DNS and DHCP

G

Guest

Hi, I'm a little confused between DHCP and DNS. I have a second computer in
my network that can't connect to the Internet. The ISP has a diagnostics
feature which checks the settings of the connection in a computer, and the
only problem found was that the DNS server can't be pinged. My DHCP server is
okay. Is the DNS server and the DHCP server the same? (DSL router)
The computer is Win XP Home SP2.
Thanks.
 
C

Chuck

Hi, I'm a little confused between DHCP and DNS. I have a second computer in
my network that can't connect to the Internet. The ISP has a diagnostics
feature which checks the settings of the connection in a computer, and the
only problem found was that the DNS server can't be pinged. My DHCP server is
okay. Is the DNS server and the DHCP server the same? (DSL router)
The computer is Win XP Home SP2.
Thanks.
Click to expand...

Brian,

You might have DHCP and DNS provided by the same Windows server, but each
function is separate.

DHCP issues IP settings for a computer requesting an IP address. DHCP may or
may not provide DNS server information, to any computer requesting an address.

DNS resolves (looks up) computer name to address, or address to name. A DNS
server will provide the lookup for a computer that registered with it, which may
or may not be a computer that used a DHCP server.

Most NAT routers provide DHCP services, as they are the hub of a private address
LAN. Some NAT routers may provide DNS services, or they may simply relay a DNS
request to whatever DNS servers are configured for them. Most NAT routers will
not provide DNS registration / lookup for your computers. If you're using a NAT
router for DHCP, most likely your DNS server will be one provided by your ISP.

How are your computers connected to each other, and to the Internet? Make and
model of any network equipment would be useful here.
 
G

Guest

Hi Chuck,

The computers both connect to the router through ethernet cables. I ran the
Network Setup Wizard to connect the two to each other after installing the
router. The router is a VersaLink Gateway model 327W by Westell.
 
C

Chuck

Hi Chuck,

The computers both connect to the router through ethernet cables. I ran the
Network Setup Wizard to connect the two to each other after installing the
router. The router is a VersaLink Gateway model 327W by Westell.
Click to expand...

Hi Brian,

Well, looking at the specs sheet for the 327W, it says the Routing component
includes "NAT, DHCP, DNS". I would guess that means that it gets DNS from your
ISP (or whoever), and relays same to your computers when requested. I don't
think it includes a DNS server for name resolution on your LAN. In your case,
you should be getting DNS from your ISP, and resolving names on your LAN through
NetBIOS broadcast.
<http://nitecruzr.blogspot.com/2005/05/address-resolution-on-lan.html>

Please provide "ipconfig /all" from both computers, as a start. Read this
article, and linked articles, and follow instructions precisely:
<http://nitecruzr.blogspot.com/2005/05/troubleshooting-network-neighborhood.html#AskingForHelp>
 
G

Guest

All right, here's the ipconfig/all (and the browstat, if it will help) for
the main computer:

Windows IP Configuration
Host Name . . . . . . . . . . . . : RENIERLUBOA
Primary Dns Suffix . . . . . . . :
Node Type . . . . . . . . . . . . : Unknown
IP Routing Enabled. . . . . . . . : No
WINS Proxy Enabled. . . . . . . . : No

Ethernet adapter Local Area Connection:

Connection-specific DNS Suffix . : myhome.westell.com
Description . . . . . . . . . . . : Linksys LNE100TX(v5) Fast
Ethernet Adapter
Physical Address. . . . . . . . . : 00-12-17-50-F0-DC
Dhcp Enabled. . . . . . . . . . . : Yes
Autoconfiguration Enabled . . . . : Yes
IP Address. . . . . . . . . . . . : 192.168.1.47
Subnet Mask . . . . . . . . . . . : 255.255.255.0
Default Gateway . . . . . . . . . : 192.168.1.1
DHCP Server . . . . . . . . . . . : 192.168.1.1
DNS Servers . . . . . . . . . . . : 192.168.1.1
192.168.1.1
Lease Obtained. . . . . . . . . . : Sunday, August 28, 2005 2:30:57 PM
Lease Expires . . . . . . . . . . : Monday, August 29, 2005 2:30:57 PM
---
Status for domain MSHOME on transport
\Device\NetBT_Tcpip_{FC1D8958-C582-43E9-900C-550140E86555}
Browsing is active on domain.
Master browser name is: MICHAELLUBOA
Could not connect to registry, error = 5 Unable to determine build of
browser master: 5
Unable to determine server information for browser master: 5
1 backup servers retrieved from master MICHAELLUBOA
\\MICHAELLUBOA
There are 2 servers in domain MSHOME on transport
\Device\NetBT_Tcpip_{FC1D8958-C582-43E9-900C-550140E86555}
There are 1 domains in domain MSHOME on transport
\Device\NetBT_Tcpip_{FC1D8958-C582-43E9-900C-550140E86555}

