The guides were a great learning experience to me with a lot of practically useful well explained details. The following comment I sent a few times to Cisco Press - they invite you to do so at the beginning of the book - to which I never ever got a reply which is a bit disappointing for a publisher of such great books. Users who study these books may check if my findings are right. ;-)

When studying the guides I came across a section which I think does not accurately describe what is being tried to explain. It concerns the text on page 252 till the section 'Verifying the Initial Configuration of a Catalyst Switch'. Below I will try to explain what I mean by referring to the text in the book and then giving my comments between square brackets.

The first line on the page I think describes what is being explained in the following paragraphs:
'Switching tables can have more than one MAC address mapped to a particular port'.

In the fourth paragraph I think lines 2, 3 and 4 are not accurate. 'The data frame is forwarded to Switch B on Port 2 [in the last line of the previous (3rd) paragraph a Port is referred to alphabetically - Port A. I would prefer consistency here]. Switch 2 [with Switch 2 I think Switch B is meant. Please see my previous comment on Port 2 / Port A] looks up the switching table and recognizes the destination MAC address. It [I presume Switch B is meant here] sends the frame to Host F, with MAC address F, via Port 4. [the latter implies that Host F is connected to Port 4 on Switch B. This is important to remember for the following paragraphs. As far as I'm aware it is still not known with which Port on Switch B the connection is made with Switch A]

When Host F replies to Host A, the procedure is reversed. Host A [I think Switch A is meant here] can now update the switching table by mapping Host F to Port 4 [I think that for Switch A data traffic destined for Host F which resides on Switch B, should go to Port 2 because this is the port on Switch A to which Switch B is connected]. Switch 2 [or Switch B] can now update the switching table by mapping Host A to Port 2. [this implies that Switch A is connected to Switch B at Port 2 of Switch B. Following the sequence of the data traffic I think that first Switch B can update its switching table after receiving a data frame from Host A on the port which connects Switch B with Switch A. Secondly after Host F replies [then indeed the procedure is reversed) Switch A can update its switching table with the information that data frames for Host F should go to Port 2 of Switch A].

Eventually, Switch A will learn that Host D, Host E and Host F are mapped to Port 4. [this contradicts with the 4th paragraph where it is indicated that the data frame (for Host F) is forwarded to Switch B on port 2 (of Switch A) and Switch B will learn that Host A, Host B and Host C are mapped to Port 2. [if my conclusion at the end of the previous paragraph is correct then this is correct].

Summarised:
1) Port and Switch indication are not consistent A and 1, B and 2 are confused.
2) Port numbers are not accurately used. My understanding of 'Switching tables can have more than one MAC address mapped to a particular port' is as follows. When Switch A and Switch B are connected with each other via Port 2 (Switch A) and Port 3 (Switch B) then data frames sent from Hosts connected to Switch A to Hosts connected to Switch B will be forwarded to Switch B via Port 2 of Switch A. Data frames sent from Hosts connected to Switch B destined for Hosts connected to Switch A will be forwarded to Switch A via port 3 of Switch B.

Clear and concise. I couldn't have completed program without it.