Simple LAN problem

  • Thread starter Thread starter Picard
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Picard

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... which I don't understand.

Long story short. My school is going to start using an admin program supplied by the Education department and has provided a number of PCs preinstalled and preconfigured to work within the IP range of 172.16.0.xxx. The rest of our PCs, that used the same IP adresses as the ADSL router, was also changed to use the new required IP range.

We have a ADSL router with an IP adress of 192.168.1.xxx

That is connected to a PC (which acts as the server for the new admin program) with 2 network cards (1 onboard, 1 in PCI slot). The cable from the ADSL router goes into the PCI card and obtains its IP adress automatically. The onboard netw. card is configured with an IP address of 172.16.0.1, subnet mask 255.255.0.0 and the preferred DNS server of the ADSL router (192.168.1.xxx)

From the onboard card the cabling goes to some PCs and some switches.

The workstations are configured with the adresses of 172.16.0.xxx, Subnet mask 255.255.0.0, empty default gateway, preferred DNS server of 172.16.0.1.

The workstations' LAN settings in the Internet browser are also set to use a proxy server of 172.16.0.1 and port 8090.

Internet browsing works fine on all workstations but on one workstation we have Outlook and it cannot connect to any pop3 or smtp server anymore after this reconfiguration.

I also cannot ping any website.

I cannot go back to our old IP addresses because then the Admin program will not work. Also the Education department want to use Teamviewer to gain access to our network with their prescribed setup.

Can anyone offer any advice on how to fix the one workstation's e-mail?

Thanks.
 
Last edited by a moderator:
sounds like you need to have dns for it to resolve addresses. you can try no-ip (google it), or there a few others free services you can try.
 
Your problem here is that there is no default route out of the network. When the ADSL router handled the addresses, the DHCP handed out the router's IP as the default route to the PCs.

The PCs can see the internet because there is a proxy server running on the server machine and that has been configured in the browsers, but raw IP cannot get out.

Quickest solution would be to plug a second network card into the PC requiring Outlook and connect it to the ADSL router with the second card. The first network connection to the department's PC must remain. Then Outlook can get out.

The other option would be to configure the ADSL to live on the 172.16.x.x space instead of the 192.168.1.x space, but how that will affect the department's server, I cannot say.
 
bruce_the_loon said:
Quickest solution would be to plug a second network card into the PC requiring Outlook and connect it to the ADSL router with the second card. The first network connection to the department's PC must remain. Then Outlook can get out.
Click to expand...

Our ADSL router only has one network port. :(

The other option would be to configure the ADSL to live on the 172.16.x.x space instead of the 192.168.1.x space, but how that will affect the department's server, I cannot say.
Click to expand...

Can an ADSL router's IP address be changed? I haven't explored this possibility yet. I can only work on the network tomorrow.

Thanks for your help.
 
bruce_the_loon said:
Your problem here is that there is no default route out of the network. When the ADSL router handled the addresses, the DHCP handed out the router's IP as the default route to the PCs.

The PCs can see the internet because there is a proxy server running on the server machine and that has been configured in the browsers, but raw IP cannot get out.

Quickest solution would be to plug a second network card into the PC requiring Outlook and connect it to the ADSL router with the second card. The first network connection to the department's PC must remain. Then Outlook can get out.

The other option would be to configure the ADSL to live on the 172.16.x.x space instead of the 192.168.1.x space, but how that will affect the department's server, I cannot say.
Click to expand...

Alternatively, enable IP forwarding on the server PC, and set it as the default gateway for all the others ;)
 
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