Expanding Subnet

We are running out of IP address for the standard 255 255 255 0 range.
If I re subnet my DHCP to 255 255 254 0 will I have to change every device
that is using a static IP?
ex servers
printers
access points





Will Sellers

hi,
yes you have to do that.
for 128.128.0.0 /23 you will have range IP's from 128.128.0.1-128.128.1.254
so for IP's (128.128.0.1-128.128.0.254)/23 and (128.128.0.1-128.128.0.254)/24
they will se each other with no problem, the problem will apear on
(128.128.0.1-128.128.0.254)/24 that's IP's will not see any on the IP's
(128.128.1.1 -128.128.1.254)/23

--
Dragos CAMARA
MCSA Windows 2003 server


"Will Sellers" wrote:

> We are running out of IP address for the standard 255 255 255 0 range.
> If I re subnet my DHCP to 255 255 254 0 will I have to change every device
> that is using a static IP?
> ex servers
> printers
> access points
>
>
>
>

Create a new 254 host network and put a router between them. IP segments
need to stay below 250-300 hosts for ethernet to remain efficient. This is
the case for Ethernet even if it wasn't running TCP/IP and was using IPX/SPX
or something else. Ethernet functions by broadcasting,..the more hosts, the
more broadcasts,...the more broadcasts the less effiecient. It isn't about
just PCs,...routers, switches, and other network devices generate a load on
the wire as well.

Using masks that are lower bit than /24 (more than 254 hosts) are for
supernetting over backbones where it is then broken down into smaller IP
segment at a down stream router.

--
Phillip Windell
www.wandtv.com

The views expressed, are my own and not those of my employer, or Microsoft,
or anyone else associated with me, including my cats.
-----------------------------------------------------

"Will Sellers" <(E-Mail Removed)> wrote in message
news:RLSBi.4498$2p5.2396@trndny05...
> We are running out of IP address for the standard 255 255 255 0 range.
> If I re subnet my DHCP to 255 255 254 0 will I have to change every
> device that is using a static IP?
> ex servers
> printers
> access points
>
>
>

This also means you won't have to reconfigure any of your existing
equipment. You just add a LAN Router into the system and create the new
segment off of the router's other interface. The new segment at first would
have nothing on it at all. You would then move Hosts to the new segment
over time as needed and according to if there is a logical reason to move
any old Hosts to the new segment.

You can't take as much time as you want to finish it from that point.

--
Phillip Windell
www.wandtv.com

The views expressed, are my own and not those of my employer, or Microsoft,
or anyone else associated with me, including my cats.
-----------------------------------------------------


"Phillip Windell" <(E-Mail Removed)> wrote in message
news:(E-Mail Removed)...
> Create a new 254 host network and put a router between them. IP segments
> need to stay below 250-300 hosts for ethernet to remain efficient. This is
> the case for Ethernet even if it wasn't running TCP/IP and was using
> IPX/SPX or something else. Ethernet functions by broadcasting,..the more
> hosts, the more broadcasts,...the more broadcasts the less effiecient. It
> isn't about just PCs,...routers, switches, and other network devices
> generate a load on the wire as well.
>
> Using masks that are lower bit than /24 (more than 254 hosts) are for
> supernetting over backbones where it is then broken down into smaller IP
> segment at a down stream router.
>
> --
> Phillip Windell
> www.wandtv.com
>
> The views expressed, are my own and not those of my employer, or
> Microsoft, or anyone else associated with me, including my cats.
> -----------------------------------------------------
>
> "Will Sellers" <(E-Mail Removed)> wrote in message
> news:RLSBi.4498$2p5.2396@trndny05...
>> We are running out of IP address for the standard 255 255 255 0 range.
>> If I re subnet my DHCP to 255 255 254 0 will I have to change every
>> device that is using a static IP?
>> ex servers
>> printers
>> access points
>>
>>
>>
>
>

"Phillip Windell" <(E-Mail Removed)> wrote in message
news:%(E-Mail Removed)...
> You can't take as much time as you want to finish it from that point.

Sorry,..typo,...

You **can** take as much time as you want to finish it from that point.

Hmmmm
We currently have one dual channel router that combines 2 T1'S INTO ONE BIG
PIPE.
This router is our gateway.
How would I add another router?

