[nsp] Prefix 0.0.0.0/1

[Bill Manning]

 default, 0.0.0.0/0, is distinctly different than two supernets.
 given the nature of the 0.0.0.0 network, defining sub/supernets 
 with that the origin may not give you what you want.




% Hi Bill,
% 
% >  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.
% 
% What would be the difference from using a default route 0.0.0.0/0 and two
% supernets of 0.0.0.0/1 and 128.0.0.0/1? Wouldn't they cause the same effect?
% Would there be any other implications?
% 
% thanks,
% sonny
% >
% >
% >
% > % 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/
% > % >
% > %
% > %
% > % _______________________________________________
% > % 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/
% > %
% >
% >
% > --
% > --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).
% >
% 
% 


-- 
--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).