Great lesson, Rene!
I studied this from the Cisco documentation but they never explained in clear terms what was going on, but you managed it!
Small typo (should be 88.88.88.88/32?):
88.88.88.88/43 via 192.168.24.4 interface GigabitEthernet0/1
Also could you provide the configs for PIC edge, at the end?
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Just came across this quote from Cisco:
PIC core ensures fast convergence for BGP routes when there is a link or node failure in the core that causes a change in the IGP reachability to a remote BGP next-hop address.
PIC edge ensures fast convergence to a BGP backup path when an external (eBGP) edge link or an external neighbor node fails.
In your example you use iBGP between PE’s for obvious reasons, so I’m a bit surprised they say PIC edge is for “external neighbours”?