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Ping to public ip not working


I have connected a ChipX to a public IP.
Inside my office on the intranet IP Address every thing works fine.
But if I connect it using the public IP the ping does not respond

26:44:Et:Assigning Static IP
26:44:Et:Assigning Static DNS:
26:44:Et:IP: <= static public IP I have
26:44:Et:Subnet Mask:

But this same code works with public IP on EMX board.

In the code I am assigning a MAC address. Does that create issues for ChipX. Does the Ethernet controller have its own MAC address, which is not matching with the TCP/Ip stack etc…


The MAC you set on ChipworkX will be the same for its software stack and for hardware


I still then do not understand why EMX works and ChipX does not work.
is there anything I can do to debug this


Do you have a correct and valid MAC on both boards?

Use the same MAC on EMX and CWX and it will probably work on both.


I set the same MAC on both EMX and ChipX.
Just to be sure. and it did not work.

That is where I thought the Etherent contoller on ChipX is not taking it.
But if you tell the Etherent contoller on ChipX takes it, then that is not the case

The MAC is


So you have the exact same network settings on EMX adn on ChipworkX. When you connect EMX to the network with a public IP, you can ping the IP address from the internet. If you disconnect EMX then connect ChipworkX, you can not ping that IP address from the internet.

Are you sure that ChipworkX Ethernet is working at all?


ChipX ethernet it is working, because if I change it to a local IP in my network.

I can connect


Is it something to do with

Subnet Mask:

would you guys tested it.

We tried at a differnt site. ANd it is also not working


[quote]Is it something to do with

Subnet Mask:
How do you know it is the mask?


so since you started talking about network masks, you have to be more specific about the public network address range you’re using, how you’re PINGing the device (like what the PC’s network setup is), and how the network is routed. You don’t need to tell us the EXACT network addresses, but you need to make sure you tell us the “relative” network addresses for the default gateway, the test PC and the ChipworkX device. Even if you use 10.x.x.x which isn’t public, and just tell us your device’s details.

To me it sounds like your network routing isn’t working as you expect - a couple of causes are:

  • The subnet mask is not the correct subnet mask to use for the network the device is on. [ That is a single Class A address block that is not routed - that’s 16.5 million addresses in a switched network, is that really what you have?! ]
  • You’re testing across a router/firewall that is blocking ICMP.
  • The default gateway you have set on ChipX is not working as expected.

If you tell us how the netowkring bits are set up we can tell you how it should work and then where to look for issues. The fact that it does work when you have a different network setup on your internal network points to a small change on the network being all that’s needed but to get it right we need more info.