[ECOS] RE : [ECOS] Duplicate ARP table entries
Wed Nov 10 01:54:00 GMT 2004
Actually we see this problem on units with a non-Ethernet version of Redboot as well as units where we pull the MAC from the same location (no fconfig involved with our modified ethernet driver.)
Also the problem can occur after it's been working just fine and then sits idle for 20+ minutes. The ARP entries time out after 20 minutes so it seems related to ARPs being generated from the device and the host such that I end up with 2 duplicate entries in the table - one that gets updated by ARP responses and the other that gets used by ether_output.
From: Gary Thomas [mailto:email@example.com]
Sent: Tuesday, November 09, 2004 11:09 AM
To: Arnaud Chataignier
Cc: Jeff Duncan; firstname.lastname@example.org
Subject: Re: [ECOS] RE : [ECOS] Duplicate ARP table entries
On Tue, 2004-11-09 at 10:14, Arnaud Chataignier wrote:
> I confirm the bug. I see it also frequently, but unfortunately I
> hadn't had time to dig into the problem yet.
> What I do as a temporary patch for the moment is to set the ARP entry
> manually on host side, so that it doesn't generate an ARP request. May
> be it can help you for a while...
> But for sure this bug needs to be fixed for a use in a real product. I
> woudl appreciate receiving the patch if you find the solution before I
This can happen if your eCos application uses a different ESA (ethernet hardware address) than what RedBoot does. I have seen this - it happens when the 'fconfig' data isn't set up quite correctly.
> -----Message d'origine-----
> De : email@example.com
> [mailto:firstname.lastname@example.org] De la part de Jeff
> Duncan Envoyé : mardi 9 novembre 2004 17:49
> À : email@example.com
> Objet : [ECOS] Duplicate ARP table entries
> I'm looking for some insight into a problems I am seeing. Using the
> latest eCos with FreeBSD stack on an Arm9 connecting directly to a PC,
> I sometimes get into a situation where communication (such as ping)
> fails. Looking into it further I have found that there seem to be
> duplicate entries in the Arp table. The ethernet output resolves to
> one entry that has expired triggering an Arp send. When the Arp
> response is received, a different Arp table entry is updated with the
> new Arp timeout. So what I end up with is a ping request from the
> host, a response being generated from ICMP, and a new Arp request
> coming out of the device.
> Sometimes I can fix the problem by clearing the route table and
> initializing the connection again.
> Any ideas?
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> and search the list archive: http://ecos.sourceware.org/ml/ecos-discuss
Gary Thomas <firstname.lastname@example.org>
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