[En-Nut-Discussion] Re: ARP packets crashing the TCP stack

[Lloyd Bailey]

Hi Harald,

There is no specific message but a lot of ARP related messages. My 
specific problem is, ARP sent from 10.45.2.250 to 10.45.2.139
(Ethernut 2.1). A second ARP sent from 10.45.2.250 to 10.45.2.139 
(Ethernut 2.1). Ethernut board reset by watch dog timer, syslog
message sent to syslog server. Normal operation is resumed until the 
next ARP. Maybe it is a ARP cache problem. Or to do with the
sender address, our Linux server has multiple IP address and one MAC 
address. We are going to create a separate TCP segment for
our Ethernut project so this will not be a problem in the future.

Regards,

Lloyd.


No.     Time        Source                Destination           Protocol 
Info
     4 1.684859    10.45.2.250           10.45.2.139           ARP      
10.45.2.50 is at 00:0c:76:3c:bf:a8

Frame 4 (60 bytes on wire, 60 bytes captured)
   Arrival Time: May 17, 2006 09:06:26.137891000
   Time delta from previous packet: 1.684034000 seconds
   Time since reference or first frame: 1.684859000 seconds
   Frame Number: 4
   Packet Length: 60 bytes
   Capture Length: 60 bytes
   Protocols in frame: eth:arp
Ethernet II, Src: 10.45.2.250 (00:0c:76:3c:bf:a8), Dst: 10.45.2.139 
(00:06:98:21:0a:5e)
   Destination: 10.45.2.139 (00:06:98:21:0a:5e)
   Source: 10.45.2.250 (00:0c:76:3c:bf:a8)
   Type: ARP (0x0806)
   Trailer: 000000000000000000000000000000000000
Address Resolution Protocol (reply)
   Hardware type: Ethernet (0x0001)
   Protocol type: IP (0x0800)
   Hardware size: 6
   Protocol size: 4
   Opcode: reply (0x0002)
   Sender MAC address: 10.45.2.250 (00:0c:76:3c:bf:a8)
   Sender IP address: 10.45.2.50 (10.45.2.50)
   Target MAC address: 10.45.2.139 (00:06:98:21:0a:5e)
   Target IP address: 10.45.2.139 (10.45.2.139)

No.     Time        Source                Destination           Protocol 
Info
     5 8.190261    10.45.2.250           10.45.2.139           ARP      
10.45.2.50 is at 00:0c:76:3c:bf:a8

Frame 5 (60 bytes on wire, 60 bytes captured)
   Arrival Time: May 17, 2006 09:06:32.643293000
   Time delta from previous packet: 6.505402000 seconds
   Time since reference or first frame: 8.190261000 seconds
   Frame Number: 5
   Packet Length: 60 bytes
   Capture Length: 60 bytes
   Protocols in frame: eth:arp
Ethernet II, Src: 10.45.2.250 (00:0c:76:3c:bf:a8), Dst: 10.45.2.139 
(00:06:98:21:0a:5e)
   Destination: 10.45.2.139 (00:06:98:21:0a:5e)
   Source: 10.45.2.250 (00:0c:76:3c:bf:a8)
   Type: ARP (0x0806)
   Trailer: 000000000000000000000000000000000000
Address Resolution Protocol (reply)
   Hardware type: Ethernet (0x0001)
   Protocol type: IP (0x0800)
   Hardware size: 6
   Protocol size: 4
   Opcode: reply (0x0002)
   Sender MAC address: 10.45.2.250 (00:0c:76:3c:bf:a8)
   Sender IP address: 10.45.2.50 (10.45.2.50)
   Target MAC address: 10.45.2.139 (00:06:98:21:0a:5e)
   Target IP address: 10.45.2.139 (10.45.2.139)

No.     Time        Source                Destination           Protocol 
Info
     6 8.191241    10.45.2.139           10.45.2.50            Syslog   
USER.INFO: Jan  1 01:00:06 ethernut Eth...

Frame 6 (106 bytes on wire, 106 bytes captured)
   Arrival Time: May 17, 2006 09:06:32.644273000
   Time delta from previous packet: 0.000980000 seconds
   Time since reference or first frame: 8.191241000 seconds
   Frame Number: 6
   Packet Length: 106 bytes
   Capture Length: 106 bytes
   Protocols in frame: eth:ip:udp:syslog
Ethernet II, Src: 10.45.2.139 (00:06:98:21:0a:5e), Dst: 10.45.2.250 
(00:0c:76:3c:bf:a8)
   Destination: 10.45.2.250 (00:0c:76:3c:bf:a8)
   Source: 10.45.2.139 (00:06:98:21:0a:5e)
   Type: IP (0x0800)
Internet Protocol, Src: 10.45.2.139 (10.45.2.139), Dst: 10.45.2.50 
(10.45.2.50)
User Datagram Protocol, Src Port: syslog (514), Dst Port: syslog (514)
Syslog message: USER.INFO: Jan  1 01:00:06 ethernut Eth...
   0000 1... = Facility: USER - random user-level messages (1)
   .... .110 = Level: INFO - informational (6)
   Message: Jan  1 01:00:06 ethernut Etherdoor 0.7b - Nut/OS 4.1.5.4 pre



Lloyd Bailey wrote:

> Hi,
>
> ARP packets addressed to the Ethernut board (2.1) crashing the TCP 
> stack using Nut O/S 4.0.2, 4.0.3 and 4.1.5 pre.
> I see from previous messages that this is not a new problem. Is anyone 
> working on it?
>
> Regards,
>
> Lloyd.
>

-- 
IT-afdelingen
Pharma Nord
Sadelmagervej 30-32
7100 Vejle
Denmark
Tel:. +45 75 85 74 00