This is for the second computer:

Windows IP Configuration

Host Name . . . . . . . . . . . . : MichaelLuboa
Primary Dns Suffix . . . . . . . :
Node Type . . . . . . . . . . . . : Unknown
IP Routing Enabled. . . . . . . . : No
WINS Proxy Enabled. . . . . . . . : No
DNS Suffix Search List. . . . . . : myhome.westell.com

Ethernet adapter Local Area Connection:

Connection-specific DNS Suffix . : myhome.westell.com
Description . . . . . . . . . . . : Intel(R) PRO/100 VE Network
Connection
Physical Address. . . . . . . . . : 00-00-39-87-4C-DB
Dhcp Enabled. . . . . . . . . . . : Yes
Autoconfiguration Enabled . . . . : Yes
IP Address. . . . . . . . . . . . : 192.168.1.46
Subnet Mask . . . . . . . . . . . : 255.255.255.0
Default Gateway . . . . . . . . . : 192.168.1.1
DHCP Server . . . . . . . . . . . : 192.168.1.1
DNS Servers . . . . . . . . . . . : 192.168.1.1
192.168.1.1
Lease Obtained. . . . . . . . . . : Sunday, August 28, 2005 2:29:19 PM
Lease Expires . . . . . . . . . . : Monday, August 29, 2005 2:29:19 PM
---
Status for domain MSHOME on transport
\Device\NetBT_Tcpip_{56A0032E-E7D1-4AE6-88C6-0E10A312A767}
Browsing is active on domain.
Master browser name is: MICHAELLUBOA
Master browser is running build 2600
1 backup servers retrieved from master MICHAELLUBOA
\\MICHAELLUBOA
There are 2 servers in domain MSHOME on transport
\Device\NetBT_Tcpip_{56A0032E-E7D1-4AE6-88C6-0E10A312A767}
There are 1 domains in domain MSHOME on transport
\Device\NetBT_Tcpip_{56A0032E-E7D1-4AE6-88C6-0E10A312A767}

I might be misinterpreting it, but it's odd that MichaelLuboa (the one
without Internet access/second computer) is the master browser and not
RenierLuboa.
Thanks for the help!
 
G

Guest

Two things come to mind:

One: You have 2 DNS IPs that are the same.

Two: Is your router pulling the ISP information automatically or did you
enter them manually? If the latter check the DNS information on the router
for your WAN port.
 
C

Chuck

All right, here's the ipconfig/all (and the browstat, if it will help) for
the main computer:

Windows IP Configuration
Host Name . . . . . . . . . . . . : RENIERLUBOA
Primary Dns Suffix . . . . . . . :
Node Type . . . . . . . . . . . . : Unknown
IP Routing Enabled. . . . . . . . : No
WINS Proxy Enabled. . . . . . . . : No

Ethernet adapter Local Area Connection:

