CCNP TSHOOT CHAPTER 2 (TRUNK)

CCNP TSHOOT CHAPTER 2 (TRUNK)
2. What are the commands to on/off DTP ?
3. List different options to trunk negotiation ?
4. What are different check-list for Trunk troubleshooting ?
Solution:
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2. What are the commands to on/off DTP ?
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switchport mode access > will off DTP
switchport mode trunk  > will on DTP
switchport nonegotiate

Puts the LAN port into permanent trunking mode but prevents
the port from generating DTP frames. You must configure the
neighboring port manually as a trunk port to establish a
trunk link.

3. List different options to trunk negotiation ?
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Mode1                    Mode2    Trunk
Trunk                      Acess     No
Trunk                     Trunk      Yes
Dynamic desirable  Trunk      Yes
Dynamic auto         D. D       Yes

4. What are different check-list for Trunk troubleshooting ?
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a. check encapsulation mismatch : ISL vs 802.1Q
b . Native vlan mismatch (check untagged vlan)
c . Any layer 1 issue
d . DTP misconfig (auto -- auto ) will not form trunk
e . Check VTP issue ( VTP ver 1 ---- VTP ver 2) will not form trunk.
f . # sh inter trunk
# sh int fa0/2 switchport | ex private|unknown