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Hi,
Keil Ethernet stack
I have trouble using static address when If I cannot find DHCP Server. I enable Dynamic Host Configuration in Net_Config_ETH_0.h I also specified my static ip address==192.168.0.100 and static Default Gateway =192.168.0.1. Primary DNS Gateway =192.168.0.1.
I am connecting directly my Embedded device ethernet to PC. My PC has static IP address = 192.168.0.1
If I disable Dynamic Host Configuration in Net_Config_ETH_0.h then it all works.
I thought If it cannot find DHCP server it will fallback back to using static DNS server which is my PC.
Kindly suggest what is wrong with my configuration. Does Keil Ethernet stack supports fallback?
Thanks, Naeem
If the Windows machine isn't networked then you have no use for a gw address since the Win machine can't forward data.
So what do you want to do on that local link?
Note that IPv6 supports link-local IP numbers. But what is practical so much depends on what your device is expected to do. Or what the Win machine is expected to do with it. You might also have seen how MS (and then others) started to take random 169.x.x.x addresses if no DHCP IP gets assigned.
The PC can communicate with your device without any IP assigned - the actual transfers aren't based on IP numbers but on hw (MAC) addresses. The IP is just there for routing and to look up the hw address of a device.
What meant was does Keil TCP/IP Stack supports AUTOIP if DHCP is enabled and not found then fall-back to use static IP Address.
lwIP stack supports it.
lwip.wikia.com/.../AUTOIP
I have only 128k RAM. If I enable TCP/IP Debug. then my embedded device stops working.
It looks like Keil TCP/IP stack supports AutoIP
www.keil.com/.../group__using__ethernet__interfaces__ipv4__assign.html
I will try this out.
But you do notice the huge difference of the Auto IP mode compared to your original post where you have set a hard-coded IP + GW to use if no DHCP server supplies an IP?
It works AUTOIP
If I specified these addresses in Net_Config.h
My Embedded device IP Address = 169.254.1.0 The network mask = 255.255.0.0 Default Gateway = 169.254.254.255
Connect directly to Computer/Laptop running Windows vista/7
I put my Windows machine IP Address = 169.254.254.255 The network mask = 255.255.0.0
Are you really sure you understand AutoIP?
What do you think this sentence means? "The default gateway is not assigned, because it is not known."
How would that combine with your own statement: "Default Gateway = 169.254.254.255"
I know these functions to enable and disable DHCP which are "netDHCP_Enable" and "netDHCP_Disable".
But I cannot find function to find current settings DHCP is enable or disable.
Errr ... it's your application that's controlling the state? and you can't figure out how to keep a record of what you set it to? OMG!
ok, I guess I need to keep DHCP is enable or disable setting in my variable.
Since you would need some kind of state machine to decide when you want to enable or disable, it would be logical that the state machine also knows the current state so it knows what look for to decide if it should switch state.
Hi Per Westermark,
I need to give user option to enable or disable DHCP and show current DHCP state on my GUI(Web page).
When my embedded device will start. I think I can find if DHCP is enable or disable by callback
netDHCP_Notify
www.keil.com/.../group__ethernet__interface__callbacks.html
Or I can always called DHCP enable in my setup
and I will save current settings into my variable.
When user change DHCP enable/disable from GUI(Web page). I can call netDHCP_Disable or netDHCP_Enable and save current state in my variable.
Is this good solution?
No, you don't. Because by the time anyone is even able to see that GUI, the issue will already be entirely moot. That would work about as well as putting the switch for the ceiling light in a place where you cannot find it without the ceiling light on.
I am still confused how to use Auto IP of ARM with Windows 7 .
http://www.keil.com/forum/60356/
It is working only If
My Embedded device IP Address = 169.254.1.0 The network mask = 255.255.0.0 Default Gateway = 169.254.254.255 Connect directly to Computer/Laptop running Windows vista/7 I put my Windows machine IP Address = 169.254.254.255 The network mask = 255.255.0.0
My Embedded device IP Address is assigned IP address automatically above case.
I do not want to use static IP addresses for Auto IP when DHCP is not found.
I need to use automatically assign IP address for my My Embedded device and Windows 7 machine.
Let me know how I can do it with example.
Why do you - in this thread - post a link pointing back to this very thread?
M$ has documentation how to use APIPA for Windows 7. All you need to do is to say that the primary setting should have an IP automatically assigned. Then as alternative configuration you keep the default APIPA setting checked. 30 seconds with Google...
But it is only relevant if you want to create a local island of non-connected machines. So friend A and friend B can connect their two computers together without any DHCP server.
So it might be practical in a tent out in the wilderness. But most people have an existing network with at least a dirt-cheap router - and suddenly do not need APIPA.
So - how have you ended up in a situation where you want your device and your Windows machine to be part of a local networking island? Remember that with APIPA you aren't expected to have a gateway, since the router that supplied that gateway would normally have been able to supply a working DHCP service, negating any need for APIPA.
I need to use Auto IP. as My Windows PC is connected via ethernet directlty to my embedde devuce. No internet, no router . Router is optional.
Just need to specify Windows 7 to enable Auto IP. which I can see is working using ipconfig. but It does not pick Embedded device IP address or via device name.
I enabled DHCP as well.
I do not want to specified any static IP address for device and any other address.
http://www.keil.com/support/man/docs/rlarm/rlarm_tn_cfgeth.htm
It works in DHCP case via router but not in Auto IP mode.
I can't see any mention of version.
Looks like you're doing something wrong. Keil introduced the autoip feature into their stack a few years back. it uses it after a dhcp timeout. At the time, i asked them if it could be disabled and they said it couldn't.
It still works as I saw it work back then.