Connection-specific DNS Suffix . : myhome.westell.com
Description . . . . . . . . . . . : Linksys LNE100TX(v5) Fast
Ethernet Adapter
Physical Address. . . . . . . . . : 00-12-17-50-F0-DC
Dhcp Enabled. . . . . . . . . . . : Yes
Autoconfiguration Enabled . . . . : Yes
IP Address. . . . . . . . . . . . : 192.168.1.47
Subnet Mask . . . . . . . . . . . : 255.255.255.0
Default Gateway . . . . . . . . . : 192.168.1.1
DHCP Server . . . . . . . . . . . : 192.168.1.1
DNS Servers . . . . . . . . . . . : 192.168.1.1
192.168.1.1
Lease Obtained. . . . . . . . . . : Sunday, August 28, 2005 2:30:57 PM
Lease Expires . . . . . . . . . . : Monday, August 29, 2005 2:30:57 PM
---
Status for domain MSHOME on transport
\Device\NetBT_Tcpip_{FC1D8958-C582-43E9-900C-550140E86555}
Browsing is active on domain.
Master browser name is: MICHAELLUBOA
Could not connect to registry, error = 5 Unable to determine build of
browser master: 5
Unable to determine server information for browser master: 5
1 backup servers retrieved from master MICHAELLUBOA
\\MICHAELLUBOA
There are 2 servers in domain MSHOME on transport
\Device\NetBT_Tcpip_{FC1D8958-C582-43E9-900C-550140E86555}
There are 1 domains in domain MSHOME on transport
\Device\NetBT_Tcpip_{FC1D8958-C582-43E9-900C-550140E86555}

This is for the second computer:

Windows IP Configuration

Host Name . . . . . . . . . . . . : MichaelLuboa
Primary Dns Suffix . . . . . . . :
Node Type . . . . . . . . . . . . : Unknown
IP Routing Enabled. . . . . . . . : No
WINS Proxy Enabled. . . . . . . . : No
DNS Suffix Search List. . . . . . : myhome.westell.com

Ethernet adapter Local Area Connection:

Connection-specific DNS Suffix . : myhome.westell.com
Description . . . . . . . . . . . : Intel(R) PRO/100 VE Network
Connection
Physical Address. . . . . . . . . : 00-00-39-87-4C-DB
Dhcp Enabled. . . . . . . . . . . : Yes
Autoconfiguration Enabled . . . . : Yes
IP Address. . . . . . . . . . . . : 192.168.1.46
Subnet Mask . . . . . . . . . . . : 255.255.255.0
Default Gateway . . . . . . . . . : 192.168.1.1
DHCP Server . . . . . . . . . . . : 192.168.1.1
DNS Servers . . . . . . . . . . . : 192.168.1.1
192.168.1.1
Lease Obtained. . . . . . . . . . : Sunday, August 28, 2005 2:29:19 PM
Lease Expires . . . . . . . . . . : Monday, August 29, 2005 2:29:19 PM
---
Status for domain MSHOME on transport
\Device\NetBT_Tcpip_{56A0032E-E7D1-4AE6-88C6-0E10A312A767}
Browsing is active on domain.
Master browser name is: MICHAELLUBOA
Master browser is running build 2600
1 backup servers retrieved from master MICHAELLUBOA
\\MICHAELLUBOA
There are 2 servers in domain MSHOME on transport
\Device\NetBT_Tcpip_{56A0032E-E7D1-4AE6-88C6-0E10A312A767}
There are 1 domains in domain MSHOME on transport
\Device\NetBT_Tcpip_{56A0032E-E7D1-4AE6-88C6-0E10A312A767}

I might be misinterpreting it, but it's odd that MichaelLuboa (the one
without Internet access/second computer) is the master browser and not
RenierLuboa.
Thanks for the help!
Click to expand...

Brian,

The choice of master browser is a fascinating one, if you're into that sort of
thing. You can read my narrative, if you wish:
<http://nitecruzr.blogspot.com/2005/04/nt-browser-or-why-cant-i-always-see.html>

The master browser, when elected, and given equal browser servers, is generally
the one that's been powered on the longest. If you wish to make RENIERLUBOA the
master browser, you can disable the browser service on MichaelLuboa.

Your browser situation, as it is, looks good - both computers recognise the same
master browser (MICHAELLUBOA), and both see 2 servers (presumably each other).
Both computers are running only NBT as a transport. Both computers are getting
DHCP from 192.168.1.1, which appears to point to itself as the immediate DNS
server.

