Change count & Route Table clearing

Subramanian Kuppusamy, Noida subramaniank at
Tue Aug 31 19:04:37 PDT 2004

* From the T10 Reflector (t10 at, posted by:
* "Subramanian Kuppusamy, Noida" <subramaniank at>
I am new to this group. I have some basic doubts in Annex-K of SAS 1.1 specs

1. If I correclty understood Changecount value is checked by the intiator
only for the top most Expander or the Hub expander.
   From the specification,Changecount value is incremented in an Expander
device only if it initiates a Broadcast(Change). So if a Broadcast(Change)
is initiated by some Expander somewhere in same SAS Domain, the topmost
expander will just forward the Broadcast(Change). 
  In this case obviously the changecount value of topmost expander is not
changed. Then Why this changecount value check is needed after completing
the configuration of route table?

2. How the routing table in all the configurable expander devices are
cleared before starting rediscover process for some reason.
   It is ok for a self configuring expander as it may handle with some
internal function. But for other configurable expander devices How the route
table is cleared? 
  Am I missing any SMP Request function meant for this??

Any input on this will be helpful

Thanks & Regards
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