# socket for detection UDP-based protocol

**URL:** <https://forums.digi.com/t/socket-for-detection-udp-based-protocol/5647>\
**Category:** NET+OS\
**Created:** [July 24, 2007, 4:18pm UTC](https://forums.digi.com/t/socket-for-detection-udp-based-protocol/5647 "2007-07-24T16:18:51Z")\
**Posts on this page:** 2\
**Page:** 1

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**Author:** ![pevandenburie](https://avatars.discourse-cdn.com/v4/letter/p/7feea3/32.png) [@pevandenburie](https://forums.digi.com/u/pevandenburie)\
**Post date:** [July 24, 2007, 4:18pm UTC](https://forums.digi.com/t/socket-for-detection-udp-based-protocol/5647/1 "2007-07-24T16:18:51Z")

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Hi,  
I made a Windows tool to discover DIGIs on the network using UDP messages, even when they are in AutoIp mode and the IP doesn’t match with the computer IP.

My problem is the following:  
If computer IP is 192.168.10.157 and the DIGI is 169.254.10.20 (retrieved from AutoIP), the DIGI receive the message but doesn’t want to send back the answer (error #118, Host is unreachable).

It works well if the DIGI is in the same subnet.  
It worked well too when I was using FastIp API in NETOS60F, which is no more available.

I tried the “SO\_DONTROUTE” socket option or the MSG\_DONTROUTE flag, but it doesn’t work. Do you know how to do?

Thanks for your information…

Paul

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**Author:** ![charliek](https://avatars.discourse-cdn.com/v4/letter/c/94ad74/32.png) [@charliek](https://forums.digi.com/u/charliek)\
**Post date:** [July 26, 2007, 2:06pm UTC](https://forums.digi.com/t/socket-for-detection-udp-based-protocol/5647/2 "2007-07-26T14:06:44Z")

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You could use the Ethernet Bypass function to put the data on the wire directly.