"Phillip Windell" <(E-Mail Removed)> wrote in message
news:%(E-Mail Removed)...
> This also means you won't have to reconfigure any of your existing
> equipment. You just add a LAN Router into the system and create the new
> segment off of the router's other interface. The new segment at first
> would have nothing on it at all. You would then move Hosts to the new
> segment over time as needed and according to if there is a logical reason
> to move any old Hosts to the new segment.
>
> You can't take as much time as you want to finish it from that point.
>
> --
> Phillip Windell
> www.wandtv.com
>
> The views expressed, are my own and not those of my employer, or
> Microsoft, or anyone else associated with me, including my cats.
> -----------------------------------------------------
>
>
> "Phillip Windell" <(E-Mail Removed)> wrote in message
> news:(E-Mail Removed)...
>> Create a new 254 host network and put a router between them. IP segments
>> need to stay below 250-300 hosts for ethernet to remain efficient. This
>> is the case for Ethernet even if it wasn't running TCP/IP and was using
>> IPX/SPX or something else. Ethernet functions by broadcasting,..the more
>> hosts, the more broadcasts,...the more broadcasts the less effiecient.
>> It isn't about just PCs,...routers, switches, and other network devices
>> generate a load on the wire as well.
>>
>> Using masks that are lower bit than /24 (more than 254 hosts) are for
>> supernetting over backbones where it is then broken down into smaller IP
>> segment at a down stream router.
>>
>> --
>> Phillip Windell
>> www.wandtv.com
>>
>> The views expressed, are my own and not those of my employer, or
>> Microsoft, or anyone else associated with me, including my cats.
>> -----------------------------------------------------
>>
>> "Will Sellers" <(E-Mail Removed)> wrote in message
>> news:RLSBi.4498$2p5.2396@trndny05...
>>> We are running out of IP address for the standard 255 255 255 0 range.
>>> If I re subnet my DHCP to 255 255 254 0 will I have to change every
>>> device that is using a static IP?
>>> ex servers
>>> printers
>>> access points
>>>
>>>
>>>
>>
>>
>
>

it's ok you oppinion , but in that case you "moved" all traffic of
servers,printers etc of the new clients throught that router wich can be
worst than the broadcast. Modern switces can limit the broadcast, multicast
and collisions.
--
Dragos CAMARA
MCSA Windows 2003 server


"Phillip Windell" wrote:

> This also means you won't have to reconfigure any of your existing
> equipment. You just add a LAN Router into the system and create the new
> segment off of the router's other interface. The new segment at first would
> have nothing on it at all. You would then move Hosts to the new segment
> over time as needed and according to if there is a logical reason to move
> any old Hosts to the new segment.
>
> You can't take as much time as you want to finish it from that point.
>
> --
> Phillip Windell
> www.wandtv.com
>
> The views expressed, are my own and not those of my employer, or Microsoft,
> or anyone else associated with me, including my cats.
> -----------------------------------------------------
>
>
> "Phillip Windell" <(E-Mail Removed)> wrote in message
> news:(E-Mail Removed)...
> > Create a new 254 host network and put a router between them. IP segments
> > need to stay below 250-300 hosts for ethernet to remain efficient. This is
> > the case for Ethernet even if it wasn't running TCP/IP and was using
> > IPX/SPX or something else. Ethernet functions by broadcasting,..the more
> > hosts, the more broadcasts,...the more broadcasts the less effiecient. It
> > isn't about just PCs,...routers, switches, and other network devices
> > generate a load on the wire as well.
> >
> > Using masks that are lower bit than /24 (more than 254 hosts) are for
> > supernetting over backbones where it is then broken down into smaller IP
> > segment at a down stream router.
> >
> > --
> > Phillip Windell
> > www.wandtv.com
> >
> > The views expressed, are my own and not those of my employer, or
> > Microsoft, or anyone else associated with me, including my cats.
> > -----------------------------------------------------
> >
> > "Will Sellers" <(E-Mail Removed)> wrote in message
> > news:RLSBi.4498$2p5.2396@trndny05...
> >> We are running out of IP address for the standard 255 255 255 0 range.
> >> If I re subnet my DHCP to 255 255 254 0 will I have to change every
> >> device that is using a static IP?
> >> ex servers
> >> printers
> >> access points
> >>
> >>
> >>
> >
> >
>
>
>

"Dragos CAMARA" <(E-Mail Removed)> wrote in message
news:788219DD-77C9-4FFE-896B-(E-Mail Removed)...
> it's ok you oppinion , but in that case you "moved" all traffic of
> servers,printers etc of the new clients throught that router wich can be
> worst than the broadcast.

It won't be worse than broadcast damage. Good quality LAN Routers are not
that slow. It is certainly never going to happen with only 2 subnets with
254 hosts on each side. But you are also supposed to put the printers and
servers into the segment with the Hosts that use them the most. Now Layer3
Switches, which are just switches and routers built into the same case may
be capable of 256 subnets (VLANs) and if you had 254 hosts on each VLAN that
would be 65,024 hosts on a single Router. So yes, that could be a problem.
But most traditional small/meduim business LAN Routers will only have 2 or 4
Ethernet ports with 2-4 subnets.

> Modern switces can limit the broadcast, multicast
> and collisions.

