2 Intern

 • 

812 Posts

November 18th, 2004 12:00

Yes, flapping refers to a port that is repeatedly going up and down. This is typically a physical layer problem caused by cables, drivers, etc.

2 Intern

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812 Posts

November 18th, 2004 12:00

I am not able to access the link you posted. Our proxy does not allow me to access external web pages using IP address for security reasons.

39 Posts

November 18th, 2004 12:00

I'll try to paste a snippet here:

18-Nov-2004 08:48:43  Informational %STP-I-PORTSTATUS: Port 2/e40: STP status Forwarding

18-Nov-2004 08:48:12  Informational %LINK-I-Up: 2/e40

18-Nov-2004 08:48:09  Warning %LINK-W-Down: 2/e40

18-Nov-2004 08:47:56  Informational %LINK-I-Up: 2/e40

39 Posts

November 18th, 2004 12:00

Thanks.  Did you have a second to look at the copy of my log?  Is that what you think is showing there?

2 Intern

 • 

812 Posts

November 18th, 2004 13:00

When a port is flapping due to physical layer issues, you will typically see these messages reported on a port multiple times repeatedly. If these are client ports, you can minimize the problems caused by flapping ports by enabling portfast (also called fastlink or edgeport) on the port while you troubleshoot the problem. This will not prevent the port from flapping, but it will allow Spanning Tree to put the port directly in a forwarding state when it transitions from a link-down state to link-up.

39 Posts

November 30th, 2004 13:00

Is STP really needed on a smallish network (less than 200 workstations)?

2 Intern

 • 

812 Posts

November 30th, 2004 13:00

The number of client workstations on the network is not a factor in determining whether STP should be used. If you have 2 or more managed switches on the network you should use STP to prevent bridging loops. If someone were to accidentally create a loop in the network without STP running on the switches, it would cause a broadcast storm that could crash the entire network.

39 Posts

November 30th, 2004 15:00

So is it ok to use RSTP with Fastlink on the client worstation links?  or will Fastlink negate the benefit of having RSTP?  I'd like to have the loop/storm protection of STP, but its STP that seems to be causing my network connection problems.

2 Intern

 • 

812 Posts

November 30th, 2004 17:00

You should enable fastlink on client ports and leave it disabled on unused or uplink ports.

Spanning Tree should not be causing the ports to rapidly change between Up/Down states. It will simply compound the problems caused by port flapping due to the amount of time it takes for the port to forward traffic when the port changes back to an Up state. If disabling Spanning Tree (or enabling fastlink) causes the port to stop flapping up/down, you should contact tech support via phone. They may need to look into this further and possibly try to duplicate the problem.

5 Posts

December 20th, 2004 19:00

We are having similar issues with 2 x 3348 & 1 x 5324

I have tried the Fast Link option, changing to Rapid STP and still have issues.

Any ideas?  On the 5324 we are using CAT 6 cables straight from the server to the switch.

see our example:

