Questions about cisco packet tracer. Who fumbles?

Question

Cisco Packet Tracer

What add-on card provides single-port serial connectivity to remote offices or legacy serial network devices?
2. Specify the assignment of resource record types in the forward and reverse DNS zones.
3.Which of the following commands can be found in the CLI of a router but not a switch?
- cloc rate command;
- command ip address mask address;
- ip address dhcp command;
- interface vlan 1
command 4. Describe how the OSPF protocol works.
5.Describe all possible schemes for the operation of the NAT service.

Answer 1

yeah, 4, 5 already ran to describe
no one fumbles, even on freelance

Answer 2

1. WIC-1T
2. As far as I know, the reverse DNS record has one type of resource record - PTR (pointer) associates an IP address with a canonical name. For other entries, there is Wikipedia)
3. clock rate - clock rate on serial interfaces
4. ospf - link state protocol. The principle of operation is based on the exchange of messages between routers in the same zone, containing information about routes.
Main message types:
Hello, DBD (database description), LSR (link-state request), LSU (link-state update), LS-Ack (link-state acknowledgment).
Hello - contains neighbors
DBD - contains information from LSDB (link-state database)
LSR - requests the necessary information indicating the type of LSU
LSU - provides the necessary information or contains all the information LSA
LSAck - confirmation of receipt
As briefly as possible according to the algorithm of work:
1. Establishing neighbor relationships, choosing DR (designed router) & BDR (backup DR)
2. LSA exchange, filling the routing table
3. Permanent messaging, because trigger-dependent protocol.
5. By examples of work, briefly and abstractly, because ingress and outgress interfaces can be either lan to wan or wan to lan.
Static NAT, Dynamic NAT, PAT (port address translations)
Static - one inside ip to outside ip
Dynamic - selects outside ip from the pool and transfers to it the outgoing packet from the allowed host by ACL
PAT - many ip to 1 outside Socket (ip : port), works with Extended ACL, because work is needed on the Transport Layer (L4), according to ACL, it checks SA (source address) and transfers it to one external ip, adding a port.