[nsp] Prefix 0.0.0.0/1

[Bill Manning]

 0.0.0.0/1  is a whole lot of address space.
 you might want to revisit the CIDR RFCs and RFC 1860.
 In there you will find that a /1 is 2048 million addresses.
 Then you may wish to review draft-manning-dsua-08.txt,
 which talks to the unique nature of the network 0.0.0.0

 and 128.0.0.0/1 will really get you into issues when you hit 
 the top end of the range. the old class D & E space is not 
 treated as regular address space.

 One presumes that your environment is closed.  Doing things like
 this on the Internet will engender the rath of network engineers.



% Hi Robert,
% 
% IOS ver 12.0(10)S. I've tried both commands but no effect. I believe it's
% the way cisco router treats prefix 0.0.0.0 irregardless of the prefixe
% length (whether /0 or /1).
% Am I right? Was hoping someone could enlighten me on this.
% 
% Many thanks and Merry Xmas to everyone..
% 
% sonny
% ----- Original Message -----
% From: "Robert E. Seastrom" <rs@seastrom.com>
% To: "Sonny Franslay" <sonnyfranslay@pacific.net.sg>
% Cc: <cisco-nsp@puck.nether.net>
% Sent: Wednesday, December 25, 2002 3:37 AM
% Subject: Re: [nsp] Prefix 0.0.0.0/1
% 
% 
% >
% > What IOS version are you running?  Is it one that's old enough that
% > "ip subnet-zero" is not on by default?  Try typing that and "ip
% > classless" and retrying...
% >
% >                                         ---Rob
% >
% >
% > Sonny Franslay <sonnyfranslay@pacific.net.sg> writes:
% >
% > > Hi gurus,
% > >
% > > I'm trying to redistribute a static route to dest network 0.0.0.0/1 to
% > > OSPF. However, the prefix is not being seen as an ospf route in the
% > > network table.
% > >
% > > What I want to achieve is to split the default route to two /1 subnet
% > > (0.0.0.0/1 and 128.0.0.0/1). I manage to import the 128.0.0.0/1 routes
% > > into the ospf but not the first half.
% > >
% > > Is there any special requirement in order to do this?
% > >
% > > router ospf 100
% > >  log-adjacency-changes
% > >  redistribute connected subnets
% > >  redistribute static subnets
% > >  network 192.168.92.0 0.0.0.255 area 0
% > > !
% > > ip route 0.0.0.0 128.0.0.0 203.120.92.1
% > > ip route 128.0.0.0 128.0.0.0 203.120.92.1
% > >
% > > seen from the other router:
% > >
% > > >sho ip route ospf
% > >      10.0.0.0/24 is subnetted, 4 subnets
% > > O E2    10.140.140.0 [110/20] via 192.168.92.6, 02:10:11,
% FastEthernet0/0
% > > O E2    10.130.130.0 [110/20] via 192.168.92.6, 02:15:11,
% FastEthernet0/0
% > > O E2    10.20.20.0 [110/20] via 192.168.92.40, 02:27:02, FastEthernet0/0
% > > O E2 192.168.188.0/24 [110/20] via 192.168.92.40, 02:27:02,
% > > FastEthernet0/0
% > >      192.168.1.0/32 is subnetted, 3 subnets
% > > O E2    192.168.1.2 [110/20] via 192.168.92.6, 02:20:11, FastEthernet0/0
% > > O E2    192.168.1.6 [110/110] via 192.168.92.6, 02:25:11,
% FastEthernet0/0
% > > O E2 128.0.0.0/1 [110/20] via 192.168.92.6, 02:00:10, FastEthernet0/0
% > >
% > >
% > > Many thanks in advance
% > >
% > > sonny
% > >
% > > _______________________________________________
% > > cisco-nsp mailing list  cisco-nsp@puck.nether.net
% > > http://puck.nether.net/mailman/listinfo/cisco-nsp
% > > archive at http://puck.nether.net/pipermail/cisco-nsp/
% >
% 
% 
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-- 
--bill

Opinions expressed may not even be mine by the time you read them, and
certainly don't reflect those of any other entity (legal or otherwise).