Simple version

 

Load-balancing your DHCP has been well documented, but the matter of synchronizing your IP reservations has always the fly in the ointment. But no more.

To export DHCP reservations, from the source server:

netsh dhcp server [ip address] scope [scope address] dump>reserv.txt

Open up ‘reserv.txt’ in a text editor, do a Find->Replace for the source server IP, change to the destination server IP. Trim out everything in the file except for the reservations themselves.

On the destination server, make sure your scope is already created, and run the following command:

netsh exec C:\reserv.txt

Tada. The only problem is that as your add more and more reservations, you’ll need to add them to each server that you are load balancing. It’s easier to do that than to do another export.

found at Link

continuation of topic

The problematic scenario is the following:

There are two DHCP servers serving the same set of subnets. For each of the subnets which is being served by both the servers there are two scopes one for each server. The scopes are configured in a way that the active address range in one is in the exclusion range of the other. This way we make sure that a particular IP address is not distributed independently of each other. Now there is a small problem if there are reservations. If the admin has configured the reservations in only one of the scopes then he is on for a surprise. The surprise is that the client for whom you have configured the reservation might get a dynamic IP address from the other DHCP server. This can happen in case the DISCOVER sent by the client reaches the server which does not have reservations first. Thus the essential reason for having a reservation is defeated.

The proper way to handle this scenario is: First configure the scope such that the active address range for both the DHCP servers in question is mutually exclusive. Then write a netsh script for the reservations. This script file (let’s call it reservations.txt) would contain for each reservation an entry like:

dhcp server 10.0.0.1 scope 10.0.0.0 add   reservedip 11.0.0.1 <MAC ADDRESS>

Now run this script in the first server 10.0.0.1 by typing:

Netsh exec reservations.txt

After this has been done, you might want to use a word processor to replace the IP address of the server 10.0.0.1 to the IP address of the second DHCP server (say 10.0.0.2).

Once this replacement has been done, you can run the script in the second server. Actually the scripts for both the servers can be run from any place from which there is network connectivity to the DHCP servers. This is because almost most of the operations done through netsh is remotable.

Now for the tough part. If you do have two scopes like what I have mentioned and you did not duplicate the reservations then you have to do the following:

On the DHCP server where you have configured the reservations, you can execute this command for each of the scopes from which you need to export the reservations.

netsh dhcp server <serverIPAddress> scope <scopeAddress>  dump>dump.txt

This will dump all the configuration settings for this scope. At the bottom of the dumped text file, you can see the reservations being dumped. Just copy this reservation settings to a new file say “exportedreserv.txt”.

Append to this file exportedreserv.txt the reservation settings from each of the other scopes.

Now on the target machine, do a

netsh exec exportedreserv.txt

You should be done by now. I know it is not completely automatic, but it does save a lot of effort.

found at Link

A repyl on this on how to automate it was :

Thanks!  This got me started doing more resarch on netsh and I found a way to fully automate this process with a batch file and 2 free utilities (grep.exe and sed.exe, alternative )  In my environment I was worried about 2 dhcp servers getting out of sync.  So this script will purge all reservations from the 2nd server every night, and import the reservations from the 1st server.  Maybe someone else will find it useful.

REM #– Dump current DHCP configurations –#

netsh dhcp server \\server1 dump > dhcp_dump.txt

netsh dhcp server \\server2 dump > dhcp_purge.txt

REM #– In the purge file, pull out the reservation details and change “add” to “delete” –#

grep reservedip dhcp_purge.txt | sed.exe “s/Add/delete/” > dhcp_purge-reservations.txt

REM #– Purge reservations on the second dhcp server –#

netsh exec dhcp_purge-reservations.txt

REM #– In the dump file pull out the reservation details and change server IPs. –#

grep reservedip dhcp_dump.txt | sed.exe “s/<server1 IP>/<server2 IP>/” > dhcp_new-reservations.txt

