Member Avatar for JEESco

Hello everyone, i am a newbie so please bare with me cause it's been only 4 days since i started working with windows server 2003,
I've made a DHCP server and the clients are getting their IPs correctly and the Internet service is working on the server computer, the only problem i am having is that the client still can't surf which seems it's something about DNS, the following is the statics i have:

1- Incoming Internet Service (from the ISP):-
IP (DHCPed):
Subnetmask:
Gateway :
DNS1 :
DNS2 :
----------------------------------------------

2- Router (is used to avoide the mask problem from the ISP):-
IP (DHCPed) :
Scope(DHCP) : -
subnet mask :
----------------------------------------------

3- Windows Server:-
A- WAN (DHCPed)
B- LAN:-
IP :
Subnet:
Scope: -


PS: I've tried several DNS's, the origion DNS(, 208.67.220220), as well as , (the WAN DHCPed IP) but nothing happened.


any help will be very appreciated, Thanks in advance :)

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  • 14 Replies
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  • Latest Post Latest Post by Freaktech

Dani AI

Generated

Quick diagnosis built on the thread: because ’s server can browse while the clients cannot, the problem is most likely either DNS being handed out incorrectly or routing/NAT for the client subnet failing somewhere in the three-device chain that and flagged. Multiple DHCP servers and chained private subnets are the common root cause; fixing that cleanly will make DNS troubleshooting far simpler.

Essential, low-effort tests to isolate the fault (capture these outputs for analysis): 

ipconfig /all
ping 8.8.8.8
nslookup www.example.com
nslookup www.example.com 8.8.8.8

Interpretation and targeted fixes

  • If ping to a public IP works but name lookups fail: DNS only. Either run a DNS server on the Windows box and configure Forwarders (DNS MMC → server Properties → Forwarders) to public resolvers, or change the DHCP scope’s DNS setting so clients receive a reachable resolver. Also confirm the Windows DNS service is running and the server firewall allows DNS (UDP/TCP 53).
  • If ping to a public IP fails: routing/gateway problem. Verify the DHCP “Default Gateway” is the correct next-hop for that client subnet, and ensure the mid-router or server is performing NAT or has proper static routes to the ISP side. If the server is expected to NAT for client subnets, enable/configure RRAS NAT on the Windows box.

Operational checklist (parsimonious)

  • Ensure only one DHCP server operates per broadcast domain or separate scopes/VLANs; as suggested, give intermediate routers static LAN IPs and disable their DHCP where appropriate.
  • Verify DHCP scope options: Router (option 003) = correct gateway; Domain Name Servers (option 006) = chosen resolver (server or public).
  • Check for firewalls or packet filters on routers that might block DNS or block NAT for the client subnet.
  • Coordinate any changes to ISP-owned equipment with the ISP.

These steps isolate whether to fix DNS settings or routing/NAT. If the issue persists after these checks, collecting the exact ipconfig /all, route print, and an nslookup trace will show the remaining misconfiguration.

Recommended Answers

All 14 Replies

Member Avatar for sknake

Is the information listed under "1 - ISP" the information they sent you on paper to configure your device or is it the ISP's router and you have another router of your own behind theirs?

Member Avatar for JEESco

I get these information when I put their connection on another independent PC, and then i called them to make sure of it and was correct.
BTW they're using mikrotik as their own server

Member Avatar for sknake

So does the ISP have a router in your facility?

Member Avatar for JEESco

yup, as i think, they are routing using mikrotik but i can't reconfigure anything

Member Avatar for JEESco

Oh i forgot to mention that if i disattach the windows server pc, and connect clients directly to the router everything works like charm.

Member Avatar for Freaktech

You have two DHCP servers on your network. Your Windows 2003 server and your ISP's router. Can you log into the router? If so log in and turn DHCP off. If you can't contact your ISP and have them do it.

All 10.x.x.x addresses are private class A addresses not public internet addresses.

Member Avatar for JEESco

You have two DHCP servers on your network. Your Windows 2003 server and your ISP's router. Can you log into the router? If so log in and turn DHCP off. If you can't contact your ISP and have them do it.

All 10.x.x.x addresses are private class A addresses not public internet addresses.

Thanks Freaktech for replying but actually i have 3 DCP routers, the ISP router, the windoes server router and the router in between them cause of their subnet mask.

The problem is not with the 10.0.0.x class, because at my home i have connection from another ISP which its IPs are from this class ( the A class), and i didn't have problems with making a small network at my home.

But i am going to change it and see if it works

Member Avatar for Freaktech

Thanks Freaktech for replying but actually i have 3 DCP routers, the ISP router, the windoes server router and the router in between them cause of their subnet mask.

The problem is not with the 10.0.0.x class, because at my home i have connection from another ISP which its IPs are from this class ( the A class), and i didn't have problems with making a small network at my home.

But i am going to change it and see if it works

I wasn't saying there was a problem with it 10.x.x.x. if that's the class you want to use. But you are trying to use a Class A address that has a submask of with a Class C that has submask of 255.255.255.0. What is your third DHCP server handing out? What is your Gateway? Do you have routes from each scope on the routers to communicate? How many systems are on your network? Is it necessary to subnet?

Member Avatar for JEESco

now the mid router (which is in between my server and their server) is giving 172.20.0.x DHCP and subnet , and the windows DHCP server is 10.10.10.x subnet and i am still getting the same thing, just like before.

about your questions, there's only one PC which is the windows server PC behind the mid-router between the windows server and the ISP router, then the cliens those would connect to the windows server (the end users) may reach up to 200 - 250 client.

and i am using the third DHCP server (windows server) to control bandwith and also to have multi roles , 3 roles for each group.

Member Avatar for Freaktech

now the mid router (which is in between my server and their server) is giving 172.20.0.x DHCP and subnet , and the windows DHCP server is 10.10.10.x subnet and i am still getting the same thing, just like before.

about your questions, there's only one PC which is the windows server PC behind the mid-router between the windows server and the ISP router, then the cliens those would connect to the windows server (the end users) may reach up to 200 - 250 client.

and i am using the third DHCP server (windows server) to control bandwith and also to have multi roles , 3 roles for each group.

So all clients will be getting DHCP from the Windows Server?

Member Avatar for JEESco

So all clients will be getting DHCP from the Windows Server?

Yes, but according to their role, means some will have full access (guests) and others won't (some of employees)

Member Avatar for Freaktech

Yes, but according to their role, means some will have full access (guests) and others won't (some of employees)

Then you don't need the other two DHCP servers. Assign them static IP addresses for their LAN ports. Set your Gateway on the Server 2003 DHCP setting to the IP of the mid router. On the mid router set the Gateway address to the IP of the ISP router and you should be good to go.

Member Avatar for JEESco

Then you don't need the other two DHCP servers. Assign them static IP addresses for their LAN ports. Set your Gateway on the Server 2003 DHCP setting to the IP of the mid router. On the mid router set the Gateway address to the IP of the ISP router and you should be good to go.

How come!!, i agree with you that i don't need the DHCP mid-way router which is between the ISP's router and the windows server at my end, but i do need the windows server to be DHCP.

Member Avatar for Freaktech

How come!!, i agree with you that i don't need the DHCP mid-way router which is between the ISP's router and the windows server at my end, but i do need the windows server to be DHCP.

I am not saying to remove DHCP from the Windows Server. I am saying to turn off DHCP on the mid-way router and the ISP router. Then change the settings on your Windows server DHCP to hand out the correct gateway.

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