L2 between seperate VTP domains

Unanswered Question
May 28th, 2007
User Badges:


I am trying to configure our 6506 to communicate with a separate network. Currently we use STP MST and have a vtp server configured. I just added a 3550, but it needs to be on a different vtp domain. My real problem is that my current network has a vlan with the network assigned to it. The new network needs to use a network. I can't create a layer 3 interface because the network is assigned to the VLAN. Can this be set up via L2 and non-routed or private VLAN's. Does anyone have any experience with anything like this?

Thanks in advance.

  • 1
  • 2
  • 3
  • 4
  • 5
Overall Rating: 0 (0 ratings)
scottmac Mon, 05/28/2007 - 08:36
User Badges:
  • Green, 3000 points or more

No, I don't think you can.

At layer two, everything is Ethernet (MAC) ... there's no manipulation of an IP (or any other network-level) address.

Best case that I can think of would be a NAT, but that's still a layer three+ issue.

IMHO, you'll need to do some re-addressing at one place or another, in the meantime, maybe a router using SECONDARY addressing on the ambiguous interface. BEcareful though, SECONDARY addressing can cause some "issues" with some routing protocols (like spilt horizon problems).

Good Luck


johnsonk1024 Mon, 05/28/2007 - 08:44
User Badges:

I have a router I can use, but I would like to keep the latency as low as possible because the data will primarily be streaming medical images.

Would a bridge interface on the router (2821) help alleviate latency or should I set this up as standard interfaces? BTW, I have two gig fiber interfaces.

johnsonk1024 Mon, 05/28/2007 - 09:36
User Badges:

Would it not be possible to set this up with trunk ports on each side and then use Switchport trunk allowed vlan xxx-xxxx to achieve the same effect as a routed link?


This Discussion