Network access to Internet - Hlep

I provide free support to small office network used by a local charity. The
network consists of:

- A network server running NT4/SP6. Mdeamon runs on the server to provide
email distribution/collection to/from 4 client machines. The server also
runs VSocks Light to provide dial-up(0845) access via Clarinet for POP3/SMTP
mail and internet access. MD dials up the Clarinet POP account every hour
to download incoming mail and send the outgoing mail via STMP.

- Four client machines running W98. Email is handled via Mdeamon running on
the network server. Internet access is provided by Vsocks light proxy
server running on the network server.

All was working fine until some 7 days ago when the charity contacted me to
report that Internet access was failing from the client desktop machines. I
have now determined that the mail collection and deliver works OK but client
internet access is indeed failing. Looks like no DNS resolution? However
if I access the internet from the server via Vsocks then all seems to be OK.
The people in the office cannot think of any action that was taking place
prior to the internet access failure. When IE starts on a client machine it
will trigger Vsocks to dial out from the server and connect to Clarinet OK.
However IE then times out "page cannot be displayed". I did suspect MSblast
on the NT server but cannot find any trace.

Frankly I am now lost. I would appreciate any help or advice. TIA

Regards

Chris


---
Outgoing mail is certified Virus Free. Verified Antec Server 6/2003
Checked by AVG anti-virus system (http://www.grisoft.com).
Version: 6.0.511 / Virus Database: 308 - Release Date: 18/08/2003

On Tue, 19 Aug 2003 14:43:03 +0100, "chris" <(E-Mail Removed)> wrote:

<snip>
>All was working fine until some 7 days ago when the charity contacted me to
>report that Internet access was failing from the client desktop machines. I
>have now determined that the mail collection and deliver works OK but client
>internet access is indeed failing. Looks like no DNS resolution?

Tried pinging from one of the client machines? Ping an known good ip
address and you should then be able to determine whether it's DNS
related or not.

Is DNS handled by your NT server? or are client's contacting clara's
DNS directly?


Regards

Jeff

On Tue, 19 Aug 2003 17:39:39 +0100, "chris" <(E-Mail Removed)> wrote:

>Thanks for help Jeff
>
>
>> Tried pinging from one of the client machines? Ping an known good ip
>> address and you should then be able to determine whether it's DNS
>> related or not.
>
>Can ping client machine to server OK. Server is 192.168.0.1. This can be
>pinged from clients. But cannot ping from client to enternal IP address.

Have you checked the default route on the clients is set correctly?

If the clients are getting their addresses from the server via DHCP,
you may find that the server is no longer supplying this setting to
the clients.

Derek
--
The Internet is totally out of control, impossible to map accurately, and
being used far beyond its original intentions. So far, so good.
-- Dr. Dobb's Journal May 1993

Derek wrote:

> On Tue, 19 Aug 2003 17:39:39 +0100, "chris" <(E-Mail Removed)> wrote:
>
>>Thanks for help Jeff
>>
>>
>>> Tried pinging from one of the client machines? Ping an known good ip
>>> address and you should then be able to determine whether it's DNS
>>> related or not.
>>
>>Can ping client machine to server OK. Server is 192.168.0.1. This can be
>>pinged from clients. But cannot ping from client to enternal IP address.
>
> Have you checked the default route on the clients is set correctly?
>
> If the clients are getting their addresses from the server via DHCP,
> you may find that the server is no longer supplying this setting to
> the clients.
>
> Derek

thats unlikely as he said mail is working fine, and he is using a socks
proxy so default route/gateway or whatever you wanna call it doesnt apply,

its probably a dns propogation problem with whatever relays dns on the
server, have a look at it, failing that, you could setup wingate or ICS or
something on the server to give the machines full access to the internet
(i.e. not through proxy) and set the dns on those machines to the dns
servers that you use.

> >Can ping client machine to server OK. Server is 192.168.0.1. This can
be
> >pinged from clients. But cannot ping from client to enternal IP address.
>
> Have you checked the default route on the clients is set correctly?

I'm not really sure what is meant here Derek? See below.

>
> If the clients are getting their addresses from the server via DHCP,
> you may find that the server is no longer supplying this setting to
> the clients.

Clients IP addresses are fixed IP addresses in the series 192.168.0.1x

C.







---
Outgoing mail is certified Virus Free. Verified Antec Server 6/2003
Checked by AVG anti-virus system (http://www.grisoft.com).
Version: 6.0.512 / Virus Database: 309 - Release Date: 19/08/2003

> its probably a dns propogation problem with whatever relays dns on the
> server, have a look at it, failing that, you could setup wingate or ICS or
> something on the server to give the machines full access to the internet
> (i.e. not through proxy) and set the dns on those machines to the dns
> servers that you use.
>

This looks like a good line of investigation for me, Mike. I can access
the internet from the NT4 server via the server proxy (Vsocks running on the
NT4 server) but not from the clients; although the clients will trigger the
proxy to initiate dial-up to the ISP. So this does seem to confirm that the
problem is dns related but I'm stuck as to how to pin this down further.

C.


---
Outgoing mail is certified Virus Free. Verified Antec Server 6/2003
Checked by AVG anti-virus system (http://www.grisoft.com).
Version: 6.0.512 / Virus Database: 309 - Release Date: 19/08/2003

On Tue, 19 Aug 2003 22:13:44 +0100, "chris" <(E-Mail Removed)> wrote:

>
>> its probably a dns propogation problem with whatever relays dns on the
>> server, have a look at it, failing that, you could setup wingate or ICS or
>> something on the server to give the machines full access to the internet
>> (i.e. not through proxy) and set the dns on those machines to the dns
>> servers that you use.
>>
>This looks like a good line of investigation for me, Mike. I can access
>the internet from the NT4 server via the server proxy (Vsocks running on the
>NT4 server) but not from the clients; although the clients will trigger the
>proxy to initiate dial-up to the ISP. So this does seem to confirm that the
>problem is dns related but I'm stuck as to how to pin this down further.

Just throwing this in here - Vsocks only appears to allow you to enter
one external DNS server: Are you sure that the server Vsocks is using
actually works?

(I'd note that one of the DNS servers you mentioned (213.120.62.100)
doesn't look very healthy from here.)

Are you familar with nslookup?

Derek
--
If I took some seriously hard drugs and invented the most implausible
discworld physics I could think of I'd still be outdone by a couple
of sober physicists and mathematicians. -Terry Pratchett

> Just throwing this in here - Vsocks only appears to allow you to enter
> one external DNS server: Are you sure that the server Vsocks is using
> actually works?
>
> (I'd note that one of the DNS servers you mentioned (213.120.62.100)
> doesn't look very healthy from here.)
>
> Are you familar with nslookup?

No, but I'm sure going to find out since you think that it might help me :-)

>
> Derek
> --
> If I took some seriously hard drugs and invented the most implausible
> discworld physics I could think of I'd still be outdone by a couple
> of sober physicists and mathematicians. -Terry
Pratchett


---
Outgoing mail is certified Virus Free. Verified Antec Server 6/2003
Checked by AVG anti-virus system (http://www.grisoft.com).
Version: 6.0.512 / Virus Database: 309 - Release Date: 19/08/2003