REM #– Import the new reservations into the second dhcp server –#

netsh exec dhcp_new-reservations.txt

Microsoft VBS script

Reservation Manager – A tool to manage reservations

Reservation Manager:
Reservations are a critical feature in the DHCP server. Reservations’ are generally used for centralized static IP address assignment for critical machines. This way the IP address of the critical machines which serves critical functions in the network will not have dynamically assigned IP address which can change over time. The reservation manager is a tool which will help solve typical reservation-related problems which the network admins might face. More often than not this tool tries to automate problems to recurring customer problems. It tries to solve the following reservation-related problems:
1) Migrating reservations from one DHCP Server to another on specific subnets.
As a general best-practice, reservations must be duplicated across all DHCP servers serving the same subnet. This particular functionality addresses this best-practice. Without this the admin has to manually dump reservations from one server to another. This command takes 3+ arguments. The first argument tells the destination DHCP server IP address to which the reservations must be copied to. The second argument identifies the IP Address of the source DHCP server. The last argument is either ‘all’ or identifies the first scope address on which this operation has to be performed. The third argument can be followed by n number of arguments which identify the different subnet’s to which this operation has to be performed.
Example:
cscript rmanager.vbs Rmanager –migrate 10.0.0.1 11.0.0.1 all
This command will copy all reservations in all scopes from the server 10.0.0.1 to the server 11.0.0.1.
cscript rmanager.vbs Rmanager –migrate 10.0.0.1 11.0.0.1 12.0.0.0 10.0.0.0 11.0.0.0
This command will copy reservations from the scopes 12.0.0.0 10.0.0.0 and 11.0.0.0 from the server 10.0.0.1 to 11.0.0.1.
For this command to work properly the specified scope/scopes should be present in both the servers. An error message will be printed for those scopes for which this condition is not met. Also for those reservations which cannot be added successfully for whatever reason, an error is printed. Also for every successfully migrated reservation, it can be printed.
In addition to this, this command can also take an additional preview switch which will just print the action which will be taken and not actually take the action. This is especially useful when the admin wants to review the action before doing it.
Example:
cscript rmanager.vbs Rmanager –migrate 10.0.0.1 11.0.0.1 all –preview out.txt
cscript rmanager.vbs Rmanager –migrate 10.0.0.1 11.0.0.1 12.0.0.0 10.0.0.0 11.0.0.0 –preview out.txt

2) Synchronizing reservations on 2 DHCP servers on specific subnets.
As already mentioned, it is a general best-practice for reservations must be duplicated across all DHCP servers serving the same subnet. This particular functionality addresses this best-practice in a more subter way. Instead of copying reservations from one server to another, this option lets the admin to synchronize the reservation lists between two servers. The arguments for this switch is exactly similar to that of the migrate switch. This command also has an optional preview switch.
Example:
cscript rmanager.vbs Rmanager –sync 10.0.0.1 11.0.0.1 all
This command will sync all reservations in all scopes from the server 11.0.0.1 to the server 10.0.0.1.
cscript rmanager.vbs Rmanager –sync 10.0.0.1 11.0.0.1 12.0.0.0 10.0.0.0 11.0.0.0
For this command to work properly the specified scope/scopes should be present in both the servers. An error message will be printed for those scopes for which this condition is not met. Also for those reservations which cannot be added successfully for whatever reason, an error is printed. Also for every successfully migrated reservation, it can be printed.
In addition to this, this command can also take an additional preview switch which will just print the action which will be taken and not actually take the action. This is especially useful when the admin wants to review the action before doing it.
Example:
cscript rmanager.vbs Rmanager –sync 10.0.0.1 11.0.0.1 all –preview out.txt
cscript rmanager.vbs Rmanager –sync 10.0.0.1 11.0.0.1 12.0.0.0 10.0.0.0 11.0.0.0 –preview out.txt

3) Dumping leases on specific subnets.
This command dumps the leases for a specific scope and server into a human-editable text file. The file will contains several lines each of which corresponds to a single lease. A lease is represented by IP address and MAC address. The exact utility of this command will be exposed once you see the next section.
Example:
cscript rmanager.vbs Rmanager -dumplease out.txt 120.0.0.1 all
The above command dumps all leases in all scopes in the server 120.0.0.1 to a text file called “out.txt”
cscript rmanager.vbs Rmanager -dumplease out.txt 120.0.0.1 10.0.0.0 11.0.0.0
The above command dumps all leases in scopes 10.0.0.0 and 11.0.0.0 in the server 120.0.0.1 to a text file called “out.txt”

4) MakeReservation switch.
This switch tries to create reservations on a given DHCP server from the information present in a given input file. The input file contains several lines of info. Each line corresponds to a single reservation. Each reservation is represented by IP address and MAC address pair. The format of this input file is exactly the same as the output file of the -dumplease switch.
Example:
cscript rmanager.vbs Rmanager -makereservation 120.0.0.1 out.txt
This command will create reservations out of information present in the file out.txt in the server 120.0.0.1.

