NetBurner Community Forum

I am working with a 3rd party that has implemented a partial UDP protocol in an embedded device. The protocol does not support ARP. They have requested that we disable ARP broadcasts on our side.

The MOD54417 is configured as two independent ports - not a switch. One of the ports is connected to the 3rd party device - and only that device. Is there a way to disable ARP on one of the Ethernet ports?

TIA
Scott

Just out of curiosity, why wouldn't their protocol just ignore them? Seems like anyone using their software would need to modify the source code of whatever tcp/ip stack they are using. I think there are configuration settings to disable an arp cache on some operating systems, but the arp requests would still go out. What does this software do?

1) It is a prototype system. They were given a low budget to develop it. They had to implement a UDP Protocol from scratch in an embedded system.
2) There has been a change in staff in my company. I inherited this project after an employee left. My predecessor told them that they would not need to implement ARP since their device will be directly connected to a NetBurner. No other devices would be attached to that Ethernet port. Obviously, neither my predecessor or the 3rd party knew the consequences and both assumed that ARP could be disabled on the NetBurner side.

So I am looking for a simple Yes or No answer. Can the ARP for a single Ethernet port be disabled via the NetBurner API? If not, the 3rd party needs to modify their side to handle the ARP messages.

BTW, I agree with you. They should be able to handle the ARP and basically ignore the message.

Short answer: Yes. Anything is possible.

Long answer: Maybe... What's your requirement for turning off ARP? No ARP message ever goes out that port or you need to not ARP for the directly connected device?

There's no built in capability to disable ARP for a given interface in the source at the moment. It would be fairly trivial to add the ability to set static entries into the ARP table. It would be feasible to disable interfaces, but a little harder...

-Dan

Requirement: No ARP messages broadcast on a specific interface.

If the separate interface is on a separate subnet from the other interface.
You don't turn on autoip and you add a static ARP entry and the only address you ever send to on the
separate interface subnet is the one in the static arp entry, it will send no ARP's.


Setting a static Arp entry is not something we currently support, but I think Dan is about to add that and post the changes here....

You could also replace all of the TransmitBuffer calls in arp.cpp with something that filters the interface number and
just frees the buffer if its sent to the wrong interface....

If you misconfigure your code lots of other stuff could go out the interfce such as tcp packets, multicast joins and a whole bunch of other things other than the UDP packets you want and the arps you just killed...

Paul

Send a support request in and we'll get you the Static ARP entry change.

-Dan

A support ticket has been submitted.

If the separate interface is on a separate subnet from the other interface.
You don't turn on autoip and you add a static ARP entry and the only address you ever send to on the
separate interface subnet is the one in the static arp entry, it will send no ARP's.

This will work for me.

Thanks,
Scott