EVPN-VPWS Multihomed IOS-XR (Non-Bundle)

Load init.cfg

configure
load init.cfg
commit replace
y

Configure multi-homing without using bundle interfaces.

Configure two VPWS, one for VLAN 10 and one for VLAN 20.

Configure CE1 with 10.0.10.1/24 and 10.0.20.1/24. Configure CE2 with 10.0.10.2/24 and 10.0.20.2/24. Configure these only on Gi0/0/0/1 on each CE.

Answer

#PE1, PE2
int gi0/0/0/1
 no shut
int gi0/0/0/1.10 l2transport
 encapsulation dot1q 10
int gi0/0/0/1.20 l2transport
 encapsulation dot1q 20
!
evpn
 int gi0/0/0/1
  ethernet-segment
   identifier type 0 12.12.12.12.12.12.12.12.12
!
l2vpn xc group VPWS
 p2p 10
  int gi0/0/0/1.10
  neighbor evpn evi 10 service 10
 p2p 20
  int gi0/0/0/1.20
  neighbor evpn evi 20 service 20

#PE3, PE4
int gi0/0/0/1
 no shut
int gi0/0/0/1.10 l2transport
 encapsulation dot1q 10
int gi0/0/0/1.20 l2transport
 encapsulation dot1q 20
!
evpn
 int gi0/0/0/1
  ethernet-segment
   identifier type 0 34.34.34.34.34.34.34.34.34
!
l2vpn xc group VPWS
 p2p 10
  int gi0/0/0/1.10
  neighbor evpn evi 10 service 10
 p2p 20
  int gi0/0/0/1.20
  neighbor evpn evi 20 service 20

#CE1
int gi0/0/0/1
 no shut
int gi0/0/0/1.10
 encap dot1q 10
 ip address 10.0.10.1/24
int gi0/0/0/1.20
 encap dot1q 20
 ip address 10.0.20.1/24

#CE2
int gi0/0/0/1
 no shut
int gi0/0/0/1.10
 encap dot1q 10
 ip address 10.0.10.2/24
int gi0/0/0/1.20
 encap dot1q 20
 ip address 10.0.20.2/24

Explanation

This lab demostrates the use of multi-homed EVPN without bundle interfaces. This is possible by using standalone interfaces, but the only multi-homing mode available is single-active.

We can see this is true because the only load-balancing-mode available to us is single-flow-active, which is a variation of single-active. By default, single-active is used.

Note that we have the exact same challenges as we did in the previous lab when using single-active with a bundle. Both interfaces will be up from the CE’s perspective, but the standby PE will drop received traffic.

Since we are using even numbered EVIs, the PE with the lowest RID will be active (PE1 and PE3). We can control this the same way we did in the previous lab, using manual service carving. For example, this makes PE1 active for EVI 10 and PE2 active for EVI 20:

# PE1
evpn
 interface GigabitEthernet0/0/0/1
  ethernet-segment
   identifier type 0 12.12.12.12.12.12.12.12.12
   service-carving manual
    primary 10 secondary 20

# PE2
evpn
 interface GigabitEthernet0/0/0/1
  ethernet-segment
   identifier type 0 12.12.12.12.12.12.12.12.12
   service-carving manual
    primary 20 secondary 10

On the CE, we can just place the IPs on the physical interface that connects to the active PE. I’m not sure of a robust way to automatically failover between interfaces when using single-active mode.

#CE1
int gi0/0/0/1
 no shut
int gi0/0/0/1.10
 encap dot1q 10
 ip address 10.0.10.1/24
int gi0/0/0/1.20
 encap dot1q 20
 ip address 10.0.20.1/24

#CE2
int gi0/0/0/1
 no shut
int gi0/0/0/1.10
 encap dot1q 10
 ip address 10.0.10.2/24
int gi0/0/0/1.20
 encap dot1q 20
 ip address 10.0.20.2/24