DHCP full

[jasont]

i am out of addresses can someone point me in the right
direction. my first scope is 192.168.1.1-192.168.1.254
what can i make the 2nd scope. very confused
any help is appreciated

 

[Herb Martin]

i am out of addresses can someone point me in the right

direction. my first scope is 192.168.1.1-192.168.1.254
what can i make the 2nd scope. very confused
any help is appreciated

Couple of ideas:

Put in a router (or equivalent switch -- layer 3) and
separate some of the machines to another segment/subnet.

While there have been single networks (broadcast domains)
must larger than 250 hosts, today that is close to an upper
limit with the low cost of hardware.

Second method (if you must): Add another scope to the DHCP
server, for the next subnet, and superscope the two regular scopes.

Now you can lease addresses from two subnets to the same
segment -- it's called a "multi-net".

You will still have to deal with routing just as you would were it
to distinct segments for the two subnets.

 

[Ace Fekay [MVP]]

In

Couple of ideas:

Put in a router (or equivalent switch -- layer 3) and
separate some of the machines to another segment/subnet.

While there have been single networks (broadcast domains)
must larger than 250 hosts, today that is close to an upper
limit with the low cost of hardware.

Second method (if you must): Add another scope to the DHCP
server, for the next subnet, and superscope the two regular scopes.

Now you can lease addresses from two subnets to the same
segment -- it's called a "multi-net".

You will still have to deal with routing just as you would were it
to distinct segments for the two subnets.

He could also change the subnet mask to 255.255.252.0. It will give him an
extra bit for the hosts that will bump up the possible host count to 512
hosts instead of 254.

So it will be:
192.168.1.1 - 192.168.1.511

--
Regards,
Ace

Please direct all replies to the newsgroup so all can benefit.

Ace Fekay, MCSE 2000, MCSE+I, MCSA, MCT, MVP
Microsoft Windows MVP - Active Directory

 

[John Sy]

192.168.x.x is a subnet commonly usd for internal network
use. Given that, can you simply go to subnet mask
255.255.0.0 and you can then use the range 192.168.1.1 to
192.168.254.254. Easiest solution I can think of.

 

[Herb Martin]

He could also change the subnet mask to 255.255.252.0. It will give him an

extra bit for the hosts that will bump up the possible host count to 512
hosts instead of 254.

So it will be:
192.168.1.1 - 192.168.1.511

I thought DCHP wouldn't allow you to increase the subnet
size after the scope was created?

Did I misremember or did they fix this in a new version/SP?

 

[Kenneth Porter]

how would i change the subnet mask, and could i do this
while the machines and users are in production, or would
i have to wait until evryone leaves

It would only affect machines needing to talk those that, using the old
mask, would be in different subnets. In other words, the servers in the old
netblock and the workstations in the new one.

 

[jasont]

huh

-----Original Message-----


It would only affect machines needing to talk those that, using the old
mask, would be in different subnets. In other words, the servers in the old
netblock and the workstations in the new one.

 

[Ace Fekay [MVP]]

In

huh

Kenneth said, it'll work either way, but recommended to do it after hours,
like any other major change.

Change the subnet mask on your servers by going into their IP properties and
change the mask there.

In DHCP, you would have to delete the scope and recreate it with the new
mask.




--
Regards,
Ace

Please direct all replies to the newsgroup so all can benefit.

Ace Fekay, MCSE 2000, MCSE+I, MCSA, MCT, MVP
Microsoft Windows MVP - Active Directory

 

[Herb Martin]

Nah, he would have to recreate it. Just offering a suggestion to increase

Well, if he recreates the scope he loses the current lease
database. At that point, renewing every client is a very good
idea.

the host count. ANother guy, John said to make the subnet mask a /16. Either
way, it'll work. Just the /16 may not work if there are remote locations
that may overlap. Depends on the network topology.

