Lecture 1 - IPv4 Address Allocation, NAT Flashcards
What are the possible solutions to delay IPv4 address exhaustion?
NAT
IPv6
Reclaim unused address blocks from organisations
Name two advantages of CIDR
Route aggregation
variable sized address blocks (efficient address allocation)
How does route summarization help reduce the number of route entries?
Instead of advertising all the routes with a common prefix, we only advertise one route instead
Consider a home gateway, with a NAT, that is only allocated one global IPv4 address. How does the
NAT multiplex between connections originated by private IPv4 hosts?
Use port numbers
The STUN solution does not work for which types of NATs?
It only works for Full Cone NATs
What does ICMP stand for?
Internet Control Message Protocol
What is ICMP used for?
ICMP by network devices, like, routers to send error messages indicating, for example, that a requested service is not available or that a host or router could not be reached
What does ARP stand for?
Address Resolution Protocol
What is ARP used for?
Used by the Internet Protocol (IP) to map IP addresses to the hardware addresses used by a data link protocol
What does QoS stand for?
Quality of service
What is Route Aggregation?
Is the process routers use to take a range of IP addresses and advertising them in one address block
What is Route Aggregation also known as?
Route summarization or supernetting
What are some advantages of Route Aggregation?
minimise latency
reduce number of routing entries
reduces processor workloads, memory requirements and bandwidth demand
What does a NAT do?
rewrites source and/or destination address of IP packets as they pass through a router of firewall
What are the 4 NAT types?
Full-cone
Address restricted
Port restricted
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