05-10-2024 02:05 PM
Hi All,
I am doing some testing for a migration from a 7604 MPLS PE with handoffs to a 7604 acting as an edge router.
Each circuit on the PE router is just an untagged attachment circuit like this:
interface GigabitEthernet2/8
description MPLS Attachment Circuit for Customer
no ip address
no keepalive
xconnect <remote IP> <vc ID> encapsulation mpls
The Handoff on PE attachment corresponds to a physical link between the MPLS router and the edge router:
They are co-located in the same data center.
The handoff on the edge 7600 looks like this for the example customer above (it is just an access port into a VLAN).
interface GigabitEthernet4/8
switchport
switchport mode access
switchport access vlan <vlan #>
end
The 'Edge' 7600 has interface VLANs which are the gateways for their respective subnets.
There is a static route directed to a directly connected route for it upstream.
I wanted to get some feedback on my process:
I wanted to see about moving off of the transport/PE MPLS router first onto a new router.
This would uplink to a trunk port on the current edge 7600 router with a different MPLS PE router that is running IOS XR.
I plan to use subints with l2transport to differentiate traffic by VLANs that are on the trunk and then using an l2vpn bridge group I can have different pw-id pointed back through this one handoff to the edge router and consolidate them on to a single handoff versus a handoff-per circuit.
How does that sound?
The next issue I would need to tackle once I get the transport MPLS router moved is the issue of the int VLANs/gateway residing on the 7600.
What ideas do you have about a floating gateway to help migrate that?
05-13-2024 01:03 AM - edited 05-13-2024 01:04 AM
I didn't understand the exact topology, but be careful with the bridge-domain/bridge-group usage. It requires "rewrite ingress tag pop 1 symmetric" to be configured under l2transport interface.
So at some point you might won't be able to distinguish traffic from different vlans (as vlan tags are popped before processing by the bridge-group) and you have to use hand-off per circuit.
Best Regards,
P.
05-13-2024 06:21 AM
I will explain a bit more detail of how it is currently set up:
Customer CPE:
Untagged switch (but capable of management). Some customer locations have a management VLAN, but the data VLAN is untagged still. The trunk from the customer CPE uplinks to a remote MPLS PE that has an l2vpn that points back to the transport 7604 we are wanting to get rid of.
[Customer CPE] [Remote PE]
[1] [2] [3] [4 - trunk] <----------> [Service instance 1 - encapuslation untagged -> xconnect to core transport 7600]
[Service instance 2 - encapsulation dot1q <management VLAN> rewrite ingress pop 1 symmetric to a local BDI for management]
[Transport 7600 - one we are wanting to remove]
[no service instance, just vanilla xconnect, example below]
description MPLS Attachment Circuit for Customer
no ip address
no keepalive
xconnect <remote IP> <vc ID> encapsulation mpls
[Edge Router - other 7604 which is slated for removal]
access ports that are one-to-one mapped from ports from the other 7604 to specify which VLAN untagged traffic needs to go to:
interface GigabitEthernet4/8
switchport
switchport mode access
switchport access vlan <vlan #>
end
05-13-2024 08:23 AM
You can use backup pseudowire on the remote PE, which will be terminated on the new IOS XR router.
xconnect <remote IP> <vc ID> encapsulation mpls
backup peer <remote IP> <vc ID>
On the new IOS XR router you do not need to use bridge-domain/bridge-group, just p2p xconnect
interface TenGigE0/0/2/0.17 l2transport
description towards Edge Router
encapsulation dot1q 17
rewrite ingress tag pop 1 symmetric
!
l2vpn
xconnect group <>
p2p <>
interface TenGigE0/0/2/0.17
neighbor ipv4 <remote IP> pw-id <vc ID>
You can then switchover traffic from active to backup pseudowire and remove the Transport 7600.
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