R2

show bgp summary
show bgp neighbor
show bgp neighbor 4.4.4.4
show route protocol bgp
show route protocol bgp 1.1.1.1

configure
set protocols bgp traceoptions flag state
set protocols bgp traceoptions file bgp-debug.txt
commit and-quit

monitor start bgp-debug.txt

clear bgp neighbor
clear bgp neighbor 12.12.12.1