DTP modes on Cisco Catalyst Switches


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 DTP mode is “dynamic auto”. Key behaviours: Dynamic ... Read More »

How to Use Virtual PC Simulator in GNS3


One or more PCs are needed to test some features, like VLANs, HSRP,… To make this possible with GNS3, I use what is called Virtual PC Simulator, or VPCS. Download Virtual PC Simulator You can download Virtual PC Simulator for free on the ... Read More »

BGP Traceoptions on Juniper Routers


#set protocols bgp traceoptions file bgp #set protocols bgp traceptions flag update detail #set protocols bgp traceptions flag keepalive detail #set protocols bgp traceptions flag open detailNow in normal operation, we should only see keepalives: Then I issued a clear ... Read More »

Adsense black background: