Hello, community I am learning ospf on bird, have a question about how to identify a router is ASBR, ABR or normal RT here is my topology: +-----------------------+ +-------------------+ +-------------------+ +---------------------- - + | 172.16.34.0/30 \ / 172.16.45.0/30 \ / 172.16.56.0/30 \ / 172.16.67.0/30 | | rt3 --------------------- rt4 ------------------- rt5 --------------------- rt6 ------------------- rt7 | | area 172.16.34.0 / \ area 0.0.0.0 / \ area 172.16.56.0 / \ | +-----------------------+ +-------------------+ +----- ---------------+ + ------------------------+ OSPF RIP according to the topo, rt4 and rt5 should be ABR, rt6 should be ASBR but how to know it when using ``` show ospf lsadb show ospf state ``` here are some output rt3: ``` bird> show ospf state area 172.16.34.0 router 172.16.8.3 distance 0 network 172.16.34.0/30 metric 10 stubnet 4.8.3.0/30 metric 10 stubnet 4.8.3.4/30 metric 10 stubnet 4.8.3.8/30 metric 10 stubnet 4.8.3.12/30 metric 10 stubnet 4.8.3.100/30 metric 10 router 172.16.8.4 distance 10 network 172.16.34.0/30 metric 10 xnetwork 4.8.5.0/30 metric 20 xnetwork 4.8.5.4/30 metric 20 xnetwork 4.8.5.8/30 metric 20 xnetwork 4.8.5.12/30 metric 20 xnetwork 4.8.6.0/30 metric 30 xnetwork 4.8.6.4/30 metric 30 xnetwork 4.8.6.8/30 metric 30 xnetwork 4.8.6.12/30 metric 30 xnetwork 172.16.45.0/30 metric 10 xnetwork 172.16.56.0/30 metric 20 xrouter 172.16.8.5 metric 10 xrouter 172.16.8.6 metric 20 network 172.16.34.0/30 dr 172.16.8.4 distance 10 router 172.16.8.4 router 172.16.8.3 other ASBRs router 172.16.8.6 external 4.8.7.0/30 metric2 10000 external 4.8.7.4/30 metric2 10000 external 4.8.7.8/30 metric2 10000 external 4.8.7.12/30 metric2 10000 bird> show ospf lsadb Global Type LS ID Router Sequence Age Checksum 0005 4.8.7.3 172.16.8.6 80000015 1640 baee 0005 4.8.7.4 172.16.8.6 80000015 1640 b0f7 0005 4.8.7.11 172.16.8.6 80000015 1640 6a37 0005 4.8.7.12 172.16.8.6 80000015 1640 6040 Area 172.16.34.0 Type LS ID Router Sequence Age Checksum 0001 172.16.8.3 172.16.8.3 80000019 869 0163 0001 172.16.8.4 172.16.8.4 80000016 1211 2777 0004 172.16.8.5 172.16.8.4 80000015 1208 e288 0004 172.16.8.6 172.16.8.4 80000015 1206 3d23 0002 172.16.34.2 172.16.8.4 80000015 1211 f7d6 0003 172.16.45.3 172.16.8.4 80000016 1211 58f2 0003 172.16.56.3 172.16.8.4 80000015 1208 45f1 0003 4.8.5.3 172.16.8.4 80000015 1208 69b1 0003 4.8.5.4 172.16.8.4 80000015 1208 5fba 0003 4.8.5.11 172.16.8.4 80000015 1208 19f9 0003 4.8.5.12 172.16.8.4 80000015 1208 0f03 0003 4.8.6.3 172.16.8.4 80000002 1446 e83a 0003 4.8.6.4 172.16.8.4 80000002 1446 de43 0003 4.8.6.11 172.16.8.4 80000002 1446 9882 0003 4.8.6.12 172.16.8.4 80000002 1446 8e8b ``` rt6: ``` bird> show ospf state area 172.16.56.0 router 172.16.8.5 distance 10 network 172.16.56.0/30 metric 10 xnetwork 4.8.3.0/30 metric 30 xnetwork 4.8.3.4/30 metric 30 xnetwork 4.8.3.8/30 metric 30 xnetwork 4.8.3.12/30 metric 30 xnetwork 4.8.3.100/30 metric 30 xnetwork 4.8.5.0/30 metric 10 xnetwork 4.8.5.4/30 metric 10 xnetwork 4.8.5.8/30 metric 10 xnetwork 4.8.5.12/30 metric 10 xnetwork 172.16.34.0/30 metric 20 xnetwork 172.16.45.0/30 metric 10 xrouter 172.16.8.3 metric 20 xrouter 172.16.8.4 metric 10 router 172.16.8.6 distance 0 network 172.16.56.0/30 metric 10 stubnet 4.8.6.0/30 metric 10 stubnet 4.8.6.4/30 metric 10 stubnet 4.8.6.8/30 metric 10 stubnet 4.8.6.12/30 metric 10 external 4.8.7.0/30 metric2 10000 external 4.8.7.4/30 metric2 10000 external 4.8.7.8/30 metric2 10000 external 4.8.7.12/30 metric2 10000 network 172.16.56.0/30 dr 172.16.8.6 distance 10 router 172.16.8.6 router 172.16.8.5 bird> show ospf lsadb Global Type LS ID Router Sequence Age Checksum 0005 4.8.7.3 172.16.8.6 80000015 1698 baee 0005 4.8.7.4 172.16.8.6 80000015 1698 b0f7 0005 4.8.7.11 172.16.8.6 80000015 1698 6a37 0005 4.8.7.12 172.16.8.6 80000015 1698 6040 Area 172.16.56.0 Type LS ID Router Sequence Age Checksum 0004 172.16.8.3 172.16.8.5 80000015 1267 550d 0004 172.16.8.4 172.16.8.5 80000015 1267 e684 0001 172.16.8.5 172.16.8.5 80000017 1229 ec83 0003 172.16.34.3 172.16.8.5 80000015 1267 321a 0003 172.16.45.3 172.16.8.5 80000015 1315 54f6 0003 4.8.3.3 172.16.8.5 80000015 1267 dd34 0003 4.8.3.4 172.16.8.5 80000015 1267 d33d 0003 4.8.3.11 172.16.8.5 80000015 1267 8d7c 0003 4.8.3.12 172.16.8.5 80000015 1267 8385 0003 4.8.3.100 172.16.8.5 80000006 932 2e91 0003 4.8.5.3 172.16.8.5 80000015 1315 fe25 0003 4.8.5.4 172.16.8.5 80000015 1315 f42e 0003 4.8.5.11 172.16.8.5 80000015 1315 ae6d 0003 4.8.5.12 172.16.8.5 80000015 1315 a476 0001 172.16.8.6 172.16.8.6 80000016 1510 6d45 0002 172.16.56.2 172.16.8.6 80000015 1273 2989 ```