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Trunk Configuration for Cisco 3550 & EMI


I have one 3550-48-EMI switch and two 2945G-48 switches and they're connected as cascade configuration without redundant loop.

3550 has four VLANs and I'd like to allocate one VLAN for client computers only, and I also like to use two 2945G-48 switches for this VLAN as well.

It looks something like this....

+----------------------------------------+ VLAN 70, VLAN 90, VLAN 110

| Cisco 3550 00 00 |

+-------------------------------------/---+ VLAN100 (Client Lan)



| Cisco 2945G 00 00 |

+-------------------------------------/---+ VLAN100 (Client Lan)



| Cisco 2945G 00 00 | VLAN100 (Client Lan)


Can I just configure gigabit ethernet port 0/2 of 3550 as follow?

or do I have to configure each switches with the same VLAN informations?

interface GigabitEthernet0/2

switchport access vlan 100

switchport trunk encapsulation dot1q

switchport trunk native vlan 100

switchport mode trunk

no ip address

I know this configuration is wrong, but could you please tell me what is wrong with this configuration and what is needed to be done to resolve this issues?

Thank you very much for your help in advance.

- Jon

  • Other Network Infrastructure Subjects
Cisco Employee

Re: Trunk Configuration for Cisco 3550 & EMI

if the 2950's have VLAN 100 only, you do not have to trunk. The only configuration you'll need on the interfaces connecting two switches is

interface GigabitEthernet0/x

switchport access vlan 100

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