hi community, I got some confused of ospf lsa3. topology: r1 --a12-- r2 --a0-- r3 --a34-- r4 | | +---a23 ---+ r1(intf:r1r2) and r2(intf:r2r1) are belong to area 12, ptp network: 10.0.12.0/30 r2(intf:r20r30) and r3(intf:r30r20) are composed to area 0, ptp network: 10.0.100.0/30 r2(intf:r2r3) and r3(intf:r3r2) are composed to area 0, ptp network: 10.0.23.0/30 r3(intf:r3r4) and r4(intf:r4r3) are cmposed to area 34, ptp network: 10.0.34.0/30 r1 has a stub net: 10.1.1.0/30 r4 has a stub net: 10.4.2.0/30 why r2/r3 regenerated lsa3 and advertise on area 23, isn't it prohibited ABR to flood lsa3 to non-backbone area? r2 ``` bird> s o l type 3 area 23 Area 0.0.0.23 Type LS ID Router Sequence Age Checksum 0003 10.0.12.3 10.0.0.2 80000004 1088 6885 0003 10.0.34.3 10.0.0.2 80000004 1064 d9f3 0003 10.0.100.3 10.0.0.2 80000004 1088 9cf8 0003 10.1.1.3 10.0.0.2 80000004 1070 3ab3 0003 10.4.2.3 10.0.0.2 80000004 1060 6f70 0003 10.0.12.3 10.0.0.3 80000004 1063 c61c 0003 10.0.34.3 10.0.0.3 80000004 1069 6f67 0003 10.0.100.3 10.0.0.3 80000004 1069 96fd 0003 10.1.1.3 10.0.0.3 80000004 1063 984a 0003 10.4.2.3 10.0.0.3 80000004 1062 05e3 ```