EVPN can be used in MPLS networks where provider edge (PE) routers are interconnected through any type of MPLS tunnel, including RSVP-TE, LDP, BGP, Segment Routing IS-IS, or Segment Routing OSPF. As with VPRN services, the tunnel selection for a VPLS service (with BGP-EVPN MPLS enabled) is based on the auto-bind-tunnel command.
The EVPN-MPLS VPLS service uses a regular VPLS service where EVPN-MPLS ‟bindings” can coexist with SAPs. The following is a sample configuration output that shows a VPLS service with EVPN-MPLS.
*A:PE-1>config>service>vpls# info
----------------------------------------------
description "evpn-mpls-service"
bgp
bgp-evpn
evi 10
mpls
auto-bind-tunnel resolution any
no shutdown
sap 1/1/1:1 create
exit
-------------------------------------------------
First configure a bgp-evpn context as mpls. In addition, the minimum set of commands that must be configured to set up the EVPN-MPLS instance are the evi and the auto-bind-tunnel resolution commands.
Ensure that the EVI and the system IP are configured before executing the configure>service/vpls>bgp-evpn>mpls>no shutdown command.
The evi value, which is the EVPN instance (EVI) identifier, is unique in the system. It is used by the service-carving algorithm for multi-homing (if configured) and for auto-deriving RT and RDs in EVPN-MPLS services.
If the evi value is not specified, the value is zero and no RD or RTs are auto-derived from it. If it is specified, and no other RD or RT are configured in the service, the following applies:
the RD is derived from: system_ip:evi
the RT is derived from: autonomous-system:evi
When vsi-import and vsi-export polices are configured, the RT must be configured in the policies, and those values take precedence over the auto-derived RTs. The operational RT for a service is displayed by the show service id svc-id bgp command output. Nokia recommends that the user should not configure a VPLS ID using the bgp-ad>vpls-id command in the service.
When the evi command is configured, a config>service>vpls>bgp node (even empty) is required to output correct information using the show service id 1 bgp and show service system bgp-route-distinguisher commands.
The configuration of an EVI is enforced for EVPN services with SAPs in an ethernet-segment. See EVPN multi-homing in VPLS services for more information about ESs.
The following options are specific to EVPN-MPLS and are configured in the config>service>vpls>bgp-evpn>mpls context:
control-word
Enable or disable the control-word command to guarantee interoperability to other vendors. In accordance with RFC 7432, this command is required to avoid frame disordering.
auto-bind-tunnel
This command is used to select the type of MPLS transport tunnel used for a specific instance. The command is used in the same way as in VPRN services. See auto-bind-tunnel for more information.
For BGP-EVPN MPLS, bgp must be explicitly added to the resolution-filter in EVPN (BGP is implicit in VPRNs).
force-vlan-vc-forwarding
This command allows the system to preserve the VLAN ID and pBits of the service-delimiting qtag in a new tag added in the customer frame before sending the frame to the EVPN core.
Nokia recommends that the user should not configure the force-vlan-vc-forwarding command on the 7210 SAS-Mxp and 7210 SAS-Sx/S 1/10GE. Instead, Nokia recommends using the no force-vlan-vc-forwarding configuration, which is the default setting.
split-horizon-group
This command associates a user-created split-horizon group to all the EVPN-MPLS destinations. See EVPN and VPLS integration for more information.
The split-horizon-group command is supported only on the 7210 SAS-Mxp.
ingress-replication-bum-label
When this command is enabled, it allows the PE to advertise a label for BUM traffic (inclusive multicast routes) that is different from the label advertised for unicast traffic (with the MAC/IP routes). This is useful to avoid potential transient packet duplication in all-active multi-homing.
On the 7210 SAS, because all-active multi-homing is not supported by default, the ingress-replication-bum-label command is disabled. The user has the option to enable this command.
In addition to the preceding options, the following bgp-evpn commands are also available for EVPN-MPLS services:
[no] mac-advertisement
mac-duplication and settings
When EVPN-MPLS is established among some PEs in the network, EVPN unicast and multicast ‟bindings” to the remote EVPN destinations are created on each PE. A specified ingress PE creates the following:
a unicast EVPN-MPLS destination binding to a remote egress PE, as soon as a MAC/IP route is received from that egress PE
a multicast EVPN-MPLS destination binding to a remote egress PE, only if the egress PE advertises an inclusive multicast Ethernet tag route with a BUM label (only possible if the egress PE is configured with ingress-replication-bum-label)
These bindings, as well as the MACs learned on them, can be checked using the show commands in the following output example, where the remote PE(192.0.2.69) is configured with no ingress-replication-bum-label and PE(192.0.2.70) is configured with ingress-replication-bum-label. As a result, the device has a single EVPN-MPLS destination binding to PE(192.0.2.69) and two bindings (unicast and multicast) to PE(192.0.2.70). The following is a sample configuration output.
*A:Dut# show service id 1 evpn-mpls
===============================================================================
BGP EVPN-MPLS Dest
===============================================================================
TEP Address Egr Label Num. MACs Mcast Last Change
Transport
-------------------------------------------------------------------------------
192.0.2.69 262118 1 Yes 06/11/2015 19:59:03
ldp
192.0.2.70 262139 0 Yes 06/11/2015 19:59:03
ldp
192.0.2.70 262140 1 No 06/11/2015 19:59:03
ldp
192.0.2.72 262140 0 Yes 06/11/2015 19:59:03
ldp
192.0.2.72 262141 1 No 06/11/2015 19:59:03
ldp
192.0.2.73 262139 0 Yes 06/11/2015 19:59:03
ldp
192.0.2.254 262142 0 Yes 06/11/2015 19:59:03
bgp
-------------------------------------------------------------------------------
Number of entries : 7
-------------------------------------------------------------------------------
===============================================================================
*A:Dut# show service id 1 fdb detail
===============================================================================
Forwarding Database, Service 1
===============================================================================
ServId MAC Source-Identifier Type Last Change
Age
-------------------------------------------------------------------------------
1 00:ca:fe:ca:fe:69 eMpls: EvpnS 06/11/15 21:53:48
192.0.2.69:262118
1 00:ca:fe:ca:fe:70 eMpls: EvpnS 06/11/15 19:59:57
192.0.2.70:262140
1 00:ca:fe:ca:fe:72 eMpls: EvpnS 06/11/15 19:59:57
192.0.2.72:262141
-------------------------------------------------------------------------------
No. of MAC Entries: 3
-------------------------------------------------------------------------------
Legend: L=Learned O=Oam P=Protected-MAC C=Conditional S=Static
===============================================================================