Subject: AARP corruption/netatalk

From: Alistair Riddell <[email-masked]>
Date: Fri, 11 Feb 2000 19:00:10 +0000 (GMT)

I have an annoying problem.

I use Netatalk to serve files to a network of around 400 macs. From time
to time the netatalk server disappears from the chooser. I have traced
this to the AARP entries cached in the server not matching the actual
address of the machines. 

Typically the machine's hardware address shows in /proc/net/aarp but the
corresponding AppleTalk address does not match that found in the AppleTalk
control panel.

The annoying thing is there is no way that I can see of flushing/altering
/proc/net/aarp without killing netatalk and doing rmmod
appletalk. Obviously this is undesirable.

Some more details:

Server is running netatalk pre-asun2.1.4-37b.tar.gz; Linux kernel
2.3.42. However the problem has been present for some time even when using
older netatalkd and kernel 2.2.

machine is a dual-processor PIII; network card is a 3Com 3c905b plugged
into a 3com CoreBuilder 3500 switch, which is configured as an AppleTalk
router.

Only machines in the same zone as the server have problems; other machines
don't presumably because the 3500 router does the AARP stuff.

These problems do not affect TCP/IP connectivity; I can ping both ways
to/from affected machines and I can connect to the server by entering its
IP address in the chooser.

This only appears to affect a handful of machines at once.

Although the network range is a single number there are nothing like 254
machines in that network - the others are on the other side of the router.

My /etc/atalkd/atalkd.conf looks like this:

eth0 -phase 2 -net 12 -addr 12.152 -zone "Senior School South"

I would be grateful for any suggestions.

-- 
Alistair Riddell - BOFH
IT Support Department, George Watson's College, Edinburgh
Tel: +44 131 447 7931 Ext 176       Fax: +44 131 452 8594
Microsoft - because god hates us

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From: Quant-X UNIX and Linux Support <[email-masked]>
Date: Mon, 14 Feb 2000 17:54:32 +0100

Hello,

I think that you should send this to the linux-kernel list as the code
which handles AARP resides in the kernel.  This sounds like a serious
problem to me.  Perhaps it could have much consequences much worse than
disappearing from the chooser.  Anybody else seen it?

I'm afraid that otherwise I can't offer much help to you.  AARP doesn't
smell good (by design).  Too many broadcasts.  Well, if this is not
happening at many installations I guess that some things are getting
lost on your network.  Perhaps you can check cables and if the network
is OK in general.  Is it that the server disappears only from certain
Macs?

Best regards,

Dejan

-- 

Dejan Muhamedagic   mailto:[email-masked]
UNIX and Linux Support   mailto:[email-masked]

Quant-X Service & Consulting Ges.m.b.H.  http://www.quant-x.com
Phn: +43 4212 90555-0     Fax: 90555-20    Free: +800 90555 000

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From: Harry Zink/Netatalk List <[email-masked]>
Date: Mon, 14 Feb 2000 10:52:39 -0800

>> this to the AARP entries cached in the server not matching the actual

This has become so common to me, that I don't even notice it anymore.

This is, of course, NOT a good sign, and I'm surprised so few other people
have either noticed it, or pointed it out.

Are there any plans to fix this, since an AppleShare server should,
obviously, not make a habit of dropping off the network.

Harry

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From: Jay Palat <[email-masked]>
Date: Mon, 14 Feb 2000 14:39:46 -0500 (EST)

I think I've been seeing something similar but I'm not
sure if it's related.  

I run off of a small environment (10 Macs). Recently we've
been having problems with our G3 Based Macs and iMacs changing
identities.  The netatalk server stays, but workstations
disappear.  Or they map incorrectly (Machine X and Machine Y both
map to Machine X).  

Is this netatalk related or is something completely different?

Jay

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From: Alistair Riddell <[email-masked]>
Date: Mon, 14 Feb 2000 21:53:33 +0000 (GMT)

> disappearing from the chooser.  Anybody else seen it?

I will do that. I don't think the conseqences are any worse than a loss of
connectivity - I can see no way that data corruption can result.

> is OK in general.  Is it that the server disappears only from certain

I have no reason to suspect the network. It carries tens of gigabytes of
traffic every day with no other problems. The server in question handles
several other IP-based services with no problems. I have no reason to
suspect the server hardware since the problem has existed since before the
machine was replaced a couple of months ago.

The problem is limited to machines on the same subnet as the server. It
does not appear to be limited to any particular model or OS version, and
only happens to one or maybe two out of the 100 or so machines in that
subnet.

The problem cannot be reproduced on demand. I guess the next step is to
plug a packet sniffer in and capture all the aarp packets for a while.

Ali

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From: Quant-X UNIX and Linux Support <[email-masked]>
Date: Thu, 17 Feb 2000 11:26:28 +0100

Hello,

> connectivity - I can see no way that data corruption can result.

As somebody mentioned that on FreeBSD there are no such problems it may
really be a problem of the kernel code.  If it's appearing only randomly
and if it's not a serious issue it might as well have passed unnoticed.

On another note, couldn't loss of connectivity also mean lost session?
Or is this the thing happening only while in Chooser?

Cheers.

Dejan

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