PICOS version 4.0 and higher offer both Symmetric and Asymmetric routing for BGP EVPN hosts. In this document we will examine the case of Asymmetric EVPN routing with two hosts in different VNIs on two devices, R1 and R2.
Figure 1 depicts how packet exchange between two hosts occurs in asymmetric BGP EVPN routing model. In the asymmetric routing model, the two end hosts, Host1 and Host2 are in two different VLANs and different VNIs. Host1 intends to communicate with Host2, sends a packet with destination MAC address of of R1 because R1 is configured as the gateway on Host1. On R1, the gateway is configured on an interface that belongs to VNI Y. The packet from Host1 on ingress at R1 is first routed to VNI Y within R1 and then bridged to R2 over the VXLAN tunnel VNI Y. On receiving the packet, R2 will strip off the VXLAN header and forward the packet to Host2.
...
Step 1: Configure VLAN ID, L3 VLAN interfaces loopback interfaces and IP addressing. The MTU value of layer 3 interfaces is set to 1450 to ensure there is enough space for the overlay VXLAN header. The switch will complain and refuse to commit the configuration if MTU size is not set to 1450. Interface te-1/1/10 connects to PC1.
| Code Block |
|---|
admin@R1# set evpn vrf vrf1 vni 100 prefix-routes-only admin@R1# set interface gigabit-ethernet te-1/1/1 family ethernet-switching native-vlan-id 4094 admin@R1# set interface gigabit-ethernet te-1/1/2 family ethernet-switching native-vlan-id 10 admin@R1# set interface gigabit-ethernet te-1/1/10 family ethernet-switching native-vlan-id 10 admin@R1# set l3-interface loopback lo address 1.1.1.1 prefix-length 32 admin@R1# set l3-interface loopback vrf1 address 201.201.201.201 prefix-length 32 admin@R1# set l3-interface vlan-interface vlan4094 mtu 1450 admin@R1# set l3-interface vlan-interface vlan4094 address 40.94.0.2 prefix-length 24 admin@R1# set l3-interface vlan-interface vlan10 vrf "vrf1" admin@R1# set l3-interface vlan-interface vlan10 mtu 1450 admin@R1# set l3-interface vlan-interface vlan10 address 10.1.1.201 prefix-length 24 admin@R1# set l3-interface vlan-interface vlan1111 vrf "vrf1" admin@R1# set l3-interface vlan-interface vlan1111 router-mac 00:16:16:16:16:16 admin@R1# set l3-interface vlan-interface vlan1111 mtu 1450 admin@R1# set vlans vlan-id 10 l3-interface "vlan10" admin@R1# set vlans vlan-id 30 l3-interface "vlan30" admin@R1# set vlans vlan-id 1111 l3-interface "vlan1111" admin@R1# set vlans vlan-id 4094 l3-interface "vlan4094" admin@R1# set vxlans source-interface lo address 1.1.1.1 admin@R1# set vxlans vni 100 vlan 1111 admin@R1# set vxlans vni 10 vlan 10 admin@R1# set vxlans vni 30 vlan 30 |
...
Step 1: Configure VLAN ID, L3 VLAN interfaces loopback interfaces and IP addresses. Interface ge-1/1/10 connects to PC2.
| Code Block |
|---|
root@R2# set evpn vrf vrf1 vni 100 prefix-routes-only root@R2# set interface gigabit-ethernet ge-1/1/1 family ethernet-switching native-vlan-id 4094 root@R2# set interface gigabit-ethernet ge-1/1/310 family ethernet-switching native-vlan-id 30 root@R2# set l3-interface loopback lo address 2.2.2.2 prefix-length 32 root@R2# set l3-interface loopback vrf1 address 134.134.134.134 prefix-length 32 root@R2# set l3-interface vlan-interface vlan1111 vrf "vrf1" root@R2# set l3-interface vlan-interface vlan1111 router-mac 00:14:14:14:14:14 root@R2# set l3-interface vlan-interface vlan1111 mtu 1450 root@R2# set l3-interface vlan-interface vlan30 vrf "vrf1" root@R2# set l3-interface vlan-interface vlan30 mtu 1450 root@R2# set l3-interface vlan-interface vlan30 address 30.1.1.134 prefix-length 24 root@R2# set l3-interface vlan-interface vlan4094 mtu 1450 root@R2# set l3-interface vlan-interface vlan4094 address 40.94.0.1 prefix-length 24 root@R2# set vlans vlan-id 10 l3-interface "vlan10" root@R2# set vlans vlan-id 30 l3-interface "vlan30" |
...
| Code Block |
|---|
admin@R2# run show vxlan evpn route VRF-ID ROUTE NextHop VNI Interface -------- ---------------- ------------- ---------- ----------------- 1 11.11.11.166201/32 1.1.1.1 100 vlan1111 1 166.166.166.166/32 1.1.1.1 100 vlan1111 2 166.166.166.2/32 1.1.1.1 200 vlan2222 |
To check the VXLAN tunnels on either devices, run the command run show vxlan tunnel.
| Code Block |
|---|
admin@R2# run show vxlan tunnel
Total number of tunnels: 5
VNI 10, Encap:service-vlan-delete, Decap:service-vlan-add-replace
src addr:2.2.2.2, dst addr:1.1.1.1, state:UP
traffic type:unicast
Vtep type:EVPN
nexthops:40.94.0.2
output ports:ge-1/1/1
VNI 30, Encap:service-vlan-delete, Decap:service-vlan-add-replace
src addr:2.2.2.2, dst addr:1.1.1.1, state:UP
traffic type:all
Vtep type:EVPN
nexthops:40.94.0.2
output ports:ge-1/1/1
VNI 40 |
To check the VXLAN tunnels on either devices, run the command run show vxlan tunnel.
| Code Block |
|---|
admin@R2# run show vxlan tunnel Total number of tunnels: 3 VNI 10, Encap:service-vlan-delete, Decap:service-vlan-add-replace src addr:2.2.2.2, dst addr:1.1.1.1, state:UP traffic type:allunicast Vtep type:EVPN nexthops:40.94.0.2 output ports:ge-1/1/1 VNI 10030, Encap:service-vlan-delete, Decap:service-vlan-add-replace src addr:2.2.2.2, dst addr:1.1.1.1, state:UP traffic type:unicastall Vtep type:EVPN nexthops:40.94.0.2 output ports:ge-1/1/1 VNI 200100, Encap:service-vlan-delete, Decap:service-vlan-add-replace src addr:2.2.2.2, dst addr:1.1.1.1, state:UP traffic type:unicast Vtep type:EVPN nexthops:40.94.0.2 output ports:ge-1/1/1 |