network20250315.txt

(C) David Vajda
20250315
Network training

NUL - Null
SOH - Start Of Heading
SOT - Start Of Text
ETX - End of Text
EOT - End of Transmission
ETB - End of Transmission Block

Nicht sass:

ETX, ETX, ETX, ETX, ETX, ETX
STX, STX, STX, STX, STX, STX

Start Of Text, End Of Text
Start Of Text, End Of Text

CR - Carriage Return
BEL - Bell
DEL - Delete
CAN - Cancel
HT - Horizontal Tab
VT - Vertical Tab
LF - Line Fead
FF - Form Feed
DC1 - Device Control 1
DC2, DC3, DC4
SI - Shift In
SO - Shift Out
ACK - Acknowledge
NAK - Negative Acknowlegement


ACK/NAK Protokoll
X-ON/X-OFF Protokoll

X-ON: Shift In - SI - Strg-Q
X-OFF: Shift-Off - SO - Strg-S

Dataflow Controll

CCITT-1

RS-232

MAX-232
R1OUT
R2OUT
R1IN
R2IN
T1OUT
T2OUT
T1IN
T2IN

Data Terminal - Datenendgeraet - Flughafen - terminal - ende, bank: terminal  - Automated Teller Machine
Datenuebertragungsgeraet - Modem

TxD - Transmit Data
RxD - Recieve Data
GND - Ground

Ready - Bereit
Request - Aufforderung
Clear -
Acknowledge - Bestaetigung

lernen: clear - erlaubnis

ready - bereit machen
clear - erlaubnsi

ready - bereit
clear - erlaubnis

ready - bereit
clear - erlaubnis

erlaubnis erlaubis ich erlaube, ich erlaube, ...

Data Set Ready
Data Terminal Ready
RTS - Request To Send
CTS - Clear To Send

jetzt kommt neues

ports:
http 80
https 443
ssh 21
smtp 25

...

15 netstat
15 netstat
15 netstat
15 netstat
15 netstat
15 netstat

20 ftp
20 ftp
20 ftp
20 ftp

20 ftp
21 ssh
25 smtp

20 ftp
21 ssh
25 smtp

20 ftp
21 ssh
25 smtp

20 ftp
21 ssh
25 smtp

falsch 21, ssh!


22 ssh
22 ssh/dropbear
22 ssh/dropbear
22 ssh/dropbear

2 mal die 2 ssh
2 mal die 2 ssh

23 telnet
23 telnet
23 telnet

15 netstat
23 telnet

15 netstat
23 telnet

20 ftp
22 ssh
23 telnet
25 smtp

20 ftp
22 ssh
23 telnet
25 smtp

20 ftp
22 ssh
23 telnet
25 smtp

20 ftp
22 ssh
23 telnet
25 smtp


53 dns
53 dns
53 dns
53 dns

110 pop3
110 wie polizei pop3
110 wie polizei pop3
110 wie polizei pop3


587 SMTP
587 SMTP

53 DNS
587 SMTP

587 587 587 587

53

15
20
22
23
25
53
80
110
587

15 netstat
20 ftp
22 ssh
23 telnet
25 ftp
53 dns
80 http
110 pop3
587 smtp

143 imap
143 imap
143 imap
143 imap

110 pop3
143 imap

110 polizei pop3
143 + 33 = imap

110 polizei pop3
143 + 33 = imap

110 polizei pop3
143 + 33 = imap

15 netstat
20 ftp
22 ssh
25 smtp
53 dns
80 http
110 pop
143 imap
587 smtp

nfs?

