Subject: Re: connection bonding?
To: Steven M. Bellovin <smb@cs.columbia.edu>
From: None <jonathan@dsg.stanford.edu>
List: tech-net
Date: 12/07/2005 20:06:09
In message <20051208014223.107493C015F@berkshire.machshav.com>,
"Steven M. Bellovin" writes:
>In message <200512072235.RAA20918@Sparkle.Rodents.Montreal.QC.CA>, der Mouse wr
>ites:
>>
>>One of the most bothersome things about agr(4), to me, is that which
>>link a packet goes out seems to depend on nothing but a hash of
>>assorted data related to the packet.  This means that if links of
>>different speeds are aggregated, the slower one(s) will get overloaded.
>>I'd expect it to simply pick the interface with the shortest output
>>queue....
>>
>
>That's mostly a feature...

[.. discussion of TCP reordering and vendors who got it wrong ...]

Hi Steve,

In fact, it's more than a feature, it's a _requirement_.

IEEE 802.3ad requires that all packets (frames, in layer2-speak) in a
flow not be reordered (or htat they traverse the same path through a
link-aggreation group, I forget the exact wording, but the intent is
unmistakably clear. At least to anyone with our shared backgorund).