   Log Index  Log Time Severity Description   
   
  1   2147483602   20-Dec-2004 14:09:53    Warning  %STP-W-PORTSTATUS: g17: STP status Forwarding          
  2   2147483603   20-Dec-2004 14:09:30    Warning  %LINK-W-Down:  g13          
  3   2147483604   20-Dec-2004 14:09:23    Informational  %LINK-I-Up:  g17          
  4   2147483605   20-Dec-2004 14:04:21    Warning  %STP-W-PORTSTATUS: g10: STP status Forwarding          
  5   2147483606   20-Dec-2004 14:03:51    Informational  %LINK-I-Up:  g10          
  6   2147483607   20-Dec-2004 14:03:46    Warning  %LINK-W-Down:  g16          
  7   2147483608   20-Dec-2004 14:03:43    Informational  %LINK-I-Up:  g16          
  8   2147483609   20-Dec-2004 14:03:40    Warning  %LINK-W-Down:  g16          
  9   2147483610   20-Dec-2004 14:02:20    Warning  %STP-W-PORTSTATUS: g16: STP status Forwarding          
  10   2147483611   20-Dec-2004 14:01:50    Informational  %LINK-I-Up:  g16          
  11   2147483612   20-Dec-2004 14:01:48    Warning  %LINK-W-Down:  g16          
  12   2147483613   20-Dec-2004 14:01:15    Warning  %STP-W-PORTSTATUS: g16: STP status Forwarding          
  13   2147483614   20-Dec-2004 14:00:45    Informational  %LINK-I-Up:  g16          
  14   2147483615   20-Dec-2004 14:00:43    Warning  %LINK-W-Down:  g10          
  15   2147483616   20-Dec-2004 13:52:01    Warning  %STP-W-PORTSTATUS: g10: STP status Forwarding          
  16   2147483617   20-Dec-2004 13:51:31    Informational  %LINK-I-Up:  g10          
  17   2147483618   20-Dec-2004 13:51:29    Warning  %LINK-W-Down:  g10          
  18   2147483619   20-Dec-2004 13:51:09    Warning  %STP-W-PORTSTATUS: g10: STP status Forwarding          
  19   2147483620   20-Dec-2004 13:50:39    Informational  %LINK-I-Up:  g10          
  20   2147483621   20-Dec-2004 13:50:34    Warning  %LINK-W-Down:  g10          
  21   2147483622   20-Dec-2004 13:33:09    Warning  %STP-W-PORTSTATUS: g13: STP status Forwarding          
  22   2147483623   20-Dec-2004 13:32:39    Informational  %LINK-I-Up:  g13          
  23   2147483624   20-Dec-2004 13:32:37    Warning  %LINK-W-Down:  g13          
  24   2147483625   20-Dec-2004 13:32:17    Warning  %STP-W-PORTSTATUS: g13: STP status Forwarding          
  25   2147483626   20-Dec-2004 13:31:47    Informational  %LINK-I-Up:  g13          
  26   2147483627   20-Dec-2004 13:31:46    Warning  %LINK-W-Down:  g13          
  27   2147483628   20-Dec-2004 13:31:35    Warning  %STP-W-PORTSTATUS: g13: STP status Forwarding          
  28   2147483629   20-Dec-2004 13:31:05    Informational  %LINK-I-Up:  g13          
  29   2147483630   20-Dec-2004 13:30:10    Warning  %LINK-W-Down:  g13          
  30   2147483631   20-Dec-2004 13:27:42    Warning  %STP-W-PORTSTATUS: g13: STP status Forwarding          
  31   2147483632   20-Dec-2004 13:27:12    Informational  %LINK-I-Up:  g13          
  32   2147483633   20-Dec-2004 13:27:11    Warning  %LINK-W-Down:  g13          
  33   2147483634   20-Dec-2004 13:25:03    Warning  %STP-W-PORTSTATUS: g13: STP status Forwarding          
  34   2147483635   20-Dec-2004 13:24:33    Informational  %LINK-I-Up:  g13          
  35   2147483636   20-Dec-2004 12:50:43    Warning  %LINK-W-Down:  g11          
  36   2147483637   20-Dec-2004 12:49:36    Warning  %LINK-W-Down:  g12          
  37   2147483638   20-Dec-2004 12:09:41    Warning  %STP-W-PORTSTATUS: g11: STP status Forwarding          
  38   2147483639   20-Dec-2004 12:09:11    Informational  %LINK-I-Up:  g11          
  39   2147483640   20-Dec-2004 12:06:53    Warning  %STP-W-PORTSTATUS: g12: STP status Forwarding          
  40   2147483641   20-Dec-2004 12:06:23    Informational  %LINK-I-Up:  g12          
  41   2147483642   20-Dec-2004 12:03:09    Warning  %STP-W-PORTSTATUS: g10: STP status Forwarding          
  42   2147483643   20-Dec-2004 12:02:53    Warning  %STP-W-PORTSTATUS: g9: STP status Forwarding          
  43   2147483644   20-Dec-2004 12:02:39    Informational  %LINK-I-Up:  g10          
  44   2147483645   20-Dec-2004 12:02:30    Warning  %STP-W-PORTSTATUS: g8: STP status Forwarding          
  45   2147483646   20-Dec-2004 12:02:23    Informational  %LINK-I-Up:  g9          
  46   2147483647   20-Dec-2004 12:02:00    Informational  %LINK-I-Up:  g8   

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