access control, see permissions
addgroup, 129
example, 134
address resolution, 204
address spoofing, 345
adduser, 129
example, 132, 134
administrator, see root user
Apache
base directory, 263
configuration directory, 263
configuration files, 263
log file, 265
apt
example, 307
ARP (protocol), 204
arp (command), 205
ARP (protocol), 348
basename
example, 117
Bash, 75, 106
built in, 78
comment (#), 107
execution, 110
for, 108, 114
if/then/else, 109, 115
options, 75
parameters, 75, 110, 116
PATH, 111
shebang (#!), 107
variables, 113
while, 116
wildcard, 75
cat, 86
cd, 79
-, 80
., 80
.., 80
~, 80
iptables
add a rule, 293
chains, 282
change policy, 299
default policy, 286
delete rules, 294
FORWARD chain, 283
INPUT chain, 283
list rules, 294
OUTPUT chain, 283
POSTROUTING chain, 283
PREROUTING chain, 283
rules, 286
SPI, 302
chgrp, 130
child process, 99
chmod, 130
example, 137, 139
chown, 130
example, 138
client, 99
client/server, 97
cmp
example, 182
connection, 98
list, 205
cp, 82
example, 162
cryptography
classical, 184
cut
example, 163
Cygwin, 20
date
example, 117
decryption, 165
deluser
example, 132
dhclient, 310
DHCP, 306
client, 306
lease, 307
server, 306
dhcpd, 309
diff
example, 165
dig, 201
digital signature, 177
directory
absolute path, 79
changing, see cd
current, 74, 79, 80
home, 79, 80, 123
previous, 80
relative path, 79
root, 78
separator, 78
up a level, 80
DNS, see domain name servce
domain name service, 201
drivers, 240
echo, 90
example, 112, 168
emacs, 92
encryption, 165
ethtool, 195
file
example, 117
files
copying, see cp
deleting, see rm
editing, 91
empty, 90
end, 87
extensions, 83
following, 88
hidden, 85
moving, see mv
renaming, see mv
size, 84
start, 87
viewing, 86, 87
FileZilla, 31
Firefox, 66
firewall, 275, see also iptables
flooding, 360
fork(), 392
forwarding, 223, 227
gateway, see router
gedit, 92
git, 316
add, 320
clone, 318
commit, 320
config, 319
example, 185
pull, 321
push, 320
GNU, 19
groups
adding new, 129
adding user, 129
changing, 130
groups
example, 139
guest OS, 21
hash, 166
head, 87
-n, 88
help, see also man
history, 92
host, 201
host name, 74
host OS, 21
HTTP, 100
status codes, 436
ICMP, 199
id
example, 132
ifconfig, 192
info, 78
internet, 223
ip_forward, 227
iperf, 214
iptables, 275, 282
example, 345, 356
filter table, 282
mangle table, 282
nat table, 282
iptraf, 213, 367
iw, 408
iwconfig, 408
kernel, see Linux kernel
less, 87, 266
Linux, 17
distributions, 17
release, 19
Ubuntu, 17
Linux kernel, 19
loopback interface, 192
ls, 75, 80
-1, 89
-R, 138
-a, 76
-h, 85
-l, 76, 84
example, 112, 126
lynx, 100
man, 77
mkdir, 81
mktemp
example, 117
mode of operation, 168
modes, see permissions
mv, 83
nano, 91
nc, 212
netcat, see nc
netstat, 205
nslookup, 201
NTP, 375
ntpdate, 377
ntpdc, 377
OpenSSL, 160
dgst, 166, 177
enc, 165
genpkey, 172, 179
list-cipher-algorithms, 164
list-message-digest-algorithms, 166
padding, 168
pkey, 173
pkeyparam, 179
pkeyutl, 177, 182
rand, 164, 169
smime, 177
speed, 183
packet capture, 244
parent process, 99
passwd, 125, 130
password
example, 134
storage, 143
passwords
brute force, 150
hashed, 147
salt, 153, 165
permissions, 125
changing, 130
changing owners, 130
execute directory (x), 125
execute file (x), 125
group owner (g), 125
other users (u), 126
read directory (r), 125
read file (r), 125
user owner (u), 125
write directory (w), 125
write file (w), 125
ping, 199
example, 348, 352
ping flooding attack, 360
pipes, 89
port, 98
list of numbers, 435
well-known, 99
process
child, 99
client, 99
parent, 99
server, 99
prompt, 74
protocol number, 98
protocol numbers, 436
public key cryptography, 171
PuTTY, 31, 69
pwd, 79
pycipher, 184
Python, 184
rainbow table, see also passwords
random numbers
/dev/random, 163
/dev/urandom, 163
$RANDOM, 162
read, 116
redirection, 90
output, 90
reverse DNS, 201
rfkill, 414
rm, 82
rmdir, 81
root user, see users, root
round trip time, 199
route, 203
add, 229
delete, 229
router, 223
default, 224
routing, 223
routing cache, 203
routing table, 203, 224
view, 203, 229
RSA, 171
salt, see passwords, salt
script, see Bash
Secure shell, seessh101
sed
example, 167
server, 99
sha256cum, 167
shell, see Bash
socket, 389
datagram, 389
stream, 389
socket API
accept(), 392
connect(), 392
read(), 392
write(), 392
SOCKS, 65
source code, 8
spoofing, see address spoofing
ssh, 101
standard error, 77
standard input, 77
standard output, 77
stat
example, 117
stateful packet inspection, 301
statistics
TCP/IP, 205
su, 129
example, 135
sudo, 129
sudoers, 132
super user, see root user
sysctl, 364
sysctl, 227
systemctl
example, 309
tail, 87, 266
-f, 88
-n, 88
tar
example, 117
tc, 217, 364
tcpdump, 244
example, 348, 352
telnet, seessh101
test, 109
example, 115
touch, 90
tr
example, 117
tracepath, 200
traceroute, see tracepath
tunnel, 65
Ubuntu, see Linux
Unix, 17, see also Linux
username, see users
users
adding new, 129
changing passwords, 130
deleting, 132
ID, 123
root, 123
switching, 129
user name, 123
VBoxManage, 28
version control, 316
vi, 91
virtnet, 27
download, 32
password, 56
requirements, 31
topology, 32
virtual network, 26
virtualisation, 21
hardware, 31
wc
example, 168
well-known port, 99
wget, 101
Windows Subsystem for Linux, 20
WinSCP, 31
wireless
managed mode, 407
monitor mode, 407
Wireshark, 244
filters, 249
statistics, 249
xxd
example, 163–165, 168