--- title: "DATA SENT IN SEND MAC COMMAND BUT NOT SEND COMMAND" url: "https://maker.wiznet.io/forum/14603" markdown_url: "https://maker.wiznet.io/forum/14603/md" type: "Forum topic" category: "Ethernet Chips" author: "Abraham George" created: "2022-08-01T07:55:51+09:00" last_activity: "2023-01-05T18:35:53+09:00" language: "en" views: 314 replies: 2 source: "WIZnet Makers forum (https://maker.wiznet.io/forum/)" --- # DATA SENT IN SEND MAC COMMAND BUT NOT SEND COMMAND ## Question Asked by Abraham George on 2022-08-01 in Ethernet Chips. Hello, I encountered a situation where the data was being successfully sent when using the send mac (x"21") command but the data is not sending when I used the send command (x"20) it just sends a stream of zeros as shown in figure [![send mac](https://maker.wiznet.io/forum_uploads/wiznet/original/2X/8/8333f7440c5d55014241770b04083dbf07c5de6e.png) send mac1920×1080 192 KB](https://maker.wiznet.io/forum_uploads/wiznet/original/2X/8/8333f7440c5d55014241770b04083dbf07c5de6e.png) [![send](https://maker.wiznet.io/forum_uploads/wiznet/original/2X/9/9fe4e7a4f99cc57aac0e9e97f016671b4db8a7b2.png) send1920×1080 201 KB](https://maker.wiznet.io/forum_uploads/wiznet/original/2X/9/9fe4e7a4f99cc57aac0e9e97f016671b4db8a7b2.png) can anyone help me understand why this is happening? Regards, Abraham George ## Replies ### Reply 1 by Eugeny, 2022-08-11 Sending to remote port 0 seems to be invalid operation. Sending to MAC 00:00:00:00:00:00 does not look like proper too. Therefore I would question if your first picture with “data” is showing a valid behavior, and is having valid data you intended to send. What data are you actually sending/expecting to see? ### Reply 2 by Jay Jagani, 2023-01-05 (in reply to reply 1) I am having the same exact problem. When I use SEND_MAC, my udp packets send fine, but when I use the SEND command, the automatic ARP process does not seem to work. I have another topic posted here with more information: --- Source: https://maker.wiznet.io/forum/14603