Kaminski, Shawn G wrote: > > If I remember correctly, when a node wants to become the new > active monitor, > it will transmit a claim token frame. The node with the highest > MAC address > becomes the active monitor.
Actually FDDI doesn't have an active monitor like Token Ring does. But the concepts are similar. Each station monitors the ring for inactivity, lost tokens, or reconfigurations that indicate a need to initialize or reinitialize the ring. A station detecting the need to initialize the ring sends Claim Frames with its Target Token Rotation Timer (TTRT) in the MAC data. When a station receives a Claim Frame, it compres the TTRT in the frame with its own TTRT. If the TTRT is lower than the station's TTRT, the station yields and just repeats the Claim Frame. If a station receives a Claim Frame with a higher TTRT, the station abosrbs the incoming Claim Frame and sends its own. The station with the lowest TTRT will be the only station that receives its own Claim Frame. This station has the right to define the Operational Token Holding Timer. It initializes the ring by sending the first free token. (If two stations have the same TTRT, the sation with the higher MAC address wins the bidding process.) If you are seeing lots of Claim Frames and no data, then after a while you'll see Beacon Frames. Just like with Token Ring, you can determine a Fault Domain, but it's not quite as easy as Token Ring. You'll have too look at Station Management Neighborhood Information Frames to determine a station's upstream neighbor. Anyway, the problem exists in the station sending the Beacons, its upstream neighbor, or cabing between them, just like with Token Ring. With no info on how your interface is connected, we can't tell you much, but you probably have a physical layer problem with the station complaining or its upstream neighbor. _______________________________ Priscilla Oppenheimer www.troubleshootingnetworks.com www.priscilla.com > > I'm assuming you're talking about a FDDI concentrator port. One > possibility > would be bad link quality. > > Shawn K. > > -----Original Message----- > From: JJ Angleton [mailto:cciewanabee@;yahoo.com] > Sent: Wednesday, November 13, 2002 1:04 PM > To: [EMAIL PROTECTED] > Subject: FDDI failure - up for a while, then takes a nap > [7:57367] > > > What would cause a FDDI interface to be up for a little while, > and then > fail? > > In a potentially related question, what's a claim frame? > > > > > > --------------------------------- > Do you Yahoo!? > U2 on LAUNCH - Exclusive medley & videos from Greatest Hits CD > > Message Posted at: http://www.groupstudy.com/form/read.php?f=7&i=57378&t=57367 -------------------------------------------------- FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
