Question : Why all other areas must be connected to ospf area 0(backbone)?

What I have read and know till now is since ospf behaves like distance vector protocol for inter area communication hence it is vulnerable to routing loops that’s why all the ABRs must be connected to ospf area0 and interarea communication happens through backbone area ….but you may ask that how distance vector in inter … More Question : Why all other areas must be connected to ospf area 0(backbone)?

ISIS Continued…

Some more details about ISIS: Packet types in ISIS : Hello Packets : Just like other IGPs ISIS also uses hello packets to form the adjacency and as a keepalive mechanism. ISIS has many hello packets intermediate system to intermediate system hello(IIHs), End system to intermediate system hellos(EIHs- sent to mac 09-00-2B-00-00-05), Intermediate system to … More ISIS Continued…