 

[Herb Martin]

I may well be Windows Server 2003 deluded but can you not simply export

the current configuration using NETSH, edit the resulting text file and
import (in order to at least preserve any detailed configuration). This
may well (I haven't researched it) lose the current lease database but
isn't that issue handled by the majority of uplevel clients by
performing a gratuitous ARP against the offered address before accepting
it (or so I thought/hoped .

Yes, I hinted at the "gratuitous" (I would say "courtesy") test (it's not
just
an ARP because it must work across routers, right?

The courtesy duplicate IP test done by the DHCP server is not something
one can depend upon however -- it's there for mistakes, to try to prevent
harm if things do go bad but it isn't to be counted upon.

One issue is the machine that is using the address but happens to be offline
or just doesn't reply in time. (Also, it would only be suitable for same
subnet or if we are doing more than arp.)

BTW, I have always presumed something akin to a DHCP-UDP "ping".

 

[Dean Wells [MVP]]

Inline ...

--
Dean Wells [MVP / Windows platform]
MSEtechnology
[[ Please respond to the Newsgroup only regarding posts ]]
R e m o v e t h e m a s k t o s e n d e m a i l

Yes, I hinted at the "gratuitous" (I would say "courtesy") test (it's not
just
an ARP because it must work across routers, right?

Not quite, an address provided by a DHCP server will be subnet specific
thus the ARP approach is sufficient.

The courtesy duplicate IP test done by the DHCP server is not something
one can depend upon however -- it's there for mistakes, to try to prevent
harm if things do go bad but it isn't to be counted upon.

One issue is the machine that is using the address but happens to be offline
or just doesn't reply in time. (Also, it would only be suitable for same
subnet or if we are doing more than arp.)

Timed out, yes! Offline, it depends on what we define as "Offline" ...
but in many cases, no, as the client will attempt to renew the address
when it comes back online.

BTW, I have always presumed something akin to a DHCP-UDP "ping".

My apologies, I'm not sure what you're driving at.

 

[Herb Martin]

Not quite, an address provided by a DHCP server will be subnet specific

thus the ARP approach is sufficient.

You know, I thought we were talking about the
coutesy test run by THE SERVER in DHCP.

Servers do it too.

Still it remains an unreliable method but probably
good enough to get him by in a pinch.

 

[Dean Wells [MVP]]

Ohhh, OK, I'm with you now Herb. That was why I referenced "client" in
my original post ... no problem, your response makes complete sense now.

You are indeed correct that the servers can attempt a ping against any
suitable (as not all lease requests trigger this behavior) potential
offered address prior to the offer but, sadly, this is disabled by
default and, in my experience, frequently remains that way (I would
guess due to little more than a lack of awareness).

As we've already mentioned, the client behavior has been present for
some time now and generally provides a reliable mechanism (using a DHCP
DECLINE) but even these two features combined do not fully mitigate the
potential for duplicate addresses to occur.

My apologies for the confusion.

Dean

 

[Kenneth Porter]

In DHCP, you would have to delete the scope and recreate it with the new
mask.

And were it me, with lots of reservations, I'd dump the state with netsh,
edit the result, then load it back in.

 

[Herb Martin]

My apologies for the confusion.

Not necessary -- you were at least as "right" as I
was, we were talking about to VERY slightly different
things. They were just so related that it kept sounding
the same.

 

[Kenneth Porter]

Inline ...

FYI:

Inline is good, but a sig-dash before the inline comments is bad. A
compliant newsreader considers *everything* below the sig-dash to be the
sig, so quoted material goes before that.

My newsreader (the free Xnews) colored the entire quote in sig color,
instead of coloring the quoted article in quote color and your new text in
normal color.

(Lots of good free newsreaders at http://www.newsreaders.com/ and supported
in news:news.software.readers.)