What make and model NAT router do you have? I would think that you would
configure the addresses of the ISP DNS servers into the router settings, so that
could be issued to MICHAELLUBOA and RENIERLUBOA. I don't think it's a good idea
that both computers should point to 192.168.1.1 twice. Are both computers
configured to "Obtain DNS server addresses automatically", or is 192.168.1.1
manually entered into both fields on each computer? Somewhere you have to point
to your ISPs DNS server, as no NAT routers that I know of have fully functional
DNS servers.

Wherever you designate a DNS server, you have either 2 or 3 DNS server address
fields, in order that you may designate a primary and one or two backup DNS
server addresses. You are not obligated to identify any more than a primary
server however. And specifying the same server as primary and backup makes no
sense. If the server is dead, it's dead. You need a backup (and a second
backup, if your router setup will allow that).
 
G

Guest

Chuck said:
Your browser situation, as it is, looks good - both computers recognise the same
master browser (MICHAELLUBOA), and both see 2 servers (presumably each other).
Both computers are running only NBT as a transport. Both computers are getting
DHCP from 192.168.1.1, which appears to point to itself as the immediate DNS
server.

What make and model NAT router do you have? I would think that you would
configure the addresses of the ISP DNS servers into the router settings, so that
could be issued to MICHAELLUBOA and RENIERLUBOA. I don't think it's a good idea
that both computers should point to 192.168.1.1 twice. Are both computers
configured to "Obtain DNS server addresses automatically", or is 192.168.1.1
manually entered into both fields on each computer? Somewhere you have to point
to your ISPs DNS server, as no NAT routers that I know of have fully functional
DNS servers.
Click to expand...

Chuck,

The Westell router is the only (NAT) router I have. Both of the computers
are configured to obtain the DNS server address automatically (I believe this
answers for Tidus4Yuna as well). So should I manually assign a DNS server
address for one of the computers (or both, to differ it from the DHCP
address)? If so, I'm not sure what addresses I can put in.
(I apologize if this is taking a while to solve...)
 
C

Chuck

Chuck,

The Westell router is the only (NAT) router I have. Both of the computers
are configured to obtain the DNS server address automatically (I believe this
answers for Tidus4Yuna as well). So should I manually assign a DNS server
address for one of the computers (or both, to differ it from the DHCP
address)? If so, I'm not sure what addresses I can put in.
(I apologize if this is taking a while to solve...)
Click to expand...

Brian,

This thread is not near as long as many I've been in, don't worry about that.

Check the router, and see what DNS settings it has. I'm not sure why you should
be picking up (for both MichaelLuboa and RENIERLUBOA):
DNS Servers . . . . . . . . . . . : 192.168.1.1
192.168.1.1
Somewhere you have to have the actual DNS servers that your ISP provides. The
server at 192.168.1.1 isn't gonna have any information - it has to get DNS data
from somewhere.

Where does Tidus4Yuna come into the picture? What DNS servers does it use?
 
G

Guest

Chuck,

I think I will contact my ISP for the DNS server addresses for that. How do
I check the DNS server settings for my router (and change it, should I have
the proper DNS server address from my ISP)? There was no "installation" for
it, so I'm not sure where to go.

Tidus4Yuna also asked if my settings are set to obtain DNS address
automatically, I didn't want to ignore his/her post.

Thanks.
 
C

Chuck

Chuck,

I think I will contact my ISP for the DNS server addresses for that. How do
I check the DNS server settings for my router (and change it, should I have
the proper DNS server address from my ISP)? There was no "installation" for
it, so I'm not sure where to go.

Tidus4Yuna also asked if my settings are set to obtain DNS address
automatically, I didn't want to ignore his/her post.

Thanks.
Click to expand...

Brian,

Can you access the router configuration wizard (from your browser)?

From looking at the 327W User Guide, it looks like you should have a WAN
Configuration menu. You'll have a pair of settings - "DNS Primary" and "DNS
secondary", and that's where you want to put the addresses that your ISP
provides you.

OK, I see now "Tidus4Yuna" was a person. I was thinking you were sneaking a
third computer name into the discussion.
 
