If we wanted to use single-active multi-homing on PE-1 and PE-2 instead of all-active multi-homing, we would only need to modify the following:
change the LAG configuration to single-active
The CE-12 is now configured with two different LAGs, therefore, the key/system-id/system-priority must be different on PE-1 and PE-2
change the Ethernet-segment configuration to single-active
No changes are needed at service level on any of the three PEs.
The differences between single-active versus all-active multi-homing are highlighted in bold in the following example excerpts:
A:PE1# configure lag 1
A:PE1>config>lag# info
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mode access
encap-type dot1q
port 1/1/2
lacp active administrative-key 1 system-id 00:00:00:00:69:69
no shutdown
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A:PE1>config>lag# /configure service system bgp-evpn
A:PE1>config>service>system>bgp-evpn# info
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route-distinguisher 192.0.2.69:0
ethernet-segment "ESI-71" create
esi 0x01000000007100000001
es-activation-timer 10
service-carving
mode auto
exit
multi-homing single-active
lag 1
no shutdown
exit
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A:PE2# configure lag 1
A:PE2>config>lag# info
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mode access
encap-type dot1q
port 1/1/3
lacp active administrative-key 1 system-id 00:00:00:00:72:72
no shutdown
----------------------------------------------
A:PE2>config>lag# /configure service system bgp-evpn
A:PE2>config>service>system>bgp-evpn# info
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route-distinguisher 192.0.2.72:0
ethernet-segment "ESI-71" create
esi 0x01000000007100000001
es-activation-timer 10
service-carving
mode auto
exit
multi-homing single-active
lag 1
no shutdown
exit
----------------------------------------------