Based on the -dumplease and -makereservation switch, some interesting possibilities arise. What is possible is the following scenario: An admin has an active DHCP server which has a couple of scopes. Initially there are no reservations in any of these scopes. Thus all the subnets corresponding to these scopes have dynamic addresses. In the environment any machine which is plugged into the these subnets will get a dynamic IP address from the DHCP server. Now to restrict the access of the network to those machines that are already connected to the network, the admin can do the following.
cscript rmanager.vbs Rmanager -dumplease out.txt 120.0.0.1 all
cscript rmanager.vbs Rmanager -makereservation 120.0.0.1 out.txt
These two commands intends to convert every active lease in a given DHCP server identified by an IP address in a given set of scopes identified by a list of scope addresses into reservations. Once this is done, the admin also has to make sure that the whole address space in the given scope in the DHCP server are excluded. This operation is thus particularly relevant to those admins who might want to move from a pure Dynamic IP address assignment to a more controlled purely reservation oriented address assignment. This way the admin can keep track of who is getting IP addresses and can limit the network access to those clients who already have an IP address.
The first command Rmanager -dumplease <filename> <Scope Identifiers> will dump all the active leases in the specified server and scope to a text file. This text file will have pair of IP address and MAC addresses. The second command Rmanager –makereservation <ServerIdentifier> <filename> will take the file which is generated by the first command and create reservations corresponding to them. The idea behind separating these two actions is to make sure that the admin gets a chance to edit the file generated by the first command before proceeding to the second. Also we want to support scenarios where the admin can just create the file and use it to run the second command directly.

In the attachment (See the link at the end of this post), Find the RManager.vbs .You need to extract the contents of the zip file into a separate folder and run it from there. The zip file should contain two files: rmanager.vbs and help.txt.

 If you are not able to get it, Cut-copy-paste the following into a file named rmanager.vbs. Also copy the contents of the documentation help.txt

Run it by typing “cscript rmanager.vbs”

X———————–Begin Paste———————X

call start()
dim scopes
dim synccount
dim argerror
dim iparray
dim macarray
dim finaliparray
dim finalmacarray
dim m
dim args

sub start()

args=0
synccount=0
argerror=0
if(wscript.arguments.count=0) then
wscript.echo “enter the command”
exit sub
end if

for i=0 to wscript.arguments.count-1
if(i=0) then
str=wscript.arguments.item(i)
else
str=str&” “&wscript.arguments.item(i)
end if
next

str1=split(str)

‘show error if nothing is entered————

if (not isarray(str1)) then
wscript.echo “Error: unrecongnized or incomplete command line.”
call helpfile()
exit sub
end if
‘checking if the command is Rmanager or not

if(strcomp(“Rmanager”,str1(0))<>0) then
wscript.echo “Error: unrecongnized or incomplete command line.”
call helpfile()
exit sub
end if

‘checking for different cases after Rmanager
if(ubound(str1)=0) then
wscript.echo “Error: unrecongnized or incomplete command line.”
call helpfile()
exit sub
end if
select case str1(1)

case “-migrate”

call migrate(str1)

case “-sync”

call migrate(str1)
if(argerror=1) then
exit sub
end if
synccount=1
a=str1(2)
str1(2)=str1(3)
str1(3)=a
call migrate(str1)

case “-dumplease”

call dump(str1)

case “-makereservation”

call makereservation(str1)

case “/?”

call helpfile()

case else
wscript.echo “Error: unrecongnized or incomplete command line.”
call helpfile()

end select

‘delete the scopefile that is created during the program

set fso = createobject(“Scripting.FileSystemObject”)
if(fso.fileexists(“scopefile.txt”))then
fso.deletefile(“scopefile.txt”),true
end if
end sub
‘ function for dumplease

sub dump(str1)

