Just got a comment on my DTP post. I had made a comment about DTP still running even when a switch port was configured in static access mode. To be honest, I hadn’t tested this in my lab. I just read it in the Cisco cert guide. A reader made a comment about that not being true on the 3560 MLS so I took a closer look at it on the 2960s and 3750s tonight that I have in my lab. Sure enough, if you turn up a port that’s configured for ‘switchport mode access’ DTP doesn’t talk. In fact, it tells you that it isn’t going to talk…
*Mar 1 00:10:24.926: %LINK-3-UPDOWN: Interface FastEthernet1/0/1, changed state to up
*Mar 1 00:10:25.580: DTP-queue:Fa1/0/1:Not queuing DTP packet: DTP not enabled ../dyntrk/dyntrk_process.c:1362
*Mar 1 00:10:25.932: %LINEPROTO-5-UPDOWN: Line protocol on Interface FastEthernet1/0/1, changed state to up
*Mar 1 00:10:26.587: DTP-queue:Fa1/0/1:Not queuing DTP packet: DTP not enabled ../dyntrk/dyntrk_process.c:1362
At any rate, it’s great to see that people are reading my blog and that they are catching my mistakes. Can’t think of a better way to share and learn at the same time. Keep the comments and corrections coming!