/26 这么算: 32-26=6 2的6次方=64 64-1=63 所以反掩码 0.0.0.63
因为多区域一定要通过area 0
R2作为ABR,同时宣告 area 0, 1,2
R3的直连网段宣告为area 1
R4的直连网段宣告为area 2
R2下:
router ospf 20
network 10.0.0.16 0.0.0.3 area 0
network 10.0.0.0 0.0.0.3 area 1
network 10.0.0.4 0.0.0.3 area 2
R3下:
router ospf 30
network 10.0.0.0 0.0.0.3 area 1
network 192.168.0.0 0.0.0.127 area 1
R4下:
router ospf 40
network 10.0.0.4 0.0.0.3 area 2
network 192.168.0.128 0.0.0.63 area 2
OSPF的宣告是反掩码的呀,如果是16位掩码的话,宣告的反掩码就应该是0.0.0.63