Questions to self-check understanding of individual topics

Petr Grygárek
petr.grygarek@vsb.cz

1.

List basic ICMP messages and describe real scenerios, when every single mesage is generated.
Create IP addressing plan for WAN using Variable Lenght Subnet Mask (VLSM)
Provide examples of usage of Option field of IP packet header.
Describe fields in IP header used in connection with fragmentation and how they are used..
Explain IP address summarization. What it can be useful for ?
Explain the function of Proxy ARP. When it can be useful ?

Describe meaning IPv6 packet header of fields.
Describe the principle of IPv6 header chainging. What advantages it brings ?
Describe the structure of IPv6 address. How do we write IPv6 addresses (including abbreviated form) ?
Describe the meaning of 'anycast' transmission.
Explain the mechanism used in IPv6 instead of legacy ARP. How are IPv6 addresses incorporated into DNS ?

Explain the meaning of individual fields of TCP segment header. Which parameters uniquely identify connection of two communicating processes ?
Explain how can sender detect a TCP segment loss and how it wil react.
Explain the principle and purpose of Nagle algorithm and mechanism of delayed acknowledment
Describe the process of establishing and closing of TCP connection.
Describe the flow-control mechanism used to control sender transmission based on receiver buffer's remaining capacity.
Describe the principle of slow start of the TCP connection. When the slow start takes action ? What is it's purpose ?
Describe the principle TCP uses to avoid congestion.

List criteria used to classify routing protocols. Explain the difference between interior and exterior routing protocols.
Explain basic principles of distance-vector routing protocols. Which information is passed, between which routers, how often ? How the router builds it's routing table based on incoming routing information ? Which timers are used in distance-vector protocols operation ?
Describe the problem of counting-to-infinity and Split Horizon, Poisson Reverse and Route Poissoning techniques.
Why do distance-vector protocols use holddown timer ? How it works and what negative impact it has on network convergence ?
Describe basic characteristics of RIP version 1 and 2 and specify restrictions for their usage.

Describe the steps of link-state routing protocol operation taken to build-up topology database and routing table of every router.
Why link-state protocols commonly use the principle of hierarchical routing ? What are it's advantages and disadvantages ? How can it be implemented in OSPF using areas ? How we call routers inside area, on the area boundary or on the autonomous system boundary in OSPF ? Why it is useful to have hierarchical IP addressing plan corresponding to the area structure ?
How OSPF checks for neighbor router failure and which action are taken when a failure is detected ?
Why OSPF uses designated router and what is it's function ? What will happen if designated router fails ?
Which OSPF area types do you know ? Why there are various area types ? Which LSA types are propagated in individual area types ? Which routes will routers of various area types have in their topology databases and routing tables ?

Compare link-state and distance-vector routing protocols based of the following properties:

List possibilities how to influence route selection in the network..
Whatt metrics are used common routing protocols ? What is a limitation of every metric type ? What does "composite metric" mean ?
What kinds of load balancing do you know ? Which routing protocols support load balancing of every kind ?
Which reasons may lead to usage of multiple routing protocols in a single network ? How router handles routes learned from multiple routing protocols simultaneously ?
Explain the principle of route redistribution. Why do we use redistribution ? Which problems can we enconter when using redistribution ?
What is the principle of floating static route ? How we can use it ?
How we can propagate default route using routing protocol ? In what scenerio it can be useful ?
What is a difference of route filtering in distance-vector and link-state routing protocols ?
Describe principle of route summarization. What is advantage of summarization ? Where summarization takes place ? What are conditions to summarize address range ?
What is a principle of policy routing ? What it can be used for ?

7,8

Describe the term "autonomous system". Why is Internet divided into autonomous systems ?
Describe the principle of hierarchical routing and function of interior and exterior routing protocols in hierarchical routing.
List types of autonomous systems and difference in their properties.
Where can we find BGP protocol ? What transport layer protocol does it use ? What information are transferred in BGP protocol ?
Describe the principle of passing routes and route selection based on "path vector" algorithm used in BGP.
How the administrator can influence route selection in BGP based on prefix filtering and attribute manipulation ?
What are possibilities of attribute value setting and manipulation in BGP ? How we can influence route selection by attributes ?

How we can classify BGP attributes ?
Describe the purpose of BGP table (BGP database) and basic principles how routes for routing table are selected from BGP database.
Describe the problem of synchronization of BGP routes with interior routing protocol in transit autonomous system.
Describe usage of AS-PATH, NEXT-HOP, LOCAL-PREFERENCE, and MULTI-EXIT-DISCRIMINATOR attributes.

List parameters of data transmission which determine the Quality of Service provided by network. What can influence values of these parameters ?
Describe the difference between Differentiated Services and Integrated Services QoS models. What are their advantages and disadvantages ?
Describe how and why do we classify network traffic. Where classification takes place, which classification criteria can be used, how is the classification associated with packet/frame. How can packet/frame classification influence it's further processing ?
Describe the principle of Traffic Policing and Traffic Shaping and their typical usages.
What queuing mechanisms do you know ? What are their advantages, disadvantages and typical usages ?
Describe the purpose and principle of congestion avoidance using (Weighted) Random Early Discard.
Describe the basic steps to implement QoS mechanisms in the network..

10.

Describe advantages of multicast transmission. What applications typically use multicasting ?
What are characteristics of multicast groups in IP protocol ?
What addresses are used for multicast groups in IP protocol ?
Describe the way IP addresses are mapped to respective MAC addresses. Is the mapping unique ? How is non-uniqueness solved ?
What is IGMP used for and how it operates ?
Describe how can switches process multicasts. Explain the principle of IGMP Snooping technique.
Describe the usage of multicast distribution tree. Describe difference between Shortest-Path Tree and Shared Tree. What are advantages and disadvantages of these tree types ?
What is a difference between dense and sparse mode of multicast tree construction ?
Explain the principle of multicast routing based on Reverse Path Forwarding.
What routing protocols for multicast routing do you know ? What format have records of multicast routing table created as a result of multicast protocol operation ?

11.

Explain the function and advantages of Layer 3 switches.
What are the options of inter-VLAN routing ?
Describe the principle of Spanning Tree protocol operation.
Compare characteristics of Rapid Spanning Tree, Common Spanning Tree, Per-VLAN Spaning Tree a Multi-instance Spanning Tree protocols.