I started freestyle labbing to review some topics, and found some interesting behaviors along the way I wanted to make note of here, so this will be more of a troubleshooting / behaviors demonstration than a configuration of any particular topic. The topic I went with here is creating VLANs local to their respective switches, … Continue reading SWITCH Lab – Manual VLAN Pruning on Trunk interfaces, STP / EtherChannel behaviors, SWITCH and TSHOOT lab!
The above Topology is configured waaaay toward the bottom of the post, there is a lot of ground to cover in terms of the evolution of STP, and clarifying some differences in flavors. I have spent days researching Cisco documentation / Blogs / Discussions / Training material to cross reference MST information, as this is … Continue reading STP – Multiple Spanning-Tree (MST), CST, PVST vs PVST+ reviewed, illustrated, configured and verified on the lab!
The following will be used for labbing RSTP, with a lot going on there, so lets hit it! Fundamentals of 802.1w RSTP, similarities and difference from 802.1d STP RSTP is Rapid Spanning-Tree Protocol IEEE 802.1w, the evolution of 802.1 PVST STP that we have been labbing (default STP is PVST), RSTP is also … Continue reading RSTP – Fundamentals, Port States and Link Types explained IN DEPTH, configured and verified on the lab!
The above Topology represents a failure on a Fiber Optic Transmit / Receive cable pair on one cable, on one end of the link, which would leave the link up and Unidirectional. Here is an example of the SFP Transceiver and Fiber cable connecting to a switch: Source : This Cisco.com 2960x Fiber Stacking article … Continue reading STP – Fiber Cabling, Loop Guard and UDLD DEEP DIVE, and important notes for exam day!
In this Topology everything is default, so SW1 has one the Root Bridge election with the lowest MAC Address as the tie breaker, and all port states were dynamically calculated. There is a lot to hit on these multiple STP topics, so, without further ado! First a quick peek at a great verification command … Continue reading STP – Root Guard, BPDU Guard, and BPDU Filter mechanics, behaviors, and verification labbed!
Note that SW4 is the 3560 that survived the purge of old switches in my lab, and its interfaces do show as Fa0/X instead of Fa1/0/X, so be aware of that with output. Spanning-Tree Portfast STP Portfast configuration allows an STP Port to go straight from Blocking Mode to Forwarding mode, skipping the … Continue reading STP – Portfast, Direct vs Indirect Link failure illustrated, Uplinkfast, and Backbonefast labbed!
Above is a design issue that may be present on exam day or on the job, the issue being that as indicated in the top right corner there are 4 VLANs configured on both sides of the Trunks, but SW2 has interface Fa1/0/2 set to blocking - So only one link is being used for … Continue reading STP – Interface Cost config, VLAN load balancing with PVST and Port Priority, and verification commands labbed!