tpyo kingg
Posts: 664
Joined: Mon Apr 09, 2018 5:26 pm
Location: N. Finland

Need advice - practical networking tutoring

Sat Jan 11, 2020 6:36 am

I've been doing a series of small, introductory, 12-hour tutorials spread out over half a dozen sessions, each at a pre-college level, which have included use of the Raspberry Pi. I'm thinking about doing one on packet filtering and would like advice on the content. What I have so far is an outline for five parts, but wonder what I should have for the sixth part and what have I missed (or can remove) from the first five 2-hour blocks?

1. LAN versus WAN
+ ping
+ traceroute
+ nmap
+ tcpdump
+ dig

2. UDP, TCP, ICMP
+ 7 OSI layers
+ ports: well-known, registered
+ connection states
+ apache2 reinstallation
+ netstat

3. Basics of filtering with IPTables
+ iptables-save
+ at
+ iptables-restore
+ iptables-persist

4. Simple router
+ masquerade
+ dnsmasq
+ ethernet

5. Wi-fi Access Point
+ 802.11: versions, 5GHz/2.4GHz
+ forwarding again
+ dnsmasq again
+ hostapd

6. ???????

The prerequisites are being able to install Apache2 and set up two vhosts, something an earlier tutorial covered, but otherwise little to no computer knowledge required.

epoch1970
Posts: 4121
Joined: Thu May 05, 2016 9:33 am
Location: Paris, France

Re: Need advice - practical networking tutoring

Sat Jan 11, 2020 3:05 pm

I surely don't qualify as an educator but I'll say this:
- OSI presentation is good, but I wonder if your target audience would be receptive. Perhaps "layer-2 stays on the LAN, layer-3 and above is routable" would be sufficient?
- In the AP section, please mention the WiFi alliance decided bridging a client interface was forbidden. Should save everybody plenty of time in the future ;) (I've never seen an official statement as to why, but the potential for DoS seems obvious in this scenario).

Also, I could think of contemporary topics, I don't know if they are too "advanced" for the audience:
- Tunnelling (vpn, sdn). Perhaps you want to demystify these 2 buzzwords.
- Mesh networking (peer discovery, route election). Some consumer devices use mesh networking already, will be standard practice someday. (A talk by Juliusz Chroboczek, a professor, and creator of the Babel protocol)
"S'il n'y a pas de solution, c'est qu'il n'y a pas de problème." Les Shadoks, J. Rouxel

tpyo kingg
Posts: 664
Joined: Mon Apr 09, 2018 5:26 pm
Location: N. Finland

Re: Need advice - practical networking tutoring

Sun Jan 12, 2020 3:05 pm

Thanks. That was about the level of detail I was planning for the OSI model. It is good to have confirmation of that.

As for the bridging, can you point to any discussion or documentation from the WiFi alliance, or on the problem in general? Even unofficial notes would help as a reference. I was planning to have dnsmasq listening on the WiFi interface and use NAT instead of IPv6. My network is still on IPv4 until I rewrite a massive, convoluted, home-made router configuration.

incognitum
Posts: 398
Joined: Tue Oct 30, 2018 3:34 pm

Re: Need advice - practical networking tutoring

Tue Jan 14, 2020 12:54 pm

tpyo kingg wrote:
Sat Jan 11, 2020 6:36 am
3. Basics of filtering with IPTables
Would not teach legacy stuff like iptables, but go straight for nft instead.

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