netdev - Re: 802.3ad bonding brain damaged?

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Date:	Mon, 08 Aug 2011 17:59:28 +0200
From:	Eric Dumazet <eric.dumazet@...il.com>
To:	David Lamparter <equinox@...c24.net>
Cc:	Phillip Susi <psusi@....rr.com>, netdev@...r.kernel.org
Subject: Re: 802.3ad bonding brain damaged?

Le lundi 08 août 2011 à 09:57 +0200, David Lamparter a écrit :
> Am Sonntag, den 07.08.2011, 15:52 -0400 schrieb Phillip Susi:
> > - From Documentation/networking/bonding.txt:
> > 
> > 	Additionally, the linux bonding 802.3ad implementation
> > 	distributes traffic by peer (using an XOR of MAC addresses),
> > 
> > This is counter to the entire point of 802.3ad. Distributing traffic by
> > hash of the destination address is poor mans load balancing for
> > systems not supporting 802.3ad. 
> 
> No, it isn't. 802.3ad/.1AX explicitly requires that no packet
> re-ordering may ever occur, which can only be guaranteed by enqueueing
> packets for one host on one TX interface. This behaviour is mandated by
> 802.1AX-2008 page 15 which reads:
> 
>   This standard does not mandate any particular distribution
>   algorithm(s); however, any distribution algorithm shall ensure that,
>   when frames are received by a Frame Collector as specified in 5.2.3,
>   the algorithm shall not cause
>   a) Misordering of frames that are part of any given conversation, or
>   b) Duplication of frames.
> | The above requirement to maintain frame ordering is met by ensuring
> | that all frames that compose a given conversation are transmitted on a
> | single link in the order that they are generated by the MAC Client;
>   hence, this requirement does not involve the addition (or
>   modification) of any information to the MAC frame, nor any buffering
>   or processing on the part of the corresponding Frame Collector in
>   order to reorder frames. This approach to the operation of the
>   distribution function permits a wide variety of distribution and load
>   balancing algorithms to be used, while also ensuring interoperability
>   between devices that adopt differing algorithms.
> 

It all depends on the definition of 'conversation'

Phillip assumed two (or more) TCP flows from machine A to machine B
could use two different links, while you assert they MUST use a single
link.



--
To unsubscribe from this list: send the line "unsubscribe netdev" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html