GroupStudy.com GroupStudy.com - A virtual community of network engineers
 Home  BookStore  StudyNotes  Links  Archives  StudyRooms  HelpWanted  Discounts  Login
RE: 802.10 / sde encapsulation [7:89484] posted 06/10/2004
[Chronological Index] [Thread Index] [Top] [Date Prev][Date Next] [Thread Prev][Thread Next]


802.10 is of historical interest only. It was actually a security standard,
according to IEEE, but IEEE withdrew the standard at some point since it was
rarely used. Cisco adopted it for use across FDDI trunks. In the olden days,
it was pretty common to connect 10 Mbps Ethernet LANs via a 100-Mbps FDDI
trunk using switches or bridges that had FDDI uplinks.

Because IEEE 802.10 specified a standard method for adding an extra little
header (meant for security purposes but never used), Cisco and other vendors
saw an opportunity to use it to incorporate a VLAN ID.

IEEE says a packet should have a MAC header, an LLC header, and then data.
IEEE 802.10 says MAC, LLC, 802.10, and then data. The Security Association
ID in the 802.10 is just right for fitting in a VLAN ID.

Back in the olden days, there really was no other standardized way to add
extra data-link-layer info. Now, of course, we have IEEE 802.1q. Also, Cisco
bought Kalpana at some point and started using ISL for Ethernet, which was
never standardized though.

As far as modern applications, there are none I would say. I wouldn't be
suprised to find some implementations of it in some old networks, but that's
due to inertia. Old technologies never really die. I saw a LocalTalk network
recently! :-)

Priscilla

brian wrote:
> 
> What would the modern day applications be for using sde
> encapsulation on an
> interface?  It seems like 802.10 (sde) was created for
> encrypting at the LLC
> layer, and then implemented by cisco as some sort of VLAN
> encapsulation
> method pre-dot1Q, and then also used in some bridging
> applications?
> 
> I've read the IEEE standard, and various cisco pages and google
> group posts,
> but I can't seem to put the puzzle pieces together to answer
> the question as
> to where one would use it in todays networks.  Is it still
> relevant or is it
> legacy?  Does anyone have any history of using 802.10?
> 
> -Brian
> 
> 


Message Posted at:
http://www.groupstudy.com/form/read.php?f=7&i=89491&t=89484
--------------------------------------------------
FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html