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RE: First packet sent?
- To: "'eCos discussion'" <ecos-discuss at sources dot redhat dot com>
- Subject: [ECOS] RE: First packet sent?
- From: "Trenton D. Adams" <tadams at theone dot dnsalias dot com>
- Date: Thu, 18 Oct 2001 12:49:56 -0600
Resolved!
The first packet is an ARP as I suspected. I wasn't sure until I looked
in the TCP/IP Redbook and it says that an ether type of 0x0806 is an
ARP. Correct me if I'm wrong, most of the things I said, however
convoluted, are true! ;) What a good guesser I am! LOL
p.s.
You may receive this message before the original because the redhat
server was having troubles and my original hasn't gotten through yet.
At least not to me anyhow.
> -----Original Message-----
> From: Trenton D. Adams [mailto:tadams@theone.dnsalias.com]
> Sent: October 18, 2001 10:04 AM
> To: 'eCos discussion'
> Subject: First packet sent?
>
>
> What is the first packet sent when an ethernet interface
> comes up? Mine appears to be 42 bytes in length. I see my
> MAC address and IP address twice, but I don't know what the
> other numbers represent.
>
> MAC: 0002 2D2B 8B76 0806
> IP: AC10 011E
>
> I've got the interface configured for a static IP
>
> Sending 42 bytes
> xmit 42 bytes at a4bd6 sg[1]
> 000A4BD6: FFFF FFFF FFFF 0002 2D2B 8B76 0806 0001
> |........-+.v....|
> 000A4BE6: 0800 0604 0001 0002 2D2B 8B76 AC10 011E
> |........-+.v....|
> 000A4BF6: 0000 0000 0000 AC10 011E
> |.......... |
> WVLAN - RX - status = 8089
> rx 14 bytes at d555c sg[0]
> 000D555C: FFFF FFFF FFFF 0050 BA48 821B 0800
> |.......P.H.... |
> rx 78 bytes at a4c20 sg[1]
> 000A4C20: 4500 004E 5BAD 0000 8011 83D1 AC10 0101
> |E..N[...........|
> 000A4C30: AC10 01FF 0089 0089 003A 4A7E EE52 0110
> |.........:J~.R..|
> 000A4C40: 0001 0000 0000 0000 2045 4646 4946 4546
> |........ EFFIFEF|
> 000A4C50: 4345 4645 4E45 4643 4143 4143 4143 4143
> |CEFENEFCACACACAC|
> 000A4C60: 4143 4143 4143 4142 4C00 0020 0001
> |ACACACABL.. .. |
>
> I don't know what the first transmit packet is.
>
> I don't know what the First RX packet is, but it has the
> server MAC address of 0050 BA48 821B
>
> The second RX packet is a broadcast packet from our server at
> AC10 0101
>
> Is the first RX packet a "next packet is from this MAC
> address" packet? If so, is the FFFF FFFF FFFF a MAC
> broadcast address indicating this packet and the next
> protocol packet is a broadcast packet (AC10 01FF)?
>
>
> Trenton D. Adams
> Extreme Engineering
> #17, 6025 - 12 St. SE
> Calgary, Alberta, Canada
> T2H 2K1
>
> Phone: 403 640 9494 ext-208
> Fax: 403 640 9599
>
http://www.extremeeng.com