Tek-Tips is the largest IT community on the Internet today!

Members share and learn making Tek-Tips Forums the best source of peer-reviewed technical information on the Internet!

  • Congratulations strongm on being selected by the Tek-Tips community for having the most helpful posts in the forums last week. Way to Go!

4503 vlan does not come up

Status
Not open for further replies.

wilson2468

Technical User
Jun 2, 2006
84
US
I am trying to trunk 3com switches to Cisco 4503 switches and I have tried all differnet scenarios.

I cannot get the SVI interface to come up.

My question is:

Is the trunk interface (being a member of all vlans) enough to get the vlan interface to come up when the link is connected and the Gigabit interface is up on the Cisco?

If not, what do you do when the only port in the vlan is the trunk port on the core switch?
 
As long as you have a physical connection and the link is actually trunking like it should the SVI should come up . If the trunk is not actually working on both ends then no it won't come up .
 
If your trunking between two different brand (Cisco & 3Com), pay close attention to proprietary technology. For example the default trunking encapsulation on the Cisco switch is their proprietary ISL. The 3com most likely uses the industry standard. Do some research and search this site, I’m sure it’s been addressed in previous posts.
 
Ru55el is explaining correctly:-

Cisco proprietary is ISL (dont use this)

Use 802.1q trunking (will be called dot1q in the IOS CLI)

Also, make sure both ends are configured Identically.....

 
Status
Not open for further replies.

Part and Inventory Search

Sponsor

Back
Top