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4.9 Checkpoint: a network you can describe

Run these on KALI01, since it's the machine you have.

# The four answers. Address from your DHCP pool, a gateway you can
# name, and a DNS server.
ip -brief addr
ip route
cat /etc/resolv.conf

# The debugging ladder from lesson 4.4, in order. Substitute your
# own gateway address on the first line.
ping -c 3 10.10.10.2
ping -c 3 1.1.1.1
dig +short ubuntu.com

# Who's on the network so far.
sudo nmap -sn 10.10.10.0/24

Pass criteria​

Everyone:

  • You can name all four questions a machine answers at boot, and point at where KALI01's answers came from (lesson 4.1)
  • Your lab network uses 10.10.10.0/24, with DHCP handing out .100 to .199 (lesson 4.3)
  • The addressing plan is written in Projects/lab-network.md, and matches what you built (lessons 4.3, 4.8)
  • KALI01 boots, has an address from the pool, and its password is no longer the published default (lesson 4.4)
  • All three rungs of the ladder pass from KALI01: gateway, then 1.1.1.1, then a name lookup (lesson 4.4)
  • You can explain in one sentence why the course doesn't use bridged networking (lesson 4.2)
  • You captured a DNS lookup and can say why it used UDP rather than TCP (lesson 4.7)
  • You captured the three-way handshake between your machine and KALI01, and can name the three packets in order (lesson 4.7)
  • You followed the TCP stream and read your own HTTP request back as plain text, and that capture is saved in your journal for the comparison in lesson 7.6 (lesson 4.7)
  • Given any packet, you can point at which rows in the middle pane are layers 2, 3, 4, and 7 (lessons 4.1, 4.7)

Tier 2 as well:

  • FW01 is built with WAN on the NAT network and LAN on the host-only network, and you can say which adapter is which and why the order mattered (lesson 4.5)
  • Its LAN interface is 10.10.10.254 and it serves DHCP for the segment (lesson 4.5)
  • You reached the web interface at https://10.10.10.254, and you know why the certificate warning appears and which module fixes it (lesson 4.5)
  • Inside works: with Kali temporarily on the LAN segment, it got a pool address, used 10.10.10.254 as its gateway, and reached the internet (lesson 4.6)
  • Outside is blocked: with Kali back on the NAT segment, it cannot ping 10.10.10.254 and discovers nothing on 10.10.10.0/24 (lesson 4.6)
  • Both test results are recorded in your journal with the exact commands, as the baseline Module 14 will compare against (lesson 4.6)

Green across the board means your lab has a real network with a plan behind it, which is more than a lot of production environments can say.

Module 5 is the big one: Windows Server, your first domain controller, and the moment lab.internal stops being a string in a document and starts being a domain.