[ECOS] EB40LS ping_test problem

Andrew Lunn andrew@lunn.ch
Sat Sep 20 20:52:00 GMT 2003


> >    I use ethernal to capture the packets.
> >    EB40LS first send ARP packet, and Linux reply.
> >    But EB40LS seems don't receive the reply packets, it resend the ARP
> >    packets.
> >    Where may be the problem??
> 
> Probably the receive part of the driver. Check to see if you are
> getting interrupts when it receives a packet. Then check what actually
> happens during the receive.
> 
>         Andrew
> 
> I enable the The CYGDBG_IO_ETH_DRIVERS_DEBUG,and set
> CYGDBG_IO_ETH_DRIVERS_DEBUG_VERBOSITY=2,
> I got the following message:
> Q1: In the first two packets, why it sends arp to 192.9.207.130?
>     The target is 192.9.207.130!

Its testing to see if there is another device using the IP address it
want to use. If there is another device, it will reply to the arp.

> Q2: Sending bytes is 42, who will do the padding to 60?
>     Because Linux got 60 bytes of arp.

The hardware. Ethernet packets must be at least 64 bytes in size,
including the CRC. Modern hardware will automatically pad the packet
as its sent, unless padding has been disabled.

> Q3: EB40LS got arp reply, but it don't send the icmp(ping),
>     it's just sending the arp out.

Back to my original question. Are you getting interrupts? Have you
checked what happens to the ARP reply? Is it dropped? Is an entry
added to the table? You need to do some real, hands on debugging
yourself. 

          Andrew

> =======================================================
>        hw_addr: 08:88:12:34:56:78
>      client IP: 192.9.207.130
>          my IP: 192.9.207.130
>      server IP: 192.9.207.120
>     gateway IP: 192.9.207.254
>   options:
>         subnet mask: 255.255.255.0
>        IP broadcast: 192.9.207.255
>             gateway: 192.9.207.254
> Sending 42 bytes
> xmit 42 bytes at 20f8c56 sg[1]
> 020F8C56: FF FF FF FF FF FF 08 88  12 34 56 78 08 06 00 01
> |.........4Vx....|
> 020F8C66: 08 00 06 04 00 01 08 88  12 34 56 78 C0 09 CF 82
> |.........4Vx....|
> 020F8C76: 00 00 00 00 00 00 C0 09  CF 82                    |..........
> |
> Sending 42 bytes
> xmit 42 bytes at 20f8bd6 sg[1]
> 020F8BD6: FF FF FF FF FF FF 08 88  12 34 56 78 08 06 00 01
> |.........4Vx....|
> 020F8BE6: 08 00 06 04 00 01 08 88  12 34 56 78 C0 09 CF 82
> |.........4Vx....|
> 020F8BF6: 00 00 00 00 00 00 C0 09  CF 82                    |..........
> |
> PING server 192.9.207.120
> Sending 42 bytes
> xmit 42 bytes at 20f8a56 sg[1]
> 020F8A56: FF FF FF FF FF FF 08 88  12 34 56 78 08 06 00 01
> |.........4Vx....|
> 020F8A66: 08 00 06 04 00 01 08 88  12 34 56 78 C0 09 CF 82
> |.........4Vx....|
> 020F8A76: 00 00 00 00 00 00 C0 09  CF 78                    |.........x
> |
> RxEvent - stat: 504, len: 60
> rx 14 bytes at 2128f74 sg[0]
> 02128F74: 08 88 12 34 56 78 00 50  BF 43 DD AC 08 06        |...4Vx.P.C....
> |
> rx 46 bytes at 20f89ac sg[1]
> 020F89AC: 00 01 08 00 06 04 00 02  00 50 BF 43 DD AC C0 09
> |.........P.C....|
> 020F89BC: CF 78 08 88 12 34 56 78  C0 09 CF 82 11 0A 11 75
> |.x...4Vx.......u|
> 020F89CC: C0 09 CF 78 00 8A 00 C3  00 00 20 46 43 45        |...x...... FCE
> |
> Tx event: 8
> recvfrom: Operation timed out
> --
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> 
> 
> 
> 

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