How to configure DHCP Service on SBS, more specifically, how to hand out subnet mask.
I need help in setting up the DHCP Service on SBS 2000 Server. Specifically the Scope Option that hands out the subnet mask to the client workstations. I utilize a class B network (172.25.x.x). The server hands out the IP addresses okay, but then the work station appears to default the subnet mask to 255.255.0.0. I would like the DHCP Server to hand the workstation a SM of 255.255.255.0. I would think this might be a Scope Option, but I cannot determine which one it is. I see a couple options like "Perform Mask Discovery" and "Mask Supplier Option", but I'm not sure if either of these is what I am looking for. I would experiment, but I don't want to distrub the 40 users who are presently logged in. No one is having any trouble, but I can't ping the work stations remotely and I think this is the reason.
myin68
If there's a firewall configured on the PCs it could prevent the ping reply.
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I don't believe this is a firewall issue. But assuming it was, what settings or procedure would you suggest I make to the Windows Firewall on the workstation?
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In any case, my original question was, in short, what Scope Option in SBS DHCP Service Settings allows me hand out a specific subnet mask to DHCP clients?
By defining your scope as a class B network 172.25.x.x you be default define the subnet mask as 255.255.0.0. Altering the netmask to 255.255.255.0 on the client desktops, will result in a lack of connectivity. This will happen because the default gateway and the broadcast address wiill not be correct.
i.e. for 172.25.0.2 netmask 255.255.0.0 has a default gateway of 172.25.0.1 with the broadcast address of 172.25.255.255 while for an allocated ip of 172.25.0.2 with netmask 255.255.255.0 the default gateway will remain 172.25.0.1 but the broadcast address will be 172.25.0.255.
An alternate designation for the default gateway and broadcast address might be part of the scope's options, not sure whether the netmask is an option as well.
i.e. for 172.25.0.2 netmask 255.255.0.0 has a default gateway of 172.25.0.1 with the broadcast address of 172.25.255.255 while for an allocated ip of 172.25.0.2 with netmask 255.255.255.0 the default gateway will remain 172.25.0.1 but the broadcast address will be 172.25.0.255.
An alternate designation for the default gateway and broadcast address might be part of the scope's options, not sure whether the netmask is an option as well.
What is the actual IP address, Subnet mask and Default Gateway of your SBS server you are setting DHCP up on?
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Again, my original question was, what Scope Option in SBS DHCP Service Settings allows me hand out a specific subnet mask to DHCP clients? To answer this question, one would have to be familure with setting up DHCP services on a Windows 2000 server (or Small Business Server). What IP address, subnet mask, and GW we have on the server, and what class network we have is imaterial. Anyone know anything about DHCP Service Scope Options? To get there in Windows 2000 Server go to <Computer Mangement><Services and Applications><DHCP><Scope>
I've looked in our DCHP server (2003) and I couldn't find where to set the subnet mask either. I think the only time you can define your subnet mask is when you first create your scope. You probably have to delete your current scope, and recreate it with the subnet mask you want. Your users will get the new settings after they reboot.
What your IP address is on your DHCP server is relevent meyco.
I use 172.16.XXX.XXX and my DHCP servers hand out the 255.255.255.0 subnet to all of my clients. It depends on how your DHCP server's network is set up in the first place which is why I asked.
I use 172.16.XXX.XXX and my DHCP servers hand out the 255.255.255.0 subnet to all of my clients. It depends on how your DHCP server's network is set up in the first place which is why I asked.
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I have three offices, each with its own DHCP Server. The offices are 172.25.10.x, 172.25.20.x and 172.25.30.x. The each handout IP addresses in the range specified 172.25.xx.150-199, were xx is the location 10, 20, 30. In anycase, the DHCP services always handout subnet 255.255.0.0. It needs to be 255.255.255.0. I use Linksys VPN Routers (RV-082) to connect the offices together. If I statically set IP and SM to 255.255.255.0 on a machine (such as the main server and location 10), everyone can see the machine from any office. But if I use DHCP, it hands out 255.255.0.0 and that machine can only be seen at it's home location, not by any of the other locations.
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Maybe it would be best to just use static IPs for all the work stations; probably would help keep track of them better; but I would still like to figure this out.
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Arnold, I think you may be the winner of this puzzle.
First, the netmask on the interface is 255.255.255.0. The DHCP Server hands out IP address, gateway, and DNS, but not netmask. That is my problem. Go back and read comment on 02.13.2008 wherein I am trying to figure out how to handout netmask. Your suggesting that 172 space hands out 255.255.0.0 by default does not gell with the comment posted by EnclosAdmin on 02.18.2008. I have thought about using the Linksys VPN to hand out DHCP, but I prefer not to decentralize control through the Small Business Server.
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All that aside, it appears, after reading KB300429, that the netmask is defined at the time we create the scope in DHCP. It appears that is only time you can define the netmask. It appears I cannot change it once the scope is setup. Now the bonus question; what will happen if I delete the current scope and create a new one. Will my connected users loose connectivity. Or should I create a new one first, then delete the old one? I don't want my phone ringing off the hook when I do this.
First, the netmask on the interface is 255.255.255.0. The DHCP Server hands out IP address, gateway, and DNS, but not netmask. That is my problem. Go back and read comment on 02.13.2008 wherein I am trying to figure out how to handout netmask. Your suggesting that 172 space hands out 255.255.0.0 by default does not gell with the comment posted by EnclosAdmin on 02.18.2008. I have thought about using the Linksys VPN to hand out DHCP, but I prefer not to decentralize control through the Small Business Server.
H O W E V E R:
All that aside, it appears, after reading KB300429, that the netmask is defined at the time we create the scope in DHCP. It appears that is only time you can define the netmask. It appears I cannot change it once the scope is setup. Now the bonus question; what will happen if I delete the current scope and create a new one. Will my connected users loose connectivity. Or should I create a new one first, then delete the old one? I don't want my phone ringing off the hook when I do this.
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Thanks Arnold.
meyco, my last comment "I've looked in our DCHP server (2003) and I couldn't find where to set the subnet mask either. I think the only time you can define your subnet mask is when you first create your scope. You probably have to delete your current scope, and recreate it with the subnet mask you want. Your users will get the new settings after they reboot." is exactly what you said last. Is that where you got the idea?
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I took a chance and just deleted the existing scope while everyone was online. I created a new scope with subnet mask I wanted and no one ever noticed the change. Everything is working perfectly now.