ccna interview questions

ccna interview questions. Checksum: checksum of the entire packet. Authentication type: Authentication type includes 3 types, where 0 means no authentication, 1 means simple password authentication, 2 meansMD5 authentication.8 Authentication: required information for packet authentication; if Authentication Type 0, this field is not checked; if Authentication Type 1, this field contains a passphrase of up to 64 bits; if Authentication Type 2, this field contains the Key ID, the length of the authentication data, and an encrypted sequence number that does not decrease (to prevent replay attacks). This digest message is appended to the end of the OSPFv2 packet and is not part of the OSPFv2 packet itself.9 Network Mask: The subnet mask of the interface on which the OSPFv2 packet is sent. 10 Hello interval: the time interval in seconds between 2 consecutive Hello packets being sent. . Router Priority: used for DR/BDR election in the range of 0.255. . Router Dead interval: the maximum time to wait before declaring a neighboring router invalid. . Designated Router (DR): IP address of the router interface for the DR. if not available. this field is 0.0.0.0. . Backup Designated Router (BDR): The router interface IP address of the BDR. if not available. the field is 0.0.0.0. . Neighbor List: Lists the OSPF router IDs of the neighboring routers that have established a neighbor relationship. 2.2. DBD (Database Description)DBD (DatabaseDescription) contains an abbreviated list of the sender router's link state database, which the receiver router uses to compare this packet with its local link state database. The LSDBs of all link-state routers in the same area must be consistent in order to construct an accurate SPF tree. o The OSPFv2DBD packet format is shown in Figure 17-2, with the meanings of the fields, except for the packet header, as described below.1 Interface MTU: The size of the maximum IP packet that the router interface can send without packet segmentation. 2 I: Initial bit, first DBD packet sent I position 1,subsequent DBD packets I position 0. 3 M: Successor bit, last DBD packet sent M position 0,other M position 1..298.Cisco Networking Lab CCNA Lab Guide (Release 2)0SPFV2