lecture4PSI Flashcards

1
Q

Reasons for traffic separation

A

▶Clarity (only what belongs together is combined)
▶ Safety (traffic only goes where it belongs)
▶ Efficiency (network traffic does not mix)
▶ Simplicity (easier management)

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2
Q

What is an automatic configuration in IPv6?

A

Automatic configuration = a method whose purpose is to obtain an individual global IPv6
address and other parameters that will allow the station to communicate within the local
network and the Internet

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3
Q

Can the address 0000:0000:0000:0000:0000:0000:0000:0000 be shortened to ::::?

A

Yes

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4
Q

Hybrid VLAN network

A

A network that contains both marked and unmarked
traffic (on the trunk port as well as on the access ports)

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5
Q

In what order sre extension headers placed?

A

Behind each other

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6
Q

Where is the IPv6 packet size determined?

A

It is determined by the source station

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7
Q

Does the basic header always exist in IPv6 packet?

A

Yes

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8
Q

What is an extension header?

A

A structure that contains specific information used to deliver a
specific packet

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9
Q

How do we replace broadcast in IPv6?

A

It is replaced by specific multicast addresses

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10
Q

Where do we insert VLAN identifier in the Ethernet frame?

A

After the MAC address

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11
Q

What is global identifier in IPv6?

A

Global Identifier = a sequence of 40 bits that identifies a specific local network

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12
Q

Why the header length is ommited in IPv6 header?

A

Because it is fixed now

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13
Q

What is an inverse neighbor discovery?

A

The method can derive the corresponding IPv6 address for a known link address of a
specific interface

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14
Q

Selected principles and technologies for IPv6

A

Data routing: The method by which a station with an IPv6 address delivers data to the
destination station.
DHCPv6: An alternative to stateless configuration, similar to DHCP for IPv4.
Inverse neighbor discovery: Finding an IPv6 address to the corresponding MAC address
by the interface on which the IPv6 address is set.
IPv6 to IPv4 transition mechanism: For the reachability of addresses of a station in
IPv4 networks by stations in IPv6 networks.
TEREDO: Designed to use IPv6 in a local network that does not support IPv6. The
implementation of this technology under MS-Windows is called MIREDO.
Mobility with IPv6: A way to ensure that a particular

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15
Q

MPLS network

A

Label Edge Router(LER) attaches label to
packet when it enters MPLS network
inside the MPLS network, packets are
forwarded according labels by Label
Switch Routers(LSRs)
when packet exits the MPLS network, the
edge router removes the label

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16
Q

Name the fields that are kept in IPv6 header from IPv4 header

A

Version, Source address, Destination address

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17
Q

How does packet in IPv6 looks like?

A

Basic Header + (Extension Header)* + Data

18
Q

MultiProtocol Label Switching (MPLS)

A

In OSI model is between 2nd and 3rd layers: “layer 2.5 protocol”
adds label to layer 3 packets
packets are then switched according the label
implements end-to-end connection independent of link layer

19
Q

What is the size of IPv6 address?

A

128bits = 8 × 16bits

20
Q

Name the new fields in IPv6 header

A

Flow label, it is information for the router to identify the sequence of packets going together to a specific destination

21
Q

VLAN division

A

By ports – a specific VLAN is selected according to which specific ports on the switch are
assigned to it (can be used for smaller networks).
By addresses – a specific frame is assigned to a specific VLAN group according to the link
(MAC) address.
By protocol – the frame is assigned to a specific VLAN according to the higher layer protocol
it transmits (eg voice, video, etc.).
By tag – by attaching a tag to a frame (most common today), it is commonly referred to as a
tagged vlan.
Multiple (VLAN within VLAN, Q-in-Q)

22
Q

Name the supported address types for IPv6 according to the type of communication operations

A

Unicast, Multicast, Anycast

23
Q

VLAN

A

Virtual local area network, they are designed to be able to separate flows in network at the link layer

24
Q

What is a basic header in IPv6?

A

A structure that contains information related to basic parameters necessary
for packet delivery (eg source + destination address, TTL, data size)

25
Q

How do identify the devices that support IPv6?