‘if improper arguments are entered show error

if ubound(str1)<4 then
wscript.echo “Error: unrecongnized or incomplete command line.”
call helpfile()
exit sub
end if

filename = str1(2)
set fso = createobject(“Scripting.FileSystemObject”)
Set outfile = fso.CreateTextFile(filename)
outfile.close

p=checkserver(str1(3))

if p=0 then
wscript.echo “server “&str1(3)&” not present or is entered wrongly”
exit sub
end if

serverarray = makescopearray(scopes)

if not isarray(serverarray) then
wscript.echo “no scopes in server “&str1(3)
exit sub
end if

if (strcomp(str1(4),”all”)=0) then

if(ubound(str1)=4) then
scope = serverarray
else
wscript.echo “improper arguments”
end if

else

for i = 4 to ubound(str1)
if(isscope(str1(i),serverarray)) then
redim preserve scope(i-4)
scope(i-4)=str1(i)
else
wscript.echo “scope “& str1(i) &” is not present in server “&str1(3)
exit sub
end if
next
end if
‘scope contains all the scopes entered
if not isarray(scope) then
wscript.echo “no scopes in the server “&str1(3)
else
if scope(0)=”” then
wscript.echo “no scopes in the server “&str1(3)
else
set wshell = CreateObject(“WScript.Shell”)

for i = 0 to ubound(scope)
set obj = wshell.exec(“netsh dhcp server “&str1(3)&” scope “&scope(i)&” show clients”)
clients = obj.stdout.readall()
if(instrrev(clients,”Command completed successfully.”)=0) then
exit sub
end if
call makeclients(clients,str1(2))
next
end if
end if
if args = 0 then
else
wscript.echo “the ipaddress and macaddress pair are in file “&filename
end if
end sub

’the following procedure outputs the ip and corresponding mac addresses(active leases) into the file – ‘filename’…it takes the output string clients that we get after executing the command shoe clients

sub makeclients(clients,filename)

set fso = createobject(“Scripting.FileSystemObject”)
Set scopefile = fso.CreateTextFile(“scopefile.txt”)
scopefile.writeline(clients)
scopefile.close

Set scopefile = fso.OpenTextFile(“scopefile.txt”)
do While not scopefile.AtEndOfStream   ‘reading line by line and checking for the string “Total No. of Scopes”

line = scopefile.ReadLine

if(instr(line,”No of Clients”)=1) then
str = split(line)

t=str(4)        ’taking no. of clients into t
exit do

end if

loop

scopefile.close

t=cint(t)

if t=0 then
wscript.echo “no clients in the scope “&str(ubound(str))

exit sub
end if
args=args+1
Set scopefile = fso.OpenTextFile(“scopefile.txt”)
for i= 1 to 8
scopefile.skipline
next

set outfile = fso.opentextfile(filename,8)

for i=0 to t-1
line=scopefile.readline

str= split(line)

if (instr(line,”INACTIVE”)<>0) then
d=0
for l=0 to ubound(str)
if(str(l)=””) then
else
if d=3 then
exit for
else
d=d+1
end if
end if
next

outfile.write(str(0))
for size = 1 to 18-(len(str(0)))
outfile.write(” “)
next

outfile.writeline(trim(replace(str(l),”-“,””)))

else
d=0
for l=0 to ubound(str)
if(str(l)=””) then
else
if d=4 then
exit for
else
d=d+1
end if
end if
next
outfile.write(str(0))
for size = 1 to 18-(len(str(0)))
outfile.write(” “)
next

outfile.writeline(trim(replace(str(l),”-“,””)))
end if
next
outfile.close
end sub

sub makereservation(str1)

if ubound(str1)<>3 then
wscript.echo “Error: unrecongnized or incomplete command line.”
call helpfile()
exit sub
end if

server = str1(2)
filename = str1(3)

set fso = createobject(“Scripting.FileSystemObject”)
if(not fso.fileexists(filename))then
wscript.echo “file “&filename&” not present”
exit sub
end if

k = checkserver(server)
if k=0 then
wscript.echo “server “&server&” is not present or may have been entered wrongly”
exit sub
end if

scopearray=makescopearray(scopes)       ‘scopes is the output string obtained after executing show scope command for given server

set handle = fso.opentextfile(filename)