G

Guest

Chuck,

Okay, I talked to my ISP and this time the person detected the problem. It
went down to him giving me a primary and secondary DNS address, but still I
couldn't ping or access a website. He said that something's blocking my DNS
from working, and I need to contact my manufacturer for it. The problem is my
with computer...
The Windows firewall from Network Connections is switched off, my McAfee
firewall is on standard settings.
 
C

Chuck

Chuck,

Okay, I talked to my ISP and this time the person detected the problem. It
went down to him giving me a primary and secondary DNS address, but still I
couldn't ping or access a website. He said that something's blocking my DNS
from working, and I need to contact my manufacturer for it. The problem is my
with computer...
The Windows firewall from Network Connections is switched off, my McAfee
firewall is on standard settings.
Click to expand...

Brian,

See if you need to set MPF to Trust your DNS servers.
 
G

Guest

Chuck,

What is MPF, and how do I check this setting? Microsoft doesn't seem to
explain it in their knowledge database.
Thanks a lot.
 
C

Chuck

Chuck,

What is MPF, and how do I check this setting? Microsoft doesn't seem to
explain it in their knowledge database.
Thanks a lot.
Click to expand...

Brian,

McAfee Personal Firewall. There have been several recent issues involving DNS
problems where the personal firewalls, for some reason, have to trust the DNS
servers.
 
G

Guest

Chuck,

I checked my McAfee Firewall and made sure that it trusts my DNS addresses,
but that didn't solve it. One thing, though, when I brought my computer out
of standby, I received the "Limited or no connection" message. I tried to use
Repair but the IP Address couldn't be renewed. So I also tried
ipconfig/renew, but it couldn't contact the DHCP server... Could this be
another effect of the same problem? (At the time I first posted this problem
ipconfig/renew is successful, until today.)
I talked to my computer manufacturer and they said that I should reinstall
my network driver with its cd. I'm not sure if I have it, but I did see a
driver download (Intel PRO/100 VE Network Connection) in the Microsoft
website. Would that work just as well? The system doesn't detect any problem
with it so far.
 
C

Chuck

Chuck,

I checked my McAfee Firewall and made sure that it trusts my DNS addresses,
but that didn't solve it. One thing, though, when I brought my computer out
of standby, I received the "Limited or no connection" message. I tried to use
Repair but the IP Address couldn't be renewed. So I also tried
ipconfig/renew, but it couldn't contact the DHCP server... Could this be
another effect of the same problem? (At the time I first posted this problem
ipconfig/renew is successful, until today.)
I talked to my computer manufacturer and they said that I should reinstall
my network driver with its cd. I'm not sure if I have it, but I did see a
driver download (Intel PRO/100 VE Network Connection) in the Microsoft
website. Would that work just as well? The system doesn't detect any problem
with it so far.
Click to expand...

Brian,

Before I continue, and whatever you do, do not download driver updates from
Microsoft. Download Windows components from Microsoft, but download non-Windows
components (third party drivers) only from the vendor. This subject comes up
every week.
 
C

Chuck

Chuck,

All right, thanks for the heads up.
Click to expand...

OK, Brian,

Based upon what you've done to date, and the current symptom, I think re
installing the network card makes the most sense, as the next step. Just forget
about the drivers which you may or may not be able to find in your library; get
the most recent version available from the vendor, online.

For cleanest results:
1) Un install drivers from Device Manager.
2) Reboot.
3) Let the operating system rediscover the network card. Give it the new
drivers.
4) Reboot.
<http://nitecruzr.blogspot.com/2005/08/re-install-your-network-hardware.html>
 
G

Guest

Chuck,

I lose the connection after restarting a second time. When I restarted the
first time, after it detected the ethernet controller and the Intel PRO/100,
I could connect again. Then I installed the network driver from the CD (there
was no update for it online) and rebooted... but I went back to the same
problem.
I have a feeling I'm misunderstanding something. The "Intel PRO/100 VE
Network Connection" is the driver, right? The one to uninstall from Device
Manager and reinstall from the CD...or is the driver another thing?
 

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