110 pop3 polizei
143 imap
110 pop3 polizei
143 imap

587 587 587 587

jetzt kommen die records

DNS: RR - Resource Record
Resource Record
Resource Record
Resource Record

A
AAAA
A
AAAA
A
AAAA
A
AAAA

A address record
A address record
A address record

A
AAAA
A
AAAA
A
AAAA
A
AAAA

A address record

CNAME
CNAME
CNAME
CNAME
CNAME
CNAME
CNAME

CNAME - Canonical Name Record

kanonisch: richtschnur

CNAME
CNAME
CNAME
CNAME - Canonical name record
canonical name record
canonical name record
canonical name record

kanonisch - richtschnur
kanonisch - richtschnur

A
AAAA
CNAME

A
AAAA
CNAME

A
AAAA
CNAME

MX
MX
MX
MX

A
AAAA
CNAME
MX

MX Mail eXchange Record
MX Mail eXchange Record
MX Mail eXchange Record

PTR Pointer Record
PTR Pointer Record
PTR Pointer Record

A
AAAA
CNAME
MX
PTR

A
AAAA
CNAME
MX
PTR

A
AAAA
CNAME
MX
PTR

TXT
TXT
TXT

TXT Text Record
TXT Text Record


A
AAAA
CNAME
MX
PTR
TXT

A
AAAA
CNAME
MX
PTR
TXT

pruefsummen:
    fletcher's checksum
    fletcher's checksum
    fletcher's checksum
    fletcher's checksum
    fletcher's checksum

    adler-32
    adler-32
    adler-32
    adler-32

    fletcher's checksum
    adler-32
    fletcher's checksum
    adler-32
    fletcher's checksum
    adler-32
    fletcher's checksum

    CRC
    CRC
    CRC
    CRC
    CRC - zyklische redundanzpruefung
    CRC - zyklische redundanzpruefung
    CRC - zyklische redundanzpruefung

    fletcher's checksum
    adler-32
    CRC

    fletcher's checksum
    adler-32
    CRC zyklische redundanzpruefung

    fletcher's checksum
    adler-32
    CRC - zyklische redundanzpruefung

    Paritaet
    Quersumme

    Paritaet
    Quersumme

    Paritaet
    Quersumme

    fletcher's checksum
    adler-32
    CRC - zyklische redundanzpruefung
    Paritaet
    Quersumme := (x(n-1) + ... x1 + x0)/n


    krypto
    password

    kryptische hashfunktion
    passwort hashfunktion

    kryptische hashfunktion
    password hashfunktion

    md2, md4, md5
    md2, md4, md5
    md2, md4, md5
    SHA
    SHA - Secure Hash Algorithm
    SHA - Secure Hash Algorithm
    SHA - Secure Hash Algorithm

    Fletcher's Checksum
    Adler-32
    CRC - zyklische Redundanzpruefung
    Quersumme
    Paritaet
    Verschluesselungs-Hash
        MD2, MD4, MD5
        SHA - Secure Hash Algorithm

    Tiger HAVAL Whirlpool
    Tiger HAVAL Whirlpool
    Tiger HAVAL Whirlpool
    Tiger HAVAL Whirlpool

    RIPEMD-160
    RIPEMD-160

    RIP - wie Rest in Peace

    RIPEMD-160

    Tiger HAVAL Whirlpool

    LM-Hash (password)
    LM-Hash
    LM-Hash

    Bcrypt
    Scrypt

    Bcrypt
    Scrypt

    Bcrypt
    Scrypt

    Argon2

    Argon2

    LM-Hash
    Bcrypt
    Scrypt
    Argon2

    LM-Hash
    Bcrypt
    Scrypt
    Argon2

    MD2, MD4, MD5
    SHA
    tiger HAVAL Whirlpool
    MD2, MD4, MD5
    SHA
    tiger HAVAL whirlpool

    LM-hash
    Bcrypt
    Scrypt
    Argon2

    IBAN Modulo 97
    IBAN Modulo 97
    IBAN Modulo 97
    IBAN Modulo 97

    EAN
    IBAN
    EAN
    IBAN
    EAN
    IBAN

    EAN - Strichcode
    EAN - strichcode

    IBAN - modulo 97

    ISBN

    IBAN EAN ISBN
    IBAN EAN ISBN
    IBAN EAN ISBN
    IBAN EAN ISBN
    IBAN EAN ISBN

TCP
    Source Port
    Destination Port

    Source Port
    Destination Port
    Source Port
    Destination Port
    Source Port
    Destination Port

    Source Port (2 Byte)
    Source Port (2 Byte)
    Source Port (2 Byte)
    Destination Port (2 Byte)
    Destination Port (2 Byte)

