Wassim

In this short port we explore the possible DTP modes and configure them on a Catalyst switch. We also learn what the outcome would be if we combine them. When configuring the Dynamic Trunking Protocol, Cisco recommends to set trunking as static. But here is the behaviour if we don’t set it to “switchport mode trunk”. For Catalyst 2960 and Catalyst 3560, I found that the default Dynamic Trunking Protocol mode is “dynamic auto”. Key behaviours: Dynamic auto+ dynamic auto = access dynamic auto+ access/trunk = access/trunk Dynamic desirable + access = access Dynamic desirable + else = trunk Default modes Here are a couple of outputs that reveal the default Dynamic Trunking Protocol modes, on Catalyst 2960 and Catalyst 3560: on Catalyst 2960 on a 3560 A combination of the above I’m going to set different DTP modes on both ends of the link, and see the behaviour of DTP on Catalyst switches. I have SW1 and SW0. Dynamic desirable + Access –> Access W...

In this lab, I learned the following: configuring a HSRP group on physical interfaces, testing how a PC can reach a remote subnet through a redundant gateway, by configuring its default gateway as the HSRP virtual address, testing how the second router becomes Active, testing interface tracking. For interface tracking, at first, I thought there was a problem with the lab. Topology: configure interface tracking and a decrement value: When I shut down ser0/0 on R2, I expected R2 to become Standby router. But reality bites: Then I checked on R3. R3 is still Standby, not Active ! So what’s wrong? Here’s what Cisco says: How Object Tracking Affects the Priority of an HSRP Router The priority of a device can change dynamically if it has been configured for object tracking and the object that is being tracked goes down. The tracking process periodically polls the tracked objects and notes any change of value. The changes in the tracked object are communicated to HSRP, either immedi...