I always maintained "swi mode access + swi noneg" on grounds of my own paranoia. However, I learned to control that urge, as "swi mode access" indeed disables DTP, as proven many times by so many people and their debugs :-)
-- Marko Milivojevic - CCIE #18427 Senior Technical Instructor - IPexpert FREE CCIE training: http://bit.ly/vLecture Mailto: [email protected] Telephone: +1.810.326.1444 Web: http://www.ipexpert.com/ On Thu, Jan 20, 2011 at 14:29, Nicolas MICHEL <[email protected]> wrote: > ok Switchport mode access + Switchport mode access show that Trunking is > not negotiated ... > But I have also read on Ruhann's note that when they ask to config a static > access port , Switchport nonegotiate is needed ... > > Marko, Tyson can you please confirm ? > > > Thanks Yap for your time. > > > > > > 2011/1/18 Yap Chin Hoong - <[email protected]> > >> >> Hi Nicholas, >> I have tested that 'switchport mode access' + 'switchport nonegotiate' >> is equivalent to 'switchport mode access' only. Switch ports configured with >> both combinations of commands do not send DTP packets, as proven using the >> 'debug dtp packets' privileged command on both Catalyst 2950 and Catalyst >> 3560 series switches. >> Below are some captures during my DTP studies. Thanks. >> >> TOS - Trunk Operational Status >> >> TAS - Trunk Administrative Status >> >> TNS - Trunk Negotiated Status >> >> TOT - Trunk Operational Trunking Encapsulation >> >> TAT - Trunk Administrative Trunking Encapsulation >> >> TNT - Trunk Negotiated Trunking Encapsulation >> >> >> >> >> ================================================================================ >> >> C3560 >> dynamic auto <> C3560 dynamic auto >> >> C3560#sh int fa0/1 >> switchport | in Administrative Mode|Administrative Trunking|Negotiation >> >> Administrative >> Mode: dynamic auto >> >> Administrative >> Trunking Encapsulation: negotiate >> >> Negotiation >> of Trunking: On >> >> C3560# >> >> C3560#sh dtp int fa0/1 | >> in TOS|TOT >> >> TOS/TAS/TNS: >> ACCESS/AUTO/ACCESS >> >> TOT/TAT/TNT: >> NATIVE/NEGOTIATE/NATIVE >> >> 0 bad TLVs, 0 bad TAS, 0 bad TAT, 0 bad >> TOT, 0 other >> >> C3560# >> >> >> ================================================================================ >> >> C3560 >> dynamic auto <> C2950 dynamic desirable >> >> C3560#sh int fa0/1 >> switchport | in Administrative Mode|Administrative Trunking|Negotiation >> >> Administrative >> Mode: dynamic auto >> >> Administrative >> Trunking Encapsulation: negotiate >> >> Negotiation >> of Trunking: On >> >> C3560# >> >> C3560#sh dtp int fa0/1 | >> in TOS|TOT >> >> TOS/TAS/TNS: TRUNK/AUTO/TRUNK >> >> TOT/TAT/TNT: 802.1Q/NEGOTIATE/802.1Q >> >> 0 bad TLVs, 0 bad TAS, 0 bad TAT, 0 bad >> TOT, 0 other >> >> C3560# >> >> >> ================================================================================ >> >> C3560 >> dynamic auto <> Cisco 2600 >> >> C3560#sh int fa0/1 >> switchport | in Administrative Mode|Administrative Trunking|Negotiation >> >> Administrative >> Mode: dynamic auto >> >> Administrative >> Trunking Encapsulation: negotiate >> >> Negotiation >> of Trunking: On >> >> C3560# >> >> C3560#sh dtp int fa0/1 | >> in TOS|TOT >> >> TOS/TAS/TNS: >> ACCESS/AUTO/ACCESS >> >> TOT/TAT/TNT: >> NATIVE/NEGOTIATE/NATIVE >> >> 0 bad TLVs, 0 bad TAS, 0 bad TAT, 0 bad >> TOT, 0 other >> >> C3560# >> >> >> ================================================================================ >> >> C3560 >> dynamic desirable <> C3560 dynamic auto >> >> C3560#sh int fa0/1 >> switchport | in Administrative Mode|Administrative Trunking|Negotiation >> >> Administrative >> Mode: dynamic desirable >> >> Administrative >> Trunking Encapsulation: negotiate >> >> Negotiation >> of Trunking: On >> >> C3560# >> >> C3560#sh dtp int fa0/1 | >> in TOS|TOT >> >> TOS/TAS/TNS: >> TRUNK/DESIRABLE/TRUNK >> >> TOT/TAT/TNT: ISL/NEGOTIATE/ISL >> >> 0 bad TLVs, 0 bad TAS, 0 bad TAT, 0 bad >> TOT, 0 other >> >> C3560# >> >> >> ================================================================================ >> >> C3560 >> switchport trunk encapsulation dot1q, switchport mode trunk <> C3560 >> dynamic auto >> >> C3560#sh int fa0/1 >> switchport | in Administrative Mode|Administrative Trunking|Negotiation >> >> Administrative >> Mode: trunk >> >> Administrative >> Trunking Encapsulation: dot1q >> >> Negotiation >> of Trunking: On >> >> C3560# >> >> C3560#sh dtp int fa0/1 | >> in TOS|TOT >> >> TOS/TAS/TNS: TRUNK/ON/TRUNK >> >> TOT/TAT/TNT: >> 802.1Q/802.1Q/802.1Q >> >> 0 bad TLVs, 0 bad TAS, 0 bad TAT, 0 bad >> TOT, 0 other >> >> C3560# >> >> >> ================================================================================ >> >> C3560 >> switchport trunk encapsulation dot1q, switchport mode trunk, switchport >> nonegotiate <> C3560 dynamic auto >> >> C3560#sh int fa0/1 >> switchport | in Administrative Mode|Administrative Trunking|Negotiation >> >> Administrative >> Mode: trunk >> >> Administrative >> Trunking Encapsulation: dot1q >> >> Negotiation >> of Trunking: Off >> >> C3560# >> >> C3560#sh dtp int fa0/1 | >> in TOS|TOT >> >> TOS/TAS/TNS: >> TRUNK/NONEGOTIATE/TRUNK >> >> TOT/TAT/TNT: >> 802.1Q/802.1Q/802.1Q >> >> 0 bad TLVs, 0 bad TAS, 0 bad TAT, 0 bad >> TOT, 0 other >> >> C3560# >> >> >> ================================================================================ >> >> C3560 >> switchport mode access <> C3560 switchport mode access >> >> C3560#sh int fa0/1 >> switchport | in Administrative Mode|Administrative Trunking|Negotiation >> >> Administrative >> Mode: static access >> >> Administrative >> Trunking Encapsulation: negotiate >> >> Negotiation >> of Trunking: Off >> >> C3560# >> >> C3560#sh dtp int fa0/1 | in >> TOS|TOT >> >> TOS/TAS/TNS: ACCESS/OFF/ACCESS >> >> TOT/TAT/TNT: >> UNKNOWN/NEGOTIATE/UNKNOWN >> >> 0 bad TLVs, 0 bad TAS, 0 bad TAT, 0 bad >> TOT, 0 other >> >> C3560# >> >> >> >> regards, >> YapCH >> http://itcertguides.blogspot.com/ >> >> > Message: 3 >> > Date: Tue, 18 Jan 2011 13:15:49 +0100 >> > From: Nicolas MICHEL >> > To: OSL Routing and Switching >> > Subject: [OSL | CCIE_RS] DTP for Dummies >> > Message-ID: >> > >> > Content-Type: text/plain; charset=ISO-8859-1 >> > >> > Hey there. >> > >> > >> > DTP is such an easy protocol . There are only few commands to enable or >> > disable it. >> > I've been reading so much crap about this since my CCNA on cisco forums >> that >> > I d like to discuss about it with you guys. >> > >> > >> > Some people says that DTP can only be shutted with the command switchport >> > nonegotiage. >> > Some people says that DTP can only be shutted with the command switchport >> > mode access .... >> > >> > >> > I disagree and I noticed that switchport mode access did indeed shut the >> DTP >> > process .... >> > >> > Rack1SW1(config-if)#do sh int fa0/21 sw >> > Name: Fa0/21 >> > Switchport: Enabled >> > Administrative Mode: static access >> > Operational Mode: static access >> > Administrative Trunking Encapsulation: dot1q >> > Operational Trunking Encapsulation: native >> > *Negotiation of Trunking: Off* >> > Access Mode VLAN: 1 (default) >> > Trunking Native Mode VLAN: 146 (VLAN0146) >> > Administrative Native VLAN tagging: enabled >> > Voice VLAN: none >> > Administrative private-vlan host-association: none >> > Administrative private-vlan mapping: none >> > Administrative private-vlan trunk native VLAN: none >> > Administrative private-vlan trunk Native VLAN tagging: enabled >> > Administrative private-vlan trunk encapsulation: dot1q >> > Administrative private-vlan trunk normal VLANs: none >> > Administrative private-vlan trunk associations: none >> > Administrative private-vlan trunk mappings: none >> > Operational private-vlan: none >> > Trunking VLANs Enabled: ALL >> > Pruning VLANs Enabled: 2-1001 >> > Capture Mode Disabled >> > >> > >> > >> > So what do you guys think about this newbie question ? :) >> > >> > >> > -- >> > Nicolas MICHEL >> > Ingenieur R?seaux et Securit? (CCNA/CCNP) >> > >> >> >> >> _______________________________________________ >> For more information regarding industry leading CCIE Lab training, please >> visit www.ipexpert.com >> > > > > -- > Nicolas MICHEL > Ingenieur Réseaux et Securité (CCNA/CCNP) > _______________________________________________ > For more information regarding industry leading CCIE Lab training, please > visit www.ipexpert.com > _______________________________________________ For more information regarding industry leading CCIE Lab training, please visit www.ipexpert.com