Yes, switches will stop collisions which greatly helps the possible damage
done by broadcasts and a fully switched LAN would not degrade as quicky as
a non-switched LAN if there were too many hosts, but they do nothing for
broadcasts,...unless they are Layer3 Switches,..but then "Layer3" makes them
Routers. They are LAN Routers and Switches built into the same physical
box,..but you still have to logically separate the two different roles when
designing the LAN.

I guess my larger point of this whole thing is that LANs should be carefully
planned out for this kind of stuff,..a guy should not just roll back the
mask a bit or two and keep throwing hosts at it. Proper guidlines and
pinciples should always be followed even if you don't think you need them at
the moment,...you'll need them eventually,...it will catch up to you.


--
Phillip Windell
www.wandtv.com

The views expressed, are my own and not those of my employer, or Microsoft,
or anyone else associated with me, including my cats.
-----------------------------------------------------

"Will Sellers" <(E-Mail Removed)> wrote in message
news:Br9Ci.616$3R5.305@trnddc05...
> Hmmmm
> We currently have one dual channel router that combines 2 T1'S INTO ONE
> BIG PIPE.
> This router is our gateway.
> How would I add another router?

LAN Routers and Internet Routes have nothing to do with each other.

You'd have to buy a LAN Router (or Layer3 Switch and learn VLANing).

Your existing LAN is already *one* segment.
One interface of the LAN router Plugs into your LAN.

The other interface(s) of the LAN Router plugs into the "new"
segment,...which in its simplest form is just a matter of plugging a new
switch into this. Whatever hosts plug into this new switch are on the new
segment (assuming your properly configured TCP/IP for this new segment).

The original Segment remains untouched except for changing the Default
Gateway. Everything has to use the LAN Router as the Default Gateway,...the
LAN Router itself, in turn, uses the Internet Sharing Device (whatever that
is) as its Default Gateway.

<Internet>
|
[Internet Router]
|
<Public Segment>
|
[Internet Sharing Device (Firewall?)]
|
<original LAN Segment>
|
[LAN Router]
|
<new LAN segment>

If your Internet Router is also the current Default Gateway of the LAN then
that device is serving multiple purposes within the same hardware box and
you have *no* public segment. This is not how T1 lines are typically
done,..this is how home-user broadband technologies are done (DSL &
CableTV).
You would have this:

<Internet>
|
[Internet Router & NAT Firewall]
|
<original LAN Segment>
|
[LAN Router]
|
<new LAN segment>

--
Phillip Windell
www.wandtv.com

The views expressed, are my own and not those of my employer, or Microsoft,
or anyone else associated with me, including my cats.
-----------------------------------------------------

hi,
i agree with you, but what i wanted to do was to check that isn't enought to
put a router there, even you put a router or just modify the mask you have to
solve some problems wich for sure are different for each approach and have to
balance pro and cons of what you wanna to do, how many workstations, what
traffic is there, what switches etc.
--
Dragos CAMARA
MCSA Windows 2003 server


"Phillip Windell" wrote:

> "Dragos CAMARA" <(E-Mail Removed)> wrote in message
> news:788219DD-77C9-4FFE-896B-(E-Mail Removed)...
> > it's ok you oppinion , but in that case you "moved" all traffic of
> > servers,printers etc of the new clients throught that router wich can be
> > worst than the broadcast.
>
> It won't be worse than broadcast damage. Good quality LAN Routers are not
> that slow. It is certainly never going to happen with only 2 subnets with
> 254 hosts on each side. But you are also supposed to put the printers and
> servers into the segment with the Hosts that use them the most. Now Layer3
> Switches, which are just switches and routers built into the same case may
> be capable of 256 subnets (VLANs) and if you had 254 hosts on each VLAN that
> would be 65,024 hosts on a single Router. So yes, that could be a problem.
> But most traditional small/meduim business LAN Routers will only have 2 or 4
> Ethernet ports with 2-4 subnets.
>
> > Modern switces can limit the broadcast, multicast
> > and collisions.
>
> Yes, switches will stop collisions which greatly helps the possible damage
> done by broadcasts and a fully switched LAN would not degrade as quicky as
> a non-switched LAN if there were too many hosts, but they do nothing for
> broadcasts,...unless they are Layer3 Switches,..but then "Layer3" makes them
> Routers. They are LAN Routers and Switches built into the same physical
> box,..but you still have to logically separate the two different roles when
> designing the LAN.
>
> I guess my larger point of this whole thing is that LANs should be carefully
> planned out for this kind of stuff,..a guy should not just roll back the
> mask a bit or two and keep throwing hosts at it. Proper guidlines and
> pinciples should always be followed even if you don't think you need them at
> the moment,...you'll need them eventually,...it will catch up to you.
>
>
> --
> Phillip Windell
> www.wandtv.com
>
> The views expressed, are my own and not those of my employer, or Microsoft,
> or anyone else associated with me, including my cats.
> -----------------------------------------------------
>
>
>