Review of cat5
why cat 5? what is cat6? cat4? cat 3?
Why is it also called twisted pair?
how many pairs? why a pair, and why twisted?
full duplex vs half duplex: which is which? examples?
wiring notes: 1/2, 3/6 why?
hubs vs. switches vs. managed switches
layer 2 managed gigabit switch
gateways: different media routers: same media
MAC address: 0a:1e:df:e1:58:16
first three pairs are the OUI
MAC stands for machine access control
IP masquerading: 254x254x254x254 still not enough addresses
hexadecimal: 2^4 = 16 so 0-9, a,b,c,d,e,f
subnet mask: 255.255.255.0 what does this mean? why is HPA 255.255.0.0? why was it 255.0.0.0?
which is better? why?
router: 192.168.1.1 (does this exist?) what is a router/gateway? what is the difference?
DNS: what does this mean? can your computer work without it? how can you diagnose a dns issue?
TCP/IP as messages: TCP is the message, IP is the envelope
packets: header (destination), payload (message), footer (error correction) <more on this later with checksums>
Homework: read TCP/IP article on wikipedia, look up all terms
Homework next : cli share
cloud: all IPs (except for 10.x.y.z, 172.16.x.y, and 192.168.1.x) [this is called IP masquerading]
HPA: 10. x.y.z
Your internal network will be 192.168.1.x
routers vs. gateways
Airport extreme setup:
Make a new location called "dhcp wired"
make only ethernet active, with dhcp network numbers
connect to the reset airport base station on the LAN side (WAN side has a globe on it)
What is LAN and WAN again?
Configure your base station to do DHCP and NAT, with internal address starting with 192.168.1.x
Give your router a fixed address in the forma 10.14.251.x, with the list on the board
Your router external will be 10.14.251.x (numbers on board)
Your internal numbers will be 192.168.1.x (DHCP cannot be turned off on airport extreme routers-more on this next)
map out the path an incoming packet would take
packet dialog: ask (request), answer (response), check to see if you got it (TCP only, not UDP-why?)
can you browse the web?
what dns are you using?
can outside folks see your web page?
what web page?
I have a web page?
who the heck is "apache" and why is he in my computer?
(USERNAME is your short login name)
then paste this part in:
Options Indexes Multiviews
AllowOverride AuthConfig Limit
Allow from all
to start your web server, do this:
sudo apachectl start
what port is my web page on?
take a step back: setup your computer to share over the web: http, afp and ssh
find the ports for each of these (don't just check the little boxes)
Next: port scans-computer burglars...
also--hacker routers: dd-wrt