Q & A on Repeaters in Ethernet Networks Q: We are using "Computer Networks and Internets", Second Edition, here at the US Naval Academy. My class had a question about bridges. In Chapter 10, p 130, Ethernet will not operate correctly if more than four repeaters separate any pair of stations. A: Actually, the text was in error: the Ethernet specification says at most *two* repeaters can separate any pair of stations. You can find errata at: http://www.cs.purdue.edu/homes/dec/net+inet.errata.html You will also see pointers to corrected pages in postscript. Q: Is this true for bridges? We looked at Figure 10.8 on p 138 and saw five bridges separating the farthest pair. A: There is no theoretical limit on the number of bridges. In practice, of course, there are reasons to limit the size. By the time one sends through many bridges, delay starts to become noticeable. Also, the segments that are interconnected with bridges contain many computers, broadcast traffic can become a problem (bridges send a copy to all segments). Finally, because most organizations arrange their networks in a hierarchy (i.e. a backbone, bridges connecting the next level, and bridges connecting a third level), only four bridges lie between any two hosts.