slides19 Flashcards
slow convergence
Meanwhile real data packets are bouncing forwards and back between the routers
The local information that distance vector provides is not enough
path vector protocol
A path vector protocol is a network routing protocol which maintains the path information that gets updated dynamically. Updates which have looped through the network and returned to the same node are easily detected and discarded. This algorithm is sometimes used in Bellman–Ford routing algorithms to avoid “Count to Infinity” problems.
2018 hack on the cryptocurrency website MyEtherWallet.com
That incident involved the hijacking of Amazon DNS servers, leading to the clandestine redirection of browsers to an exact replica of the MEW webpage – one specifically built to steal private keys and siphon funds.
Resource Public Key Infrastructure
A public key infrastructure (PKI) is a set of roles, policies, and procedures needed to create, manage, distribute, use, store & revoke digital certificates and manage public-key encryption
Resource Public Key Infrastructure (RPKI), also known as Resource Certification, is a specialized public key infrastructure (PKI) framework designed to secure the Internet’s routing infrastructure.
RIP in pepperoni
The Routing Information Protocol (‘RIP’) is one of the oldest distance-vector routing protocols which employ the hop count as a routing metric. RIP prevents routing loops by implementing a limit on the number of hops allowed in a path from source to destination. The largest number of hops allowed for RIP is 15, which limits the size of networks that RIP can support.
Dijkstra’s algorithm and OSPF
Dijkstra’s algorithm to find the shortest path between a and b. It picks the unvisited vertex with the lowest distance, calculates the distance through it to each unvisited neighbor, and updates the neighbor’s distance if smaller. Mark visited (set to red) when done with neighbors.
OSPF is a widely used IGP in large enterprise networks. IS-IS, another LSR-based protocol, is more common in large service provider networks.
what are the three kinds of addresses
physical, network and human
what is /etc/hosts
Before the advent of a distributed domain name system; networked computers used local files to map hostnames to IP addresses. On Unix systems this file was named /etc/hosts or “the hosts file”. In those days, networks were small and managing a file with a handful of hosts was easy. However as the networks grew so did the methods of mapping hostnames and IP addresses.
what do APs do
An AP connects directly to a wired local area network, typically Ethernet, and the AP then provides wireless connections using wireless LAN technology, typically Wi-Fi, for other devices to use that wired connection. APs support the connection of multiple wireless devices through their one wired connection.
who manages the root
The root of the tree is called . (dot) and this label is currently managed by the Internet Corporation for Assigned Names and Numbers (ICANN)
what does managing means
“Manage” means they keep the lookup tables for that level and they say who can get labels in the next level
where are the name-to-IP-address mapping of the hosts kept
At the lowest levels, before the leaves of the tree (the hosts), the relevant organisation keeps the name-to-IP-address mapping of the hosts
what do DNS servers do
DNS servers do two things
(a) Keep the table of name to IP address mappings for the domain
(b) Help the local hosts when they need to do a lookup of non-local addresses
how does a host know where the dns server is
Every host has the IP addresses of one or more local nameservers, typically in a file (e.g., /etc/resolv.conf) that was set up by an administrator or was created by DHCP
what if your local dns server doesnt know what ip to assign
The Bath server sends a start of authority (SOA) request to a random top level server to find who is responsible for the uk label