Dim ipaddress
Dim macaddress
t=0
do while not handle.atendofstream

line=trim(handle.readline)
line=replace(line,” “,””)
if line=”” then

else
strarray=split(line)

p=0

for k=0 to ubound(strarray)
if strarray(k)=”” then

else

if p=0 then
ipaddress=trim(strarray(k))
else if p=1 then
macaddress = trim(strarray(k))
end if
end if
p=p+1
‘wscript.echo Replace(ipaddress, ” “, “”)
‘wscript.echo macaddress
end if
next

if p<>2 then
wscript.echo “improper format of file”
exit sub
end if

redim preserve iparray3(t)
redim preserve macarray3(t)
iparray3(t)=ipaddress
macarray3(t)=macaddress
t=t+1
end if
loop
handle.close

if not isarray(iparray3) then
wscript.echo “there is nothing in the file”
exit sub
end if

dim arr
redim arr(t-1)

for i = 0 to ubound(scopearray)

set iprange = fso.createtextfile(“iprangefile.txt”)
iprange.close
arraysize = 0
dim iparray1
redim iparray1(0)
redim macarray1(0)

set wshell = CreateObject(“WScript.Shell”)
set obj = wshell.exec(“netsh dhcp server “&server&” scope “&scopearray(i)&” show iprange”)
range = obj.stdout.readall()

set iprange = fso.opentextfile(“iprangefile.txt”,8)
iprange.writeline(range)
iprange.close
set iprange = fso.opentextfile(“iprangefile.txt”)

for p=0 to 5
iprange.skipline
next
line1=iprange.readline
line2=split(line1)

count=0

for j=0 to t-1

k = checkiprange(line2(3),line2(13),iparray3(j))

if k = 1 then

redim preserve iparray1(arraysize)
redim preserve macarray1(arraysize)
iparray1(arraysize) = iparray3(j)
macarray1(arraysize) = macarray3(j)
arraysize = arraysize + 1
arr(j)=1
else if k=2 then
wscript.echo “the ip address “&iparray3(j)&” is not valid”
fso.deletefile(“iprangefile.txt”),true
exit sub
end if
end if
next

iprange.close
if isarray(iparray1) and not iparray1(0)=”” then

call addreservation(server,scopearray(i),iparray1,macarray1)

if (finaliparray(0)=””) then

else
for l=0 to ubound(finaliparray)
set obj = wshell.exec(“netsh dhcp server “&server&” scope ” &scopearray(i)& ” add reservedip “&finaliparray(l)&” “&finalmacarray(l) )
outp =  obj.stdout.readall()
if(instr(outp,”Command completed successfully.”)<>0) then
wscript.echo “added reservation “&finaliparray(l)& ” “&finalmacarray(l)&” to server “&server&” in scope “&scopearray(i)
else

wscript.echo “The specified IP address “&finaliparray(l)& ” or hardware address “& finalmacarray(l)& ” is either not proper or is being used by another client.”
end if
next
end if

end if
redim iparray1(0)
redim macarray1(0)

next

set handle = fso.opentextfile(filename)
for i=0 to ubound(arr)
str=trim(handle.readline)

if(arr(i)=0) then
line=split(str)

wscript.echo “The ipaddress “&iparray3(i)&” is not present in any scope”
end if
next
handle.close
fso.deletefile(“iprangefile.txt”),true
end sub

sub addreservation(server,scopestr,iparraysource,macarraysource)

redim finaliparray(0)
redim finalmacarray(0)
set wshell = CreateObject(“WScript.Shell”)
set obj = wshell.exec(“netsh dhcp server “&server&” scope ” &scopestr& ” show reservedip” )
outpdest = obj.stdout.readall()

call makeipandmacarray(outpdest)
iparraydest = iparray
macarraydest = macarray

‘ remove common ip and mac pair between the two servers for the given scope

if(not isarray(iparraydest)) then
finaliparray=iparraysource
finalmacarray=macarraysource

else
k=0

for i = 0 to ubound(iparraysource)
flag=0
for j=0 to ubound(iparraydest)
if(iparraysource(i)=iparraydest(j) and macarraysource(i)=macarraydest(j)) then
flag=1
exit for
end if
next

