Configuring the Local Ethernet Segment Parameters

• Configure the EVPN address family Ethernet Segment parameters, domain local, and enter the Ethernet Segment configuration mode:

  switch(config-router-bgp-af)# evpn ethernet-segment domain local
  switch(config-evpn-es-domain-local)#

• Add the 10 octet identifier, 0011:1111:1111:1111 for the local domain:

  switch(config-evpn-es-domain-local)# identifier 0011:1111:1111:1111

• Add the low-order six (6) bytes of the ES-Import Route Target, 11:11:11:11:11:11:

  switch(config-evpn-es-domain-local)# route-target import 11:11:11:11:11:11

  Exit the domain local configuration mode.

  switch(config-router-bgp-af)#

Configuring the Remote Ethernet Segment Parameters

• Configure the Ethernet Segment remote domain parameters by entering the remote domain configuration mode:

  switch(config-router-bgp-af)# evpn ethernet-segment domain remote
  switch(config-evpn-es-domain-remote)#

• Add the 10 octet identifier, 0022:2222:2222:2222 for the remote domain:

  switch(config-evpn-es-domain-remote)# identifier 0022:2222:2222:2222

• Add the low-order six (6) bytes of the ES-Import Route Target to the remote domain:

  switch(config-evpn-es-domain-remote)# route-target import 22:22:22:22:22:22

  Exit the remote domain configuration mode, and return to the Ethernet Segment configuration mode:

  switch(config-evpn-es-domain-remote)# exit
  switch(config-router-bgp-af)#

Adding the Layer 2 and BGP FEC Parameters

• Configure the Layer 2 and BGP FEC parameters for the Ethernet Segment configuration:

  switch(config-router-bgp-af)# layer-2 fec in-place update

  Exit to the global configuration mode:

  switch(config)#

Adding the Routing Control Functions

• Enter the routing control functions configuration mode and then the control-functions configuration mode:

  switch(config)# router general
  switch(config-router-general)# control-functions
  switch(config-router-general-control-functions)#

• Finally, add the JSON code to the configuration:

  switch(config-router-general-control-functions)# code
  Enter RCF code. Type 'EOF' on its own line to end.
                          function evpnDciMhBlockGwTx() {
                              if evpn.route_type is EVPN_IMET
                              {
                              community add {1:1};
                              }
                              return true;
                              }
                              
                              function evpnDciMhBlockGwRx() {
                              return community has_none {1:1};
                              }
                              
                              EOF

Displaying the Multihome EVPN Configuration

To display your configuration, use the show active command from the BGP configuration mode:

GW-A1(config-router-bgp)# show active
                router bgp 64512
                ...
                maximum-paths 4 ecmp 4
                bgp bestpath d-path
                ...
                !
                vlan 10
                rd evpn domain all 10.255.1.1:10
                route-target import export 64500:10
                route-target import export evpn domain remote 64501:10
                redistribute learned
                !
                vrf red
                rd 10.255.1.1:0
                route-target import evpn 64500:20000
                route-target export evpn 64500:20000
                router-id 10.255.1.1
                ...
                address-family evpn
                neighbor WAN-RR activate
                neighbor WAN-RR domain remote
                neighbor RR-A activate
                neighbor RR-A rcf in evpnDciMhBlockGwRx()
                    neighbor RR-A rcf out evpnDciMhBlockGwTx()
                    neighbor WAN-RR rcf in evpnDciMhBlockGwRx()
                    neighbor WAN-RR rcf out evpnDciMhBlockGwTx()
                    domain identifier 1:1
                    domain identifier 1:2 remote
                ...
                !
                evpn ethernet-segment domain local
                    identifier 0011:1111:1111:1111:1111
                    route-target import 11:11:11:11:11:11
                !
                evpn ethernet-segment domain remote
                    identifier 0022:2222:2222:2222:2222
                    route-target import 22:22:22:22:22:22
                !
                layer-2 fec in-place update
                !
                router general
                    control-functions
                    code
                    function evpnDciMhBlockGwTx() {
                    if evpn.route_type is EVPN_IMET
                    {
                    community add {1:1};
                    }
                    return true;
                    }
                    
                    function evpnDciMhBlockGwRx() {
                    return community has_none {1:1};
                    }
                

For route loop detection, configure domain identifiers for the local and remote domain, and the domain path best path. Use the same identifier for the same domain on all gateways in one site, and configure RCF rules to reject the IMET routes from peer gateways in the same DC.

Displaying iBGP PE-CE Protocol Information

EOS adds a new parameter in the output, evpn prefix detail to display the ATTR_SET, code 128 attributes.

switch#show bgp evpn
BGP routing table information for VRF default
Router identifier 10.11.0.1, local AS number 300
BGP routing table entry for ip-prefix 172.10.11.12/24, Route Distinguisher: 100:1
 Paths: 1 available
  Local
     - from - (0.0.0.0)
     Origin IGP, metric -, localpref -, weight 0, valid, internal, best
     Extended Community: Route-Target-AS:100:1 TunnelEncap:tunnelTypeMpls
     Rx path id: 0x0
     MPLS label: 100000
     Customer attributes (Origin ASN 1000)
     Origin IGP, metric -, localpref 150, internal
     Community: 47872:6 47872:6939