Chapter 12.1 Managing Networking

  1. What is the simplified four-layered networking model called?
    TCP/IP network model
  2. What are the four layers of the TCP/IP network model?
    Application, Transport, Internet, and Link.
  3. Where can a list of well-known and registered ports be found?
    /etc/servicese
  4. What does the combination of the service port and IP address form?
    A socket.
  5. If a socket has a destination then it must also have?
    A source.
  6. What are some common application layer protocols?
    SSH, HTTPS, NFS or CIFS, and SMTP
  7. What does the link layer do?
    Provides connection to the physical media.
  8. In new releases of RH, network interface names start with what?
    The type of interface.

    • en for ethernet
    • wl for WLAN
    • wwan for WWAN
  9. In network interface naming what are the following:

    oN
    sN
    pMsN
    oN - onboard with device number; eno1

    sN - device is hot plug slot number N; ens3; ens3 is an Ethernet card in PCI hotplug slot 3.

    pMsN - indicates that this is a PCI device on bus M in slot N; wlp4s0
  10. What is a routing table?
    A table that tells a host how to route traffic for a particular network.
  11. What is listed in a routing table?
    The destination network, which interface to use when sending traffic and the IP address of an intermediate router required to relate the message to its final destination.
  12. If two entries on a routing table match which one is used?
    The one with the longest prefix.
  13. If network traffic does not match a specific route in the routing table where is the traffic sent?
    The default route to the entire IPv4 internet 0.0.0.0/0
  14. How can a server configure its IPv4 settings at boot time?
    From a DHCP server.
  15. How does an address issued via DHCP remain with the client?
    Request a renewal of the lease periodically.
  16. In networking, what is dual stacking?
    When IPv6 is used parallel to IPv4.
  17. T or F: It is impossible for a network interface to have an IPv6 and IPv4 assigned
    False.
  18. How many bits in an IPv6 address:
    128
  19. How many groups in an IPv6 address?
    8
  20. How many charachters in a group of an IPv6 address?
    4
  21. What are the groups of four hexadecimal characters called in an IPv6 address?
    nibbles (half-byte)
  22. Each nibble represents 4bits of an IPv6 address, how many in group?
    16
  23. Write this in a shorter manner
    2001:0db8:0000:0010:0000:0000:0000:0001
    2001:db8:0:10:0:0:0:1

    2001:db8:0:10::1
  24. A common practice when writing IPv6 letters in an address is to write them
    lower case
  25. [2001:db8:0:10::1]:80

    What is 80?
    Port number
  26. How many parts can an IPv6 address be divided into?
    Two, the network prefix and the interface ID.
  27. What does the network prefix identify
    The subnet.
  28. What does a network interface identify?
    It identifies a particular interface on the subnet.
  29. T or F: Does IPv6 have a standard subnet?
    Yes
  30. What is the subnet mask for IPv6?
    /64
  31. What will a network provider allocate for an organization?
    A shorter prefix, /48
  32. With a /48 allocation from the network provider how many bit does that leave for subnets?
    16 and a total of 65536 subnets.
  33. ::1/128
    localhost
  34. ::
    unspecified address. The IPv6 equivalent to 0.0.0.0. For a network service, this could indicate that it is listening on all configured IP addresses.
  35. ::/0
    Default route. The IPv6 equivalent to 0.0.0.0/0. The default route in the routing table matches this network; the router for this network is where all traffic, for which there is no better route, is sent.
  36. 2000::/3
    • Global Unicast Address.
    • “Normal” IPv6 addresses are currently being allocated from this space by IANA. This is equivalent to all the networks ranging from 2000::/16 through 3fff::/16.
  37. fd00::/8
    unique local address

    IPv6 has no direct equivalent of RFC 1918 private address space, although this is close. A site can use these to self-allocate a private routable IP address space inside the organization, but these networks cannot be used on the global Internet. The site must randomly select a /48 from this space, but it can subnet the allocation into /64 networks normally.
  38. fe80::/10
    Link-local addresses

    Every IPv6 interface automatically configures a link-local unicast address that only works on the local link on the fe80::/64 network. However, the entire fe80::/10 range is reserved for future use by the local link. This will be discussed in more detail later.
  39. ff00::/8
    Multicast