if flag=1 then

if synccount = 0 and m=0 then

wscript.echo “reservation “&iparraysource(i)&” “&macarraysource(i)&” is already present on server “&server
end if
else

redim preserve finaliparray(k)
redim preserve finalmacarray(k)
finaliparray(k)=iparraysource(i)
finalmacarray(k)=macarraysource(i)
k=k+1
end if
next
end if

end sub

function checkiprange(ip1,ip2,ip3)

str2=split(ip1,”.”)
str3=split(ip2,”.”)
str4=split(ip3,”.”)
if ubound(str4)<>3 then
checkiprange=2
exit function
end if

dim string

if cint(str2(0))<=cint(str4(0)) and cint(str4(0))<=cint(str3(0)) then
if cint(str2(1))<=cint(str4(1)) and cint(str4(1))<=cint(str3(1)) then
for i=2 to 3
if(cint(str2(i))>=0 and cint(str2(i))<10) then
string1=string1&”00″&str2(i)
else if(cint(str2(i))>=10 and cint(str2(i))<100) then
string1=string1&”0″&str2(i)
end if
end if
next
for i=2 to 3
if(cint(str3(i))>=0 and cint(str3(i))<10) then
string2=string2&”00″&str3(i)
else if(cint(str3(i))>=10 and cint(str3(i))<100) then
string2=string2&”0″&str3(i)
end if
end if
next
for i=2 to 3
if(cint(str4(i))>=0 and cint(str4(i))<10) then
string3=string3&”00″&str4(i)
else if(cint(str4(i))>=10 and cint(str4(i))<100) then
string3=string3&”0″&str4(i)
end if
end if
next

if(cint(string1)<=cint(string3) and cint(string3)<=cint(string2)) then
checkiprange=1
else
checkiprange=0
end if

else
checkiprange=0
end if
else
checkiprange=0
end if
end function

sub helpfile()

set fso = createobject(“Scripting.FileSystemObject”)
set help = fso.OpenTextFile(“help.txt”)

do while not help.atendofstream

wscript.echo (help.readline)

loop

end sub

‘ this function will return 1 if the scope(scopestr) is present in the given server(serverarray….this is an array of server scopes)(be it source or destination)…else 0

function isscope(scopestr,serverarray)

l=0
for i=0 to ubound(serverarray)
if(strcomp(scopestr,serverarray(i))=0) then
l=1
exit for
end if
next

isscope=l

end function

’this function will check if the server entered as argument is present or not(or rather entered correctly or not)

function checkserver(str1)
dim wshell

dim pos1

set wshell = CreateObject(“WScript.Shell”)
set obj = wshell.exec(“netsh dhcp server “&str1&” show scope”)

scopes = obj.stdout.readall()

pos1=instr(scopes,”Command completed successfully.”)      ‘if the string is present, the command has executed succesfully

if(pos1<>0) then
checkserver=1
else
checkserver=0
end if

end function

’this function takes as argument the output string that we get after the command show scope is executed and returns
’the array of all scopes present in the server

function makescopearray(scopes)

set fso = createobject(“Scripting.FileSystemObject”)
Set scopefile = fso.CreateTextFile(“scopefile.txt”)
scopefile.writeline(scopes)           ‘writing output string to a file
scopefile.close

Set scopefile = fso.OpenTextFile(“scopefile.txt”)
do While not scopefile.AtEndOfStream   ‘reading line by line and checking for the string “Total No. of Scopes”

line = scopefile.ReadLine

if(instr(line,”Total No. of Scopes”)=2) then
str = split(line)
t=str(ubound(str)-1)        ’taking no. of scopes into t
exit do
end if

loop

scopefile.close

t=cint(t)      ‘converting string to integer

if t=0 then      ‘if no scopes are present

makescopearray=””
else

Set scopefile = fso.OpenTextFile(“scopefile.txt”)
for i=1 to 5
scopefile.skipline     ‘skipping first five lines
next
for i=0 to t-1
str3=trim(scopefile.readline)

str3 = split(str3,” “)

redim preserve serverscope(i)
serverscope(i)=str3(0)     ‘adding scopes to array serverscope

next
makescopearray = serverscope    ‘returning the array to calling function
scopefile.close
end if
end function

 

