MC75: How to disable DHCP over serial connection?

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C Charles Malm 3 years 5 months ago
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I have a customer that is using a PPP server connected to a MC75 over serial, the server assigns an IP address to the MC75 prior to the DHCP request being received and thus ignores it. The MC75 does not like this and terminates the connection. Is there a way to disable DHCP over a serial connection?

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6 Replies

D David Meyer

I don't know if the PPTP menu item is their PPP connection, but it may be.  Have them try that.

C Charles Malm

I’ve tried several configurations of static IP addresses but I’m not getting anywhere.  Actually, the connection progress isn’t getting as far.  Here is what I’m seeing:

09/10 13:58:37 WM_RASDIALEVENT - rasconnstate is RASCS_OpenPort, dwRasError =

09/10 13:58:37 WM_RASDIALEVENT - rasconnstate is RASCS_PortOpened, dwRasError =

09/10 13:58:37 WM_RASDIALEVENT - rasconnstate is RASCS_Disconnected, dwRasError =

 

When I specify the IP address in the “PPTP NDISWAN Miniport”, should I be using the same IP address that I specified in the “PPP RAS entry?  I’ve tried it several different ways but I get the same result.

 

1.       If I make a change to the “PPTP NDISWAN Miniport”, do those changes take effect immediately or do I need to reboot the device?

2.       I have the MC75 configured to access my WLAN from its WiFi configuration.  I do this so that I connect to the device and deploy my applications from visual Studio 2008.  This is a different network than the PPP network I’m trying to open a connection with.  Will having this enabled affect the results of the PPP connection?  It didn’t seem to have any effect prior to changing the “PPTP NDISWAN Miniport”, so I don’t think it will, but I thought I’d mention it.

D David Meyer

The WiFi stuff shouldn't matter.  As for setting the static IP address, that was just to prevent DHCP from happening (since the customer thought DHCP was the cause for the disconnection).  I still don't know why the customer thinks that the issue was due to DHCP. I am not familiar enough with creating PPP connections to know why the connection is getting dropped.

C Charles Malm

Thanks Dave, I will let them know/ask.

C Charles Malm

Dave,

Here is the response from the customer:

Thanks for the information.  In the snippet below, you said to “select the PPP connection”.  When I go to Settings -> Connections -> WiFi, I see the choice for “PPTP NDISWAN Miniport”.  Is this what you mean by the “PPP connection”?
 
To answer your question about setting an IP address on the PPP connection, when I created the “PPP” RAS entry, I used the following options:
RASEO_ProhibitEAP |
RASEO_ProhibitMsCHAP2 |
RASEO_ProhibitMsCHAP |
RASEO_ProhibitCHAP |
RASEO_ProhibitPAP |
RASEO_SwCompression |
RASEO_IpHeaderCompression |
RASEO_SpecificIpAddr
 
By specifying RASEO_SpecificIpAddr I can then fill in the static IP address in the field ipaddr.  The structure for the RAS entry I’m referring to is called RASENTRY.

D David Meyer

If the PPP connection shows up in Microsoft's GUI for their network cards (called WiFi under settings > connections), you can select the PPP connection and change the setting from DHCP to STATIC IP.  You are still going to have an issue, because it will want you to select a Static IP address. Is this customer sure that the issue is what they are describing?  How does the PPP connection set an IP address? -Dave

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