Networking test 2

How does a router know which output link to send a packet to

It reads the IP header, then the routing algorithm consults the forwarding table

Network protocol is a service between two

hosts

A transport protocol is a service between two

processess

Main difference between IP and TCP

IP is connectionless(stateless) and best-effort and unreliable, TCP is reliable and connection oriented(stateful)

IP network is ______, TCP connections are ____________

simple complex

Why fragmentation of IP

Because the layer 2 portocol may have limited space in it's frame. Reassembbly only happens at final destination

Inet addresses are

Hierarchical

Subnetting

take some bits from the host side. The subnets are labeled in between the network and host. Each subnet has it's own broadcast

Layer 3 and 4 are controlled by

the OS

Sometimes layer 2 is controlled by the os but it it usually embedded

into the network interface card with L1.

At their core, sockets are

just some function calls made on behalf of the application developer

nodejs is written in

javascript

NAT port

the NAT port is in the router and assigns a port number to outgoing data. Incoming data comes in through that port and is then routed to the appropriate place on the network. All of the inter-network IP/ports are different than the outward facing ones

The NAT port changes the TCP header

This is ahack that works

NAT is helpful because

It limits the number of IPv4 addresses and it provides protection as individual hosts are not directly reachable from the internet

IPv6 is made up of

128 bits, 8 x 16 bit groups

::

means everything between it is 0 and can only be used once in an IPv6 address

Which 0s can be dropped in IPv6

leading 0's in each quartet

IPv6 can't have

the letters o or l

Does IPv6 have the network host arrangement

yes. /64 is half host half network