‘function to take reservations from source server and add to destination server for a given scope

sub reservedip(sourceadd,destadd,scopestr,filename,command)

dim outp
set wshell = CreateObject(“WScript.Shell”)
set obj = wshell.exec(“netsh dhcp server “&sourceadd&” scope ” &scopestr& ” show reservedip” )
outpsource = obj.stdout.readall()

call makeipandmacarray(outpsource)
iparraysource = iparray
macarraysource = macarray

if(not isarray(iparraysource)) then
wscript.echo “no reservations in the scope “&scopestr&” on the server “&sourceadd
exit sub
end if
if(m=1 or m=2) then

set fso = createobject(“Scripting.FileSystemObject”)
Set outfile = fso.openTextFile(filename,8)

for i=0 to ubound(iparraysource)
outfile.writeline(“netsh dhcp server “&destadd& ” scope ” &scopestr& ” add reservedip ” &iparraysource(i)& ” ” & macarraysource(i))
next
outfile.close
exit sub
end if
call addreservation(destadd,scopestr,iparraysource,macarraysource)

‘now finaliparray and finalmacarray contain only the unique ip and mac addresses

if (not isarray(finaliparray) or finaliparray(0)=””) then
if ((m=1 or m=2)) then
if (strcomp(command,”-migrate”)=0 or (strcomp(command,”-sync”)=0 and synccount=1)) then
wscript.echo”output is in file “&filename
end if
end if

exit sub
end if

t=ubound(finaliparray)

set wshell = CreateObject(“WScript.Shell”)
for i=0 to t
set obj = wshell.exec(“netsh dhcp server “&destadd&” scope ” &scopestr& ” add reservedip ” &finaliparray(i)& ” ” & finalmacarray(i))
outp =  obj.stdout.readall()
if(instr(outp,”Command completed successfully.”)) then
wscript.echo “added reservation “&finaliparray(i)& ” “&finalmacarray(i)&” to server “&destadd&” in scope “&trim(scopestr)
else

wscript.echo “The specified IP address “&finaliparray(i)& ” or hardware address “& finalmacarray(i)& ” is being used by another client.”
end if

next

if ((m=1 or m=2)) then
if (strcomp(command,”-migrate”)=0 or (strcomp(command,”-sync”)=0 and synccount=1)) then
wscript.echo”output is in file “&filename
end if
end if
end sub

sub makeipandmacarray(outp)
redim iparray(0)
redim macarray(0)

set fso = createobject(“Scripting.FileSystemObject”)
Set scopefile = fso.CreateTextFile(“scopefile.txt”)
scopefile.writeline(outp)
scopefile.close

Set scopefile = fso.openTextFile(“scopefile.txt”)

do While not scopefile.AtEndOfStream
line = scopefile.ReadLine
if(instr(line,”No of ReservedIPs”)=1) then
str = split(line)
t=str(4)         ’taking no. of reservations into t
exit do
end if
loop

scopefile.close

if t=0 then
iparray = “”
macarray = “”
exit sub

else
Set scopefile = fso.openTextFile(“scopefile.txt”)

for i=1 to 7
scopefile.skipline
next

for i=1 to t
redim preserve iparray(i-1)
redim preserve macarray(i-1)
string1=split(trim(scopefile.readline))

iparray(i-1)=string1(0)
macarray(i-1)=replace(string1(ubound(string1)),”-“,””)
next
end if
scopefile.close

end sub

sub migrate(str1)

if ubound(str1)<4 then        ‘ ensures that the command entered has required no. of arguments
wscript.echo “Error: unrecongnized or incomplete command line.”
call helpfile()
argerror=1
exit sub
end if
dim k

k = checkserver(str1(2))               ‘checking if the source server exists or not…
‘or if they are entered correct or not
if k=0 then
wscript.echo “server “&str1(2)& ” not present or is entered wrongly”
argerror=1
exit sub
end if

scopes1 = scopes

k = checkserver(str1(3))
if k=0 then
wscript.echo “server “&str1(3)& ” not present or is entered wrongly”
argerror=1
exit sub
end if

scopes2 = scopes

‘comes here if both servers are entered correctly

sourcescope = makescopearray(scopes1)      ‘sourcescope here has all scopes from source server
if(isarray(sourcescope)) then     ‘checking if there are any scopes in source server
else
wscript.echo “no scopes present on server “&str1(2)
argerror=1
exit sub
end if

