A structured approach avoids looking for the way in when the VLAN does not already reach it.
Steps.
- List VLANs. – Note those who have to cross the city.
- Compare the two ports. — Check mode,,,, VLAN and,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,, ,, ,,,, ,
- ObserverMac. — Check the relevant VLAN learning.
- Test gradually. — Use a VLAN known as a reference.
Key takeaways
- Both ends must be consistent.
- A single functional VLAN does not prove that the complete trunk is correct.