Real reason for DHCP superscopes

[gthuey]

Hey everyone! I am trying to figure out the value of DHCP superscopes
and I know I am running into a mental block.

I totally understand what the intentions are, concerning multinets. I
also understand when they are NOT needed (ie scopes per subnet with ip
helper/boot relay on routers).

Well lets say we have a 192.168.1.x network and we are running out of
ip's so we decided to add another network 192.168.2.x to give some more
ips.

So according to MS I make my nifty superscope and add both of those
scopes to this scope. Great, but so what? Here is the crux of the
issue why would a superscope really be needed. Couldn't I just leave
the two scopes as independent scopes. They would both service the same
broadcast network, right?

I know I am missing one small piece of this puzzle, so any
enlightenment would be greatly appreciated. My problem is that I think
I am trying to read more into the superscope technology.

Thanks again for everyone's time.

 

[Phillip Windell]

Hey everyone! I am trying to figure out the value of DHCP superscopes
and I know I am running into a mental block.

They are for Multi-Netting, which is running multiple subnets on the same
physical "wire",...but not to be confused with VLANs. VLANs logically
separate the "wire" via frame-tagging so VLAN's are not multi-netting. In
fact VLAN's kind of make multi-nets obsolete. The actual legitament need
for a Superscope is very very rare.


--
Phillip Windell [MCP, MVP, CCNA]
www.wandtv.com
-----------------------------------------------------
Understanding the ISA 2004 Access Rule Processing
http://www.isaserver.org/articles/ISA2004_AccessRules.html

Microsoft Internet Security & Acceleration Server: Guidance
http://www.microsoft.com/isaserver/techinfo/Guidance/2004.asp
http://www.microsoft.com/isaserver/techinfo/Guidance/2000.asp

Microsoft Internet Security & Acceleration Server: Partners
http://www.microsoft.com/isaserver/partners/default.asp
-----------------------------------------------------

 

[Guest]

nothing to do with super scopes but what I did in this situation was simply
change the mask to /23 and exclude the network and broadcast addresses(4).
This worked great, it was simple and seamless and still using single scope
and now I have 510 available addresses.This way they still all see each other.

 

[Guest]

correction 508 not 510

nothing to do with super scopes but what I did in this situation was simply
change the mask to /23 and exclude the network and broadcast addresses(4).
This worked great, it was simple and seamless and still using single scope
and now I have 510 available addresses.This way they still all see each other.

 

[Phillip Windell]

It will work that way. However Ethernet can become inefficient after about
250-300 hosts,...so that makes the /24 the perfect size. If you actually
had 510 active real hosts on the same segment it probably wouldn't work very
well.

--
Phillip Windell [MCP, MVP, CCNA]
www.wandtv.com
-----------------------------------------------------
Understanding the ISA 2004 Access Rule Processing
http://www.isaserver.org/articles/ISA2004_AccessRules.html

Microsoft Internet Security & Acceleration Server: Guidance
http://www.microsoft.com/isaserver/techinfo/Guidance/2004.asp
http://www.microsoft.com/isaserver/techinfo/Guidance/2000.asp

Microsoft Internet Security & Acceleration Server: Partners
http://www.microsoft.com/isaserver/partners/default.asp

 

[Guest]

Thanks for your reply Phillip,

1.) Does this limitation still apply to a GB network?
2.) Does this mean that all scopes are limited? Is this the reason why we
should subnet? What about very large networks with thousands of users in the
same office.

Steve

It will work that way. However Ethernet can become inefficient after about
250-300 hosts,...so that makes the /24 the perfect size. If you actually
had 510 active real hosts on the same segment it probably wouldn't work very
well.

--
Phillip Windell [MCP, MVP, CCNA]
www.wandtv.com
-----------------------------------------------------
Understanding the ISA 2004 Access Rule Processing
http://www.isaserver.org/articles/ISA2004_AccessRules.html

Microsoft Internet Security & Acceleration Server: Guidance
http://www.microsoft.com/isaserver/techinfo/Guidance/2004.asp
http://www.microsoft.com/isaserver/techinfo/Guidance/2000.asp

Microsoft Internet Security & Acceleration Server: Partners
http://www.microsoft.com/isaserver/partners/default.asp
-----------------------------------------------------

nothing to do with super scopes but what I did in this situation was simply
change the mask to /23 and exclude the network and broadcast addresses(4).
This worked great, it was simple and seamless and still using single scope
and now I have 510 available addresses.This way they still all see each other.

 

[Phillip Windell]

I'm sure gigabit can handle more. In the CCNA material I got that from the
100mbps LAN was the frame of reference. However loading the Gig Net heavier
just means it will run slower, so that kind of defeats the purpose of the
the faster speed. So I would still try to follow the same guidlines.
There isn't a "hard rule",.. just principles,...so if it does what you want
it to do and as well as you want it to do it,...then go ahead.

--
Phillip Windell [MCP, MVP, CCNA]
www.wandtv.com
-----------------------------------------------------
Understanding the ISA 2004 Access Rule Processing
http://www.isaserver.org/articles/ISA2004_AccessRules.html

Microsoft Internet Security & Acceleration Server: Guidance
http://www.microsoft.com/isaserver/techinfo/Guidance/2004.asp
http://www.microsoft.com/isaserver/techinfo/Guidance/2000.asp

Microsoft Internet Security & Acceleration Server: Partners
http://www.microsoft.com/isaserver/partners/default.asp
-----------------------------------------------------

Thanks for your reply Phillip,

1.) Does this limitation still apply to a GB network?
2.) Does this mean that all scopes are limited? Is this the reason why we
should subnet? What about very large networks with thousands of users in the
same office.

Steve

It will work that way. However Ethernet can become inefficient after about
250-300 hosts,...so that makes the /24 the perfect size. If you actually
had 510 active real hosts on the same segment it probably wouldn't work very
well.

--
Phillip Windell [MCP, MVP, CCNA]
www.wandtv.com
-----------------------------------------------------
Understanding the ISA 2004 Access Rule Processing
http://www.isaserver.org/articles/ISA2004_AccessRules.html

Microsoft Internet Security & Acceleration Server: Guidance
http://www.microsoft.com/isaserver/techinfo/Guidance/2004.asp
http://www.microsoft.com/isaserver/techinfo/Guidance/2000.asp

Microsoft Internet Security & Acceleration Server: Partners
http://www.microsoft.com/isaserver/partners/default.asp
-----------------------------------------------------

nothing to do with super scopes but what I did in this situation was simply
change the mask to /23 and exclude the network and broadcast addresses(4).
This worked great, it was simple and seamless and still using single scope
and now I have 510 available addresses.This way they still all see

each
other.

:

Hey everyone! I am trying to figure out the value of DHCP superscopes
and I know I am running into a mental block.

I totally understand what the intentions are, concerning multinets. I
also understand when they are NOT needed (ie scopes per subnet with ip
helper/boot relay on routers).

Well lets say we have a 192.168.1.x network and we are running out of
ip's so we decided to add another network 192.168.2.x to give some more
ips.

So according to MS I make my nifty superscope and add both of those
scopes to this scope. Great, but so what? Here is the crux of the
issue why would a superscope really be needed. Couldn't I just leave
the two scopes as independent scopes. They would both service the same
broadcast network, right?

I know I am missing one small piece of this puzzle, so any
enlightenment would be greatly appreciated. My problem is that I think
I am trying to read more into the superscope technology.

Thanks again for everyone's time.