Analyzing Spanning Tree Protocols
All of us have worked with, or at least heard about, STP (Spanning Tree Protocol). The reason I call this recipe Analyzing Spanning Tree Protocols is because there are three major versions of it as follows:
Spanning Tree Protocol (STP): This is an IEEE 802.1D standard from 1998 called 802.1D-1998
Rapid Spanning Tree Protocol (RSTP): This is an IEEE 802.1W standard from 2001, later added to 802.1D, called 802.1D-2004
Multiple Spanning Tree (MST): This was originally defined in IEEE 802.1S and later merged into IEEE 802.1Q
There are also some proprietary versions from Cisco and other vendors. In this recipe we will focus on the standard versions, and learn how to troubleshoot problems that might occur during STP/RSTP/MST operations.
Getting ready
The best way to find out STP problems is to log in to the LAN switches and use the vendor's commands (for example, Cisco IOS or Juniper JUNOS CLI) to find and fix the problem. If you have properly configured SNMP on...
