DBTN

The vPC Peer-Switch feature allows a pair of vPC peer devices to appear as a single logical Spanning Tree Protocol root. With vPC Peer-Switch enabled downstream devices see both switches as the STP root. Without vPC Peer-Switch enabled downstream devices still have to funnel Layer 2 traffic via the STP root using the traditional STP traffic flow. The main advantage of vPC peer-swtich is the improvement in term of convergence time during vPC primary peer device failure/recovery.    Without vPC peer-switch feature vPC primary peer device failure and recovery can create around 3 seconds of traffic disruption  With vPC peer-switch traffic disruption is lowered to sub-second value  This is since peer device down an up events do not generate any Rapid Spanning Tree Protocol Sync behavior, because, there is no logical change in the L2 topology. Things to keep in mind: It is a Cisco recommended best practice to activate vPC peer-switch within a vPC environment. vPC peer-swit...

 Quick reference for which Fiber Channel port types can be used for are likely to show up on 350-601 and 300-625 Cisco Exams: • E Port • F Port • NP Port • TE Port • SD Port • Auto Mode E Port In expansion port (E port) mode, an interface functions as a fabric expansion port.  This port can be connected to another E port to create an inter-switch link between two switches. E ports carry frames between switches for configuration and fabric management.  They serve as a conduit between switches for frames destined for remote N ports.  An E port connected to another switch can also be configured to form a port channel.  F Port In fabric port (F port) mode, an interface functions as a fabric port.  This port can be connected to a peripheral device (host or disk) operating as an N port.  An F port can be attached to only one N port. NP Ports An NP port is a port on a device that is in NPV mode and connected to the core switch via an F port.  NP ports fu...

Once upon a time I managed to get myself locked out of a device entirely. Traffic was still flowing, monitoring was still fine, but I could not get into a command line for a Core Switch. This is the method I used to add a new privileged user to the configuration via SNMP, so I could get back into the device.  Things you'll need Device with SNMP RW (Read/Write) and not just RO (Read-Only) Computer with the ability to use snmpset Linux: Free Software found here. Windows: Free Software found here. Computer with the ability to be a tftp server Linux: Free Software found here. Windows: Free software found here. Requirement #1 Device with SNMP RW :  The following is from the CLI of my Cisco 881W Switch  I have a RW community string of "DBTN"  Requirement #2   Computer with snmpset : The following is from my Raspberry Pi.  Requirement #3   Computer with the ability to be a tftp server : The following is...