Subnet Mask

[jasont]

I have a class c range of 192.168.1.0-192.168.1.254
my subnet mask is 255.255.255.0
if i changed the subnet mask on the default gateway to
255.255.0.0 would i get more ip addresses and how would
it affect my network if i did that. The reason i ask is
because my network is out of ip addresses and i need the
fastest, most easiest solution to fix this because i just
got a shipment of 50 pc's and i dont have any ip
addresses to give.

 

[jasont]

sorry for that last post i mean could i use the subnet of
255..0.0.0 and the ip address of 10.0.0.1

 

[Herb Martin]

could i use the subnet mask of 10.0.0.1

No, because that isn't a subnet mask -- looks like a
host on the 10-net.

You can use the ten-net but again you will have to
change the mask on each host to something shorter
than /24 or 255.255.255.0.

You can add a second subnet to the same wire (and
change no masks) but you will have to deal with the
routing issue if hosts must communicate.

You can put 192.168.0.1 and 192.168.1.1 addresses
on the router then use both the 192.168.0 and 192.168.1
subnets (or any other pair/set you wish.) Mask 255.255.255.0

Half the clients get 192.168.0.x addresses, the other half
get 192.168.1.y addresses -- it's called a "multinet" because
you have multiple subnets on one physical segment.

You must also configure a superscope if you use a DHCP
server to hand out these address ranges.

Use two nets with a router -- it's the right thing to do.

 

[Herb Martin]

sorry for that last post i mean could i use the subnet of
255..0.0.0 and the ip address of 10.0.0.1

Yes, (see previous message) but that still requires changing
ever current host (address AND subnet).

Use a router and two segments -- it's the right thing to do.

 

[jasont]

thanx herb i think i am goin to use a pc as a router,
configure rounting and remote access and go from there.
Do u think that that is is the best idea

 

[Karl]

If you are on a Class C IP address (192.168.xxx.xxx) and you are out of
IP's, then you really need to re-evaluate your network. Move into a Class B
which will suffice to give you quite a number of IP's for your network so
that you have room to grow in the future unless you want to repeat this
issue again.

 

[Herb Martin]

thanx herb i think i am goin to use a pc as a router,
configure rounting and remote access and go from there.
Do u think that that is is the best idea

I think that's a great idea. You need a server for RRAS
routing, or just enable it in the registry for workstations
in this simple case.

Your gateway to the Internet (and perhaps your other
stations) will need to have a STATIC route to this router
to find the second subnet.

 

[Herb Martin]

If you are on a Class C IP address (192.168.xxx.xxx) and you are out of

Actually using 192.168.x.x as he asked or as you show above is the
equivalent of using a Class B -- class are largely defunct and are
really meaningless for privately adminstered ranges like this -- use
any mask that makes sense.

Also, he probably doesn't want to just keep adding (hundreds of)
clients to the same network rather than adding a router (or two.)

 

[Karl]

You would want to start using switches in your network to divide your
network into smaller chunks. Unless this is a rather large company, I do
not see the need to use multiple routers when switches do pretty much all
the work you want. And if you incorporate VLAN, even better!

But what do I know, I don' even have my CCNA yet But from I understand,
using more switches and fewer routers in most situations is pretty common.
VLAN makes a big difference too!

 

[Herb Martin]

But what do I know, I don' even have my CCNA yet But from I
understand,

using more switches and fewer routers in most situations is pretty common.
VLAN makes a big difference too!

VLAN switches ARE "routers" -- technically they are
a hybrid form of Switch which includes the capability
of both Routers and Bridges.

You are actually just following the "use Switch" mantra by
rote -- understand it first, apply it second.