09-19-2017 05:11 AM - edited 03-01-2019 02:03 PM
Heey, all
As an ISP provider, We are trying to connect Multiple customer sites via our Mpls core.
our plan to give each customer site a different vlan ( c-vlan) and then translated to S-vlan to transport the frames through our network. we know about vlan map as we map each customer vlan to s-vlan but this is Symmetrica operation which I read on cisco article
(On an interface configured for VLAN mapping, the specified C-VLAN packets are mapped to the specified S-VLAN when they enter the port. Symmetrical mapping back to the customer C-VLAN occurs when packets exit the port.)
But this won't work in our design because we want to assign a different vlan at each customer site.
I read on junpier articles they have a technology vlan swapping which swap c-vlan with new s-vlan by discarding the c-vlan tag and adding a new s-vlan tag.
This is written in juniper article:
(VLAN translation (swapping) replaces an incoming C-VLAN tag with an S-VLAN tag instead of adding an additional tag. The C-VLAN tag is therefore lost,)
Is there any similar technology in cisco?
Thanks
Solved! Go to Solution.
09-20-2017 04:40 PM
Hi
On your PE1, the config should looks like:
interface g0/1
switchport trunk encapsulation dot1q
switchport trunk allowed vlan none
switchport mode trunk
service instance 1 ethernet
encapsulation dot1q 2150
rewrite ingress tag pop 1 symmetric
xconnect x.x.x.x 1 encapsulation mpls
On PE2, it will be:
interface g0/1
switchport trunk encapsulation dot1q
switchport trunk allowed vlan none
switchport mode trunk
service instance 1 ethernet
encapsulation dot1q 123
rewrite ingress tag pop 1 symmetric
xconnect x.x.x.x 1 encapsulation mpls
The frame arrives to your PE1 tagged and when sending out through xconnect, the tag will be removed. A new tag will be added on PE2 with the vlan configured under the service instance. This behaviour of tag removing is done by rewrite ingress tag pop 1 symmetric
Does that help?
I'm sorry, I was planning to connect on 1 of my routers to make some wireshark and show the different frames but didn't had time for that.
Thanks
09-19-2017 08:12 PM
Hi
Before talking about configurations, did you tried with EVC (service instance configuration)?
09-20-2017 02:19 AM
09-20-2017 04:40 PM
Hi
On your PE1, the config should looks like:
interface g0/1
switchport trunk encapsulation dot1q
switchport trunk allowed vlan none
switchport mode trunk
service instance 1 ethernet
encapsulation dot1q 2150
rewrite ingress tag pop 1 symmetric
xconnect x.x.x.x 1 encapsulation mpls
On PE2, it will be:
interface g0/1
switchport trunk encapsulation dot1q
switchport trunk allowed vlan none
switchport mode trunk
service instance 1 ethernet
encapsulation dot1q 123
rewrite ingress tag pop 1 symmetric
xconnect x.x.x.x 1 encapsulation mpls
The frame arrives to your PE1 tagged and when sending out through xconnect, the tag will be removed. A new tag will be added on PE2 with the vlan configured under the service instance. This behaviour of tag removing is done by rewrite ingress tag pop 1 symmetric
Does that help?
I'm sorry, I was planning to connect on 1 of my routers to make some wireshark and show the different frames but didn't had time for that.
Thanks
09-21-2017 03:29 AM
It really seems to work in this kind of logic. I wish I could practice this lab on simulator but no hope since this commands are not avaiable inn GNS3.
Thanks,,
09-21-2017 12:17 PM
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