Hi group >From Cisco Website, there are sample questions for CCIE Qualification Exam. One of these questions is described below. I couldn't understand when the answer says : "Bridges cannot provide any form of flow control". Flow control is a function of Network Layer. Is this not a function of Data Link Layer , or Transport layer ? Why does the answer say Network layer ? Can anyone explain me this ? thanks a lot Henrique 6) Some disadvantages of bridging versus routing are: (more than one answer) a) Bridges cannot provide any form of flow control. b) Bridges cannot provide congestive feedback information to end nodes. c) Bridges offer no form of filtering. d) Bridges are more difficult to administer/maintain than routers. e) Bridges create more overhead traffic than routers. Answer for Question 6 a. Bridges cannot provide any form of flow control and b. Bridges cannot provide congestive feedback information to end nodes Flow Control and Congestive Feedback are functions of the Network layer. As bridges operate at the Data Link layer, these responsibilities fall to the end stations in a bridged environment. Most bridges do offer some filtering capabilities, at least on MAC addresses, and they are much simpler to administer. At first glance, it may appear that bridges create more overhead than routers, due to the BPDU frame that is sent out every second. However, these frames are very small compared to route advertisements sent out by routers, which can grow to be quite large in complex networks. Also, routers must tie Network addresses to Data Link addresses, which often creates more overhead (Example: IP ARP). Reference: Perlman, Interconnections, Chapter 12. ___________________________________ UPDATED Posting Guidelines: http://www.groupstudy.com/list/guide.html FAQ, list archives, and subscription info: http://www.groupstudy.com Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]