Change an Exchange internal IP address

Cableguy

Hi there,

I would like to change the internal addressing of my network which I can do no problem and have done but when I did this we no longer received external e-mail. We could connect to the exchange server and retrieve all our current e-mail but any new mail sent from outside to the exchange server after the IP address change was not delivered. I did also change the addressing on the firewall and router to reflect the changes so I do not know where I am going wrong.

Any ideas much appriciated.

Thanks for taking the time to read this.

liamo

Hi,

Have you tried telneting to port 25? To your exchange box from inside your network? To your external IP Address from outside your network? What happens?

Have you tried sending an email from outside? What happens? Do you get an error message? What is it?

Can you send internal mail?

Have you updated your DNS records to reflect the IP address changes you've made?

Regards,

Liam

crowej

when you say you changed the addresses on your firewall do you mean the firewall its self's address, you may have to change the policies on the firewall to direct/allow mail traffic to the new internal address of your exchange server

ntlbell

Are you using a smart host or do mails go directly to exchange?

Cableguy

Hi Guys,

Right I`ve now changed the ip address of the exchange Server again. From 10.0.0.1 to 10.0.1.3. This is also a DHCP server and has now stopped issuing IP adresses. When I manually change IP addresses on workstations to match the network I can send internal e-mail fine and external e-mail gets delivered to.

The problem is now any external e-mail is not being delivered. When I try telneting from outside to port 25 I get no response from the server and when I check the logs on the firewall its telling me traffic on port 25 is being forwarded to the new server IP address.

I am not sure how to update my internal DNS records Liamo so any help there would be great.

Cheers guys

liamo

This is also a DHCP server and has now stopped issuing IP adresses.

Is the DHCP server running? Check this in Administrative Tools/DHCP. If you've made changes to it you may need to "Authorize" it.

The problem is now any external e-mail is not being delivered. When I try telneting from outside to port 25 I get no response from the server and when I check the logs on the firewall its telling me traffic on port 25 is being forwarded to the new server IP address.

But can you telnet to the server from the internal network? If you can reach port 25 from the internal network but not from outside then your problem is related to the forwarding of port 25 to the server.
If you can't reach port 25 from the internal network then the problem is at the server.

I am not sure how to update my internal DNS records Liamo so any help there would be great.

In Administrative Tools/DNS, under the domain node (whatever your domain name is), you need to modify the host record for your server to reflect the new IP Address.

Additionally, have you looked in Event Viewer to see what errors, if any, are being reported?

Regards,

Liam

PS. I've made an assumption that this is a Small Business Server. Just to clarify things, please specify what the OS is.

Cableguy

Hi Liam,

liamo wrote:

Is the DHCP server running? Check this in Administrative Tools/DHCP. If you've made changes to it you may need to "Authorize" it.

Did this and have it running again.

[/QUOTE]But can you telnet to the server from the internal network[/QUOTE]

I can telnet the domain name on port 25 internally and I get a 220 response from the server but if I telnet the internal IP address of the server I do not get a response from the server. When I telnet the external IP address or domain name of the server from an external source on port 25 I get no response from either even though the firewall router is telling me its forwarding the request to the correct IP address of the server.

[/QUOTE]In Administrative Tools/DNS, under the domain node (whatever your domain name is), you need to modify the host record for your server to reflect the new IP Address.[/QUOTE]

Have looked here but can`t see anything to do with host record.

[/QUOTE]Additionally, have you looked in Event Viewer to see what errors, if any, are being reported?[/QUOTE]

Doesn`t tell me anything in the event viewer.

[/QUOTE]PS. I've made an assumption that this is a Small Business Server. Just to clarify things, please specify what the OS is.[/QUOTE]

Its a Windows 2000 server (Standard) with Exchange 2000 installed.

Thanks for the help so far.

liamo

Did this and have it running again.

Excellent!

I can telnet the domain name on port 25 internally and I get a 220 response from the server but if I telnet the internal IP address of the server I do not get a response from the server.

There's something screwy there.
You're getting a response from some mail server on port 25.
What address does the server name resolve to when you do nslookup <domain name>?

Do you have a domain, eg CompanyName.com that is hosted externally and this is what you're telnetting to? In this case, the external hosting company is responding to your telnet request and your internal server is, in fact, not responding. Just a guess.

When I telnet the external IP address or domain name of the server from an external source on port 25 I get no response from either even though the firewall router is telling me its forwarding the request to the correct IP address of the server.

Assuming that you're forwarding traffic to the correct IP Address, the server is not responding on port 25. Have you restarted Exchange or rebooted the server? I'm not recommending this, just asking.

Have looked here but can`t see anything to do with host record.

When you select your domain in the left pane, you should see a number of host records in the right pane. Locate your server entry and modify its IP Address.


Ok. Let's look at this logically.
If you are telnetting to the correct IP Address and the correct port and there is no response then, unless there are some other factors that have not been disclosed, there is no service running on port 25. You need to find out why.
If you are telnetting to a name on port 25 and you're getting a response then the name is resolving to an unexpected IP Address. You need to find out what IP Address and why.

Regards,

Liam

PS My Windows Admin experience (particularly Exchange) is limited and I'm running out of ideas. I may not be able to help much more.

Cableguy

Hi Liamo and all,

I eventually resolved this problem and would like to thanks yous for your help.

The resolution was to change the IP address in the Exchange System Manager under the desired protocol. So if you right clicked on the SMTP and selected properties inter the general tab is the default IP address for the virtual server. This was still the old IP address and when I changed it to the new IP address of the server everything worked swell.

Thanks again guys for the help.

Bernard.

liamo

Excellent. That's one for me to remember.

Liam