CCNA v2.0, section 1.0, lab 1, in slides: capture a ping, an HTTP request and a DNS lookup with Wireshark or tcpdump and read their Ethernet, IP, ICMP, TCP and UDP headers; compare a TCP handshake with a UDP query; send a ping and a web request across a switch and a router in Packet Tracer, watching the MAC address table and the headers at each hop; then break that network in four ways and find where the traffic stops.
The slides
The lab is twenty-three slides in three parts, after an introduction, one step each, with the steps to follow beside a capture, a terminal or the network.
- Introduction: what the lab does, and what it needs.
- 1. Capturing on your computer
- Start a capture: Wireshark's interfaces, and tcpdump.
- Capture a ping: to the default gateway and to
1.1.1.1. - Read the headers of an echo request: Ethernet, IPv4 and ICMP, and the gateway's MAC address on both frames.
- Capture an HTTP request:
curl to http://example.com/, the handshake, the request and the page. - Read the TCP headers of the handshake: ports, flags, sequence and acknowledgement numbers.
- Capture a DNS lookup:
nslookup to 1.1.1.1, and the UDP header's four fields. - Compare the TCP handshake with the UDP query.
- 2. Following packets in Packet Tracer
- Add the servers to the guide's network: a second switch, a web server and a DNS server.
- Configure R1's second interface, the servers and the PCs, and the DNS record
www.ccna.test. - Check the network in realtime, then switch to simulation mode.
- Watch SW1 learn the MAC addresses, record the headers at each hop, and trace a web request.
- 3. Breaking the network: four faults made in the Packet Tracer network, one at a time; for each, a prediction of what stops working, the tests, and the device where the traffic stops.
The buttons on the left and right edges move between slides. So do the arrow keys and a swipe.
The files
Sources