Re: ARP flux vs. weak/strong ES model

Lewis G Rosenthal <[email protected]> Fri, 15 Feb 2019 21:23:06 +0000
Newsgroups org.kernel.vger.lartc
Message-ID <[email protected]>
Hi, Erik...

Erik Auerswald wrote:
> Hi,
>
> On 2/14/19 17:21, Grant Taylor wrote:
>> On 02/14/2019 01:31 AM, Erik Auerswald wrote:

<huge snip>

> Linux's cavalier default behaviour in answering ARP requests might be 
> motivated by the weak ES model in helping other systems on the LAN 
> reach the Linux server, even if they use an IP address assigned to 
> another LAN the Linux server is connected to. Thus the problem of "ARP 
> flux" is probably closely related to how Linux implements the weak ES 
> model, but not necessarily to the weak ES model itself as described in 
> RFC 1122.
>
> Thus I argue that using "ARP flux" to describe the ARP problem 
> observed with Linux is preferable to attributing the problems to 
> Linux's implementation of the weak ES model.
>
> Please note that I have not searched for the origin or an 
> authoritative source on "ARP flux", and cannot guarantee that it is 
> indeed consistently used to describe the aforementioned problem. But 
> it did turn up on related web searches, and seems to directly refer to 
> the ARP problem at hand.
>
> Sorry for being pedantic.
>

Thanks so much for a very cogent explanation of the difference. I'd been 
meaning to do some digging since spying this thread scrolling by. One of 
the things I like best about this list is the way it makes me scratch my 
head. Usually, someone else comes up with a good answer before I'm done 
scratching, which is another thing I like. :-)

Some interesting discussion of the Linux ARP flux problem, here (2.1.4 
et seq):

http://linux-ip.net/html/ether-arp.html

Linked from there, and perhaps relevant to the original problem:

http://ja.ssi.bg/#iparp

(I guess I should probably push those to the original thread.)

-- 
Lewis
-------------------------------------------------------------
Lewis G Rosenthal, CNA, CLP, CLE, CWTS, EA
Rosenthal & Rosenthal, LLC                www.2rosenthals.com
visit my IT blog                www.2rosenthals.net/wordpress
-------------------------------------------------------------