PublicLAN
ExchangeNET
Ultra 1G
FibreLINK
PrivateLAN
CityBRIDGE
SiteNET
Harmony
CaféNET
WatchNETWhy is my link flapping regularly: Spanning Tree
CityLink implements a BPDU guard on all ports. For an in depth discussion of this see http://news.clnz.net/2008/11/19#November-Faults .
If you connect equipment to the CityLink network that is sending Spanning Tree BPDU's then it's likely that the network will react by disabling your port briefly. After a short delay the network will re-enable the port. If your equipment continues to send BPDU's then the port will be disabled again. The port will appear to flap approximately once per minute. The remedy is to disable Spanning Tree on the port facing CityLink.
See "Useful Config Statements" below for help preventing a switch from sending Spanning Tree BPDU's.
If you require Spanning Tree (for example, you connect to CityLink in multiple locations and you rely on Spanning Tree to prevent loops) or you are unable to disable Spanning Tree please contact CityLink to discuss (tech@citylink.co.nz).