A

They are marked with a special IPv6 Ready logo

26
Q

What is a neighbor discovery?

A

A full set of traffic control functions in ICMPv6. It offers a number of functions such as
▶ Automatic configuration of end stations (similar to DHCP for IPv4).
▶ Detection of link addresses in the local network (ARP replacement for IPv4).
▶ Quick update of invalid items: detection of unreachable IPv6 addresses (e.g. due to station
shutdown).
▶ Searching for routers: automatic detection through which routers traffic intended for stations
located in other networks can be forwarded.
▶ Redirection
▶ Verifying the availability of neighbors (on the local network, with known neighbors).
▶ Detection of duplicate addresses (search and deactivation of erroneous addresses)

27
Q

What type of address do we use to divide VLAN ?

A

MAC address

28
Q

What happens to the tag when the frame leaves the switch?

A

It is being removed

29
Q

2 types of automatic configuration

A

Stateful(DHCPv6) - there is a specialized server in the network that ensures the allocation of
addresses, the DHCPv6 protocol is used. In principle identical to IPv4 , Stateless(SLAAC) - based on the idea that there are routers in the network that have complete
information about traffic and can pass it on

30
Q

What are the types of addresses in IPv6?

A

Hint to remember: guillt(Group, Unique local, Individual global, Local link, Loopback, Transitional)

Local Link (LL) = addresses belonging to specific network interfaces, which are set
automatically according to the MAC addresses of these interfaces (fe80::/10).
Group (multicast) addresses (ff00::/8)
Unique Local (UL) = similar to non-public in IPv4 (fc00::/7).
Loopback (::1/128).
Undefined address (::/128).
Transitional = used for data delivery to IPv4 networks (64:ff9b::/96)
Individual global = similar to public in IPv4 (all remaining addresses)

31
Q

Mobility with IPv6

A

The station (Mobile node = MD) is assigned its own IPv6, which
it uses in the home network.
The address (MD) is routed through the home router (HR).
MD connects in some foreign network under a different IPv6
address as a ”mobile node”.
The station contacts its local HR router and reports its current
address in a foreign network.
As soon as another station (Correspondent node = CD) wants to
contact the MD, the HR arranges for the request to be forwarded
to the address that the MD reported to him from a foreign
network.
After MD receives a request from CD in a foreign network, MD
suggests to CD route optimization, i.e. sending packets directly to
an IPv6 address in a foreign network

32
Q

What is TEREDO technology?

A

The technology allows a station to communicate via IPv6, although it is not directly located
on an IPv6-supporting network

33
Q

What is subnet identifier?

A

Subnet Identifier = sequence of 16 address bits that are used for routing to a specific subnet (internal network)
within a network specified by a specific GRP

34
Q

What do we need to implement traffic forwarding between VLANs? Why do we use this?

A

Router, a
switch cannot pass traffic from one VLAN to another, as its task is to separate traffic. If data is to be forwarded, for
example, from VLAN1 to VLAN3, this data must first pass through the switch to the router

35
Q

IPv6 header concatenation

A

Extension headers are placed one behind the other in a defined order, each having a
specific function. A specific item in each header is used to concatenate headers - next header

36
Q

Routing in networks using IPv6

A

Routing = way of finding a path for data delivery between the source and destination
station, stations using IPv6 are able to discover available routers automatically using neighbour discovery

37
Q

Name the fields of IPv4 header that are not kept in IPv6 header

A

IHL, Identification, Flags, Fragment offset, Header Checksum, Options, Padding

38
Q

Can the ARP be used for IPv6?

A

ARP cannot be used (it is
not defined), it is included in the ICMPv6 protocol for detecting link addresses

39
Q

Does extension header always have to be present?

A

No

40
Q

What is GRP?

A

Global Routing Prefix (GRP) = a sequence of the first 45 bits of an IPv6 address that identifies a specific network
that is reachable within the Internet (public network)

41
Q

Trunk port

A

A port that handles multiple different VLANs.