          12-210-144-1.clien UG     
>
> how can my default route be 
> 
> default          12-210-144-1.clien UG 
> 
> when my address on the ex. interface is not in the same subnet?
> 
> if my ex. interface addy is 
> 
> 12.210.147.136 ...should not my default GW be on the 12.210.147.0
> network.
> i would have thought it would be .1 as in 12.210.147.1
> 
> anyways am i reading this wrong?

Yes.

$ ipcalc 12.210.147.136/21

Address:   12.210.147.136        00001100.11010010.10010 011.10001000
Netmask:   255.255.248.0 = 21    11111111.11111111.11111 000.00000000
Wildcard:  0.0.7.255             00000000.00000000.00000 111.11111111
=>
Network:   12.210.144.0/21       00001100.11010010.10010 000.00000000 (Class A)
Broadcast: 12.210.151.255        00001100.11010010.10010 111.11111111
HostMin:   12.210.144.1          00001100.11010010.10010 000.00000001
HostMax:   12.210.151.254        00001100.11010010.10010 111.11111110
Hosts/Net: 2046

For further information:
_TCP/IP Illustrated, Volume 1_; Stevens, 1994
ISBN 0-201-63346-9
-- 
mls