Cisco Support Community
cancel
Showing results for 
Search instead for 
Did you mean: 
Announcements

Welcome to Cisco Support Community. We would love to have your feedback.

For an introduction to the new site, click here. If you'd prefer to explore, try our test area to get started. And see here for current known issues.

New Member

MPLS & Vlans - Basic question

We have 2 types of connection into our MPLS network.

One is via ethernet & the other is via ADSL which enters the MPLS network at our ISP's exchange.

Would I be right in assuming that any vlan tags on the ethernet connection will be intact entering and leaving the MPLS network whereas the ADSL connected tags will be stripped prior to entering the MPLS network?

3 REPLIES
Silver

MPLS & Vlans - Basic question

Ethernet tags are stripped on a non-MPLS IP network. The same should hold true for MPLS based networks. There is no need to carry VLAN tag end-to-end unless you are doing EoMPLS.

HTH.

New Member

MPLS & Vlans - Basic question

Your topology is not very clear to me, however the only way that vlans may not be stripped is if you have a trunk port or using QinQ. I doubt your adsl link sends out tagged frames however. You can verify for sure by taking a packet trace

Hope this helps

Mark

MPLS & Vlans - Basic question

Hi Louis,

you can't generally state that. It really depends on the nature of the links in the middle and the policy for your customer to go out via the ISP. If you devliver (for example) native IP packets at the ISP's exchange there is no MPLS involvement in it. If instead you are delivering an L2VPN + Interworking IP i would assume that both ETH VLAN and ATM would be stripped off at the exchange. Much depends from the overall design. A couple more of different cases would be L3VPN on an Inter-AS design.

Alessio

730
Views
0
Helpful
3
Replies