    The IPv6 equivalent to 224.0.0.0/4. Multicast is used to transmit to multiple hosts at the same time, and is particularly important in IPv6 because it has no broadcast addresses.
  40. Which address is unroutable?
    fe80::/64
  41. Who can you talk to on a network link that has an fe80::/64 address?
    Hosts on that link.
  42. How is an fe80:/64 address configured?
    Automatically
  43. How is the unique interface ID for a link-local address (fe80) created?
    From the network interface's Ethernet hardware address. The usual procedure to convert the 48-bit MAC address to a 64-bit interface ID is to invert bit 7 of the MAC address and insert ff:fe between its two middle bytes
  44. What must you use when using talking to link-local address on the same network?
    A scope identifier at the end of the address, it consists of % followed by the name of the network interface.

    fe80::211:22ff:feaa:bbcc%ens3
  45. Do you need to use a link identifier when using global addresses?
    No.
  46. What is multicast?
    Allows one system to send traffic to a special IP address that is received by multiple systems.
  47. Who receives multicast traffic?
    Specified systems on a network
  48. What is the broadcast address in IPv6?
    There is no bcast address in IPv6.
  49. What is the equivalent of a broadcast address in IPv6?
    ff02::1, all nodes link-local-address.
  50. How do we assign addresses to an network interfaces?
    DHCP or Statically
  51. What two addresses cannot be used in an IPv4  subnet?
    The highest and the lowest.
  52. What two interface ID are reserved in IPv6?
    all zeros, identifier 0000:0000:0000:0000 used by all routers on the link.

    The identifiers fdff:ffff:ffff:ff80 through fdff:ffff:ffff:ffff.
  53. What does a host do when it wants an IPv6 address from a DHCPv6 server?
    Essentially, a host sends a DHCPv6 request from its link-local address to port 547/UDP on ff02::1:2, the all-dhcp-servers link-local multicast group. The DHCPv6 server then usually sends a reply with appropriate information to port 546/UDP on the client's link-local address.
  54. ff02::1:2 is the....
    all-dhcp-servers link-local multicast group.
  55. In addition to DHCPv6, IPv6 also supports a second dynamic configuration method called...
    Stateless Address Autoconfiguration (SLAAC).
  56. What is the first thing a host using SLAAC does?
    Host brings up its interface with link-local fe80::/64. It then sends a “router solicitation” to ff02::2, the allrouters link-local multicast group. An IPv6 router on the local link responds to the host's link-local address with a network prefix and possibly other information. The host then uses that network prefix with an interface ID that it normally constructs in the same way that link-local addresses are constructed.
  57. Which RH8 package assists in SLAAC?
    radvd
  58. Which number is the size, in bits, of an IPv4 address?





    F.
  59. 2. Which term determines how many leading bits in the IP address contribute to its
    network address?





    E.
  60. 3. Which address represents a valid IPv4 host address on the 192.168.1.0/24 network?



    C.
  61. Which number is the size, in bits, of an IPv6 address?





    A.
  62. Which address does not represent a valid IPv6 address?






    D.
  63. Which term allows one system to send traffic to a special IP address that is received by
    multiple systems?





    A.
  64. What will the IP link command list?
    All of the available interfaces on your system.
  65. What does the IP command do?
    Use the ip command to view device and address information. A single network interface can have multiple IPv4 or IPv6 addresses.
  66. What is RX and TX?
    Packets received and transmitted.
  67. How do you show statistics for the link ens3?
    ip -s link show ens3
  68. ping -c3 192.168.1.1 does what?
    Pings that IP 3 times.
  69. What is the ping command to use on and IPv6 network?
    ping6
  70. When you ping link-local addresses and the link-local all-nodes multicast group (ff02::1), what must you do?
    You must explicitly identify the network interface with the scope identifier.

    Ex. ff02::1%ens3
  71. Can IPv6 link-local addresses be used by other hosts on the same link?
    Yes.

    ssh fe80::f482:dbff:fe25:6a9f%ens4
Author
andres666
ID
355117
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Chapter 12.1 Managing Networking
Description
Part 1 Managing Networking
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