 

[Dean Wells [MVP]]

Hi Kenneth,

I appreciate the feedback but to be quite honest, I prefer to direct my
attention toward the technical issues at hand rather than concern myself
with the way certain newsreaders display my commentary. In no way do I
intend this post to come across harshly but, like you, I put a great
deal of effort into attempting to voluntarily provide the community with
solutions to problems, automation scripts and general technical detail.
The way in which I provide that information (assuming it's legible) is
little more than a historical preference (Outlook Express) which
provides no facility for color coding (a useful feature I'll grant you).

Based on the time and effort I know you also put into these forums, I
hope you'll understand if I say "I'll endeavor to move the sig.
(assuming that will fix it) but don't punish me when I forget" (which
is highly likely).

My apologies if this causes difficulties when reading my posts ... I
guess you could just filter me (just teasing ... I hope ;-)

Dean

 

[jasont]

wow I am the person who first asked this question and i
got back at least 20 responses, sorry for making evryone
argue, but now i am confused can someone just give me the
best possible way or the way they know it will work. But
it's nice to see people who want to help so much. Thanks
alot for all the resonses. If someone could email me with
a reponse that would be great thanks again

-----Original Message-----
Hi Kenneth,

I appreciate the feedback but to be quite honest, I prefer to direct my
attention toward the technical issues at hand rather than concern myself
with the way certain newsreaders display my commentary. In no way do I
intend this post to come across harshly but, like you, I put a great
deal of effort into attempting to voluntarily provide the community with
solutions to problems, automation scripts and general technical detail.
The way in which I provide that information (assuming it's legible) is
little more than a historical preference (Outlook Express) which
provides no facility for color coding (a useful feature I'll grant you).

Based on the time and effort I know you also put into these forums, I
hope you'll understand if I say "I'll endeavor to move the sig.
(assuming that will fix it) but don't punish me when I forget" (which
is highly likely).

My apologies if this causes difficulties when reading my posts ... I
guess you could just filter me (just teasing ... I hope ;-)

Dean

--
Dean Wells [MVP / Windows platform]
MSEtechnology
[[ Please respond to the Newsgroup only regarding posts ]]
R e m o v e t h e m a s k t o s e n d e m a i l

#[email protected]:


FYI:

Inline is good, but a sig-dash before the inline comments is bad. A
compliant newsreader considers *everything* below the

sig-dash to be
the

sig, so quoted material goes before that.

My newsreader (the free Xnews) colored the entire quote in sig color,
instead of coloring the quoted article in quote color

and your new
text in

normal color.

(Lots of good free newsreaders at

http://www.newsreaders.com/ and

 

[Herb Martin]

BTW, it's not just coloring that the sig-dash affects; when quoting a

message with a sig-dash, a good newsreader removes the old sig. Were I to
quote your (highly useful) message, all the information you worked to
provide would get chopped off. (It's rare that one responds to another's
sig, so there's no reason to include it in a quoted response.)

It's possible he doesn't understand the term "sig-dash" -- I have been
at this stuff about as long as anyone (at least before signatures were
popular on the Internet or for that matter the Internet was popular
among the populace <grin>) and *I* didn't know it was a convention.

I learned something.

Just a thought. You guys might be talking past each other.

BTW, the reason I use Xnews, and not the many other choices available, is
Xnews' article scoring feature. It lets me assign scores both positive and

So Xnews is the answer? I have a love/hate relationship with Outlook
Express.

I really like the format, threads, rules, etc. -- I hate the way it locks up
or
multitasks so poorly, uses the disk drive so inefficiently, etc.

Weirdest thing, if you "ignore" a message, it puts a BIG HIGHLIGHT on
it, sorts them right under the Watched messages, and then downloads those
message (headers) to ignore them UGGGH.

 

[Dean Wells [MVP]]

LOL ... thanks Herb. I am familiar with sig-dash (but I certainly wasn't
aware that many news readers used it so extensively), it's simply
Outlook's use of it that makes the posting of inline commentary a pain
(phrased another way, I guess I'm too lazy to cut and paste ;-).

<Sigh> ... I'll keep trying!

Dean