Can someone explain why this xconnect link requires a static route to lo0 to bring S2 up??

I've been playing around with xconnect config and got stuck trying to bring the link up fully, I tried everything I could think of but no dice, after adding a static route to the lo0 address it came up successfully.

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Can anyone explain to me why and if there is something required elsewhere to bring this up without:

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Xconnect2 is directly connected to Xconnect 1 - config is identical in reverse IP order

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Xconnect2#show xconnect all

Legend: XC ST=Xconnect State S1=Segment1 State S2=Segment2 State

UP=Up DN=Down AD=Admin Down IA=Inactive

SB=Standby HS=Hot Standby RV=Recovering NH=No Hardware

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XC ST Segment 1 S1 Segment 2 S2

------+---------------------------------+--+---------------------------------+--

UP pri ac Gi0/1:3(Ethernet) UP mpls 10.255.1.1:911UP

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Xconnect2#show mpls forwarding-table

Local Outgoing Prefix Bytes Label Outgoing Next Hop

Label Label or Tunnel Id Switched interface

17 No Label l2ckt(911) 3033 Gi0/1 point2point

Xconnect2#

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Xconnect2#show ip int br

Interface IP-Address OK? Method Status Protocol

GigabitEthernet0/0 10.1.1.2YES NVRAM up up

GigabitEthernet0/1 unassigned YES NVRAM up up

GigabitEthernet0/2 unassigned YES NVRAM administratively down down

GigabitEthernet0/3 unassigned YES NVRAM administratively down down

Loopback0 10.255.255.1YES manual up up

Xconnect2#

Xconnect2#show run int Loopback0

Building configuration...

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Current configuration : 90 bytes

!

interface Loopback0

description BGP LINK

ip address 10.255.255.1 255.255.255.255

end

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Xconnect2#

Xconnect2#show run int GigabitEthernet0/0

Building configuration...

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Current configuration : 220 bytes

!

interface GigabitEthernet0/0

description WAN LINK TO XCONNECT1

mtu 9216

ip address 10.1.1.2 255.255.255.0

ip mtu 1552

duplex auto

speed auto

media-type rj45

mpls mtu 1552

mpls label protocol ldp

mpls ip

end

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Xconnect2#

Xconnect2#show run | b r b

router bgp 111

bgp log-neighbor-changes

redistribute connected

neighbor 10.1.1.1 remote-as 222

!

ip forward-protocol nd

!

!

no ip http server

no ip http secure-server

ip route 10.255.1.1 255.255.255.255 GigabitEthernet0/0

!

!

!

mpls ldp router-id Loopback0