bound=ubound(str1)
if(strcomp(str1(4),”all”)=0) then           ‘checking if the option “all” is entered
if(bound>4 and bound<7) then
if(strcomp(str1(5),”-preview”)<>0) then
argerror=1
wscript.echo “Error: unrecongnized or incomplete command line.”
call helpfile()
exit sub
else
if(bound=6) then
filename = str1(6)
m=2
else
m=1
filename = “output.txt”
end if
end if
else
m=0
end if

scope=sourcescope       ‘scope array now contains all the scopes from source server
else

if(strcomp(str1(bound),”-preview”)=0) then
m=1
filename = “output.txt”
else if(strcomp(str1(bound-1),”-preview”)=0) then
m=2
filename = str1(bound)
else
m=0
end if
end if

p=0
for i = 4 to ubound(str1)-m      ’this is the case when scopes are entered as arguments
if(isscope(str1(i),sourcescope)) then     ‘checking if the given scope is present in source server
redim preserve scope(p)       ‘if present then add the scope entered to the array ‘scope’
scope(p)=str1(i)
p=p+1
else
if(synccount=0) then         ‘if the scope entered is not present in the source server
wscript.echo “scope “&str1(i)& ” is not present in the server “&str1(2)
end if
end if
next
end if

erase sourcescope       ‘freeing the space allocated to sourcescope
if(not isarray(scope)) then      ‘checking if the scope array has some scopes or not
argerror=1
exit sub
end if

destscope = makescopearray(scopes2)     ‘destscope has all scopes from destination server
if(isarray(destscope)) then      ‘checking if there are scopes present on destination server

else
wscript.echo “no scopes present on server “&str1(3)
argerror=1
exit sub
end if

if(m=1 or m=2) then
if(synccount=0) then
set fso = createobject(“Scripting.FileSystemObject”)
set outfile = fso.createtextfile(filename)
outfile.close
end if
end if

for i=0 to ubound(scope)

if(isscope(scope(i),destscope)) then     ‘checking if scopes are present on destination server or not

call reservedip(str1(2),str1(3),scope(i),filename,str1(1)) ’this will take reservations in the given scope from source server and output add reservedip(destination) command to a file

else

wscript.echo “scope “&scope(i)& ” not present in server “&str1(3)
end if
next
if (m=1 or m=2) then
if(strcomp(str1(1),”-migrate”)=0 or (strcomp(str1(1),”-sync”)=0 and synccount=1)) then
wscript.echo”output is in file “&filename

end if
end if
end sub

X———————–End Paste———————X

And here is a more formal looking help:
USAGE:
Rmanager  /?
-migrate <source server> <destination server> <all|<list of scopes>>
[-preview [filename]]
-sync <server1> <server2> <all | <list of scopes>>
[-preview [filename]]
-dumplease <filename> <server> <all | <listof scopes>>
-makereservation <server> <filename>

Options:
/?     display this help message
-migrate     copies reservations from all or the specified
scopes from source to destination server…if
preview is specified, it shows the commands that
will be executed, in the output file
-sync            synchronises reservations between two servers for
all or the specified scopes….if preview is
specified, it shows the commands that will be
executed, in the output file
-dumplease          outputs the ip and macaddresses of all clients in
the given server for the given scopes
-makereservation    adds reservations for the ip and mac address pairs
from the given file into the given server

Examples:
> cscript rmanager.vbs Rmanager -migrate 120.0.0.1 120.0.0.2 all
….copies reservations in all scopes from server 120.0.0.1
to server 120.0.0.2
> cscript rmanager.vbs Rmanager -sync 120.0.0.1 120.0.0.2 120.0.0.0
….synchronises reservations between the two servers
120.0.0.1 and 120.0.0.2 for the scope 120.0.0.0
> cscript rmanager.vbs Rmanager -dumplease out.txt 120.0.0.1 all
…dumps all clients’ ip and mac addresses into out.txt
> cscript rmanager.vbs Rmanager -makereservation 120.0.0.1 out.txt
…takes ip and mac address pairs from the file out.txt and
makes reservation on the server 120.0.0.1

found at link