    Source Port (2 Byte)
    Destination Port (2 Byte)

    Source Port (2 Byte)
    Destination Port (2 Byte)

    Sequence Number
    Sequence Number
    Sequence Number

    Acknowledgement Number
    Acknowledgement Number
    Acknowledgement Number

    Sequnce Number
    Acknowdgement Number

    Source Port
    Destination Port
    Sequence Number
    Acknowledgement Number

    Source Port
    Destination Port
    Sequence Number
    Acknowledgement Number

    2 Byte, 2 Byte, 4 Byte, 4 Byte
    2 Byte, 2 Byte, 4 Byte, 4 Byte

    2 Byte, 2 Byte, 4 Byte, 4 Byte

    Source Port (2 Byte)
    Destination Port (2 Byte)
    Sequence Number (4 Byte)
    Acknowledgement Number (4 Byte)

    Data Offset
    Reserved

    Data Offset
    Reserved

    Data Offset
    Reserved
    Controll Flags

    Data Offset
    Reserved
    Controll Flags

    Data Offset
    Reserved
    Controll Flags

    Source Port
    Destination Port
    Sequence Number
    Acknowledgement Number
    Data Offset
    Reserved
    Controll Flags

    Recieve Window
    Checksum
    Urgent Pointer
    Options


    ACK-Number
    ACK-Number

    Recieve window
    Checksum
    urgent pointer
    options

    recieve window
    checksum
    urgend pointer
    options

IP
    Quell-IP-Addresse
    Ziel-IP-Addresse

    Quell-IP-Addresse
    Ziel-IP Addresse

    IHL - wie DHL nur I in IP
    IHL - wie DHL nur I in IP
    IHL - wie DHL nur I in IP
    IHL - wie DHL nur I in IP

    DSCP DSCP DSCP DSCP

    scp - secure shell copy - linux mit Dave davorr
    DSCP - scp mit d wie dave davor
    DSCP - scp mit d wie dave davor

    IHL - wie DHL - Nur i wie in IP und wie in IHP nur ohne P wie IP
    IHL - wie DHL und IHP
    IHL - wie DHL und IHP
    DSCP - Dave und scp
    DSCP - Dave und scp
    ECN - wie EAN nur C wie in TCP
    ECN - wie EAN nur c wie in TCP

    IHL DSCP ECN
    IHL DSCP ECN
    IHL DSCP ECN
    IHL DSCP ECN

    Gesamtlaenge
    identifikation
    flags

    gesamtlaenge
    identifikation
    flags

    fragment offset
    fragment offse
    fragment offset
    ttl

    ttl
    ttl - time to live - wie in TTL 74xx

    IHL DSCP ECN TTL
    IHL DSCP ECN TTL

    flags
    fragment offset
    flags
    fragment offset

    protokoll
    header-pruefsumme

    protokoll: TCP/UDP - transport layer - siehe Fritz!-Box
    protokoll: TCP/UDP - Transport Layer - siehe Fritz!-Box

    NAT - Network Address Translation
    NAT - Network Address Translation

    quell-ip-addresse
    ziel-ip-addresse
    IHL DSCP ECN TTL

    quell-port
    ziel-port
    sequence number
    acknowledgement number
    reserved
    flags
    data offset
    ...

    PGP

    IDEA wie IKEA
    IDEA IDEA IDEA
    3DES 3DES 3DES

    IDEA 3DES
    IDEA 3DES
    IDEA 3DES

    CAST5 CAST5 CAST5

    IDEA 3DES CAST5
    IDEA 3DES CAST5
    IDEA 3DES CAST5

    BLOWFISH
    BLOWFISH
    BLOWFISH
    BLOWFISH

    IDEA 3DES CAST5 BLOWFISH
    IDEA 3DES CAST5 BLOWFISH
    IDEA 3DES CAST5 BLOWFISH
    AES
    AES
    AES
    AES
    AES192
    AES192
    AES192
    AES192
    AES256
    AES256
    AES256

    AES AES192 AES256
    AES AES192 AES256

    IDEA 3DES CAST5 BLOWFISH AES AES192 AES256

    IDEA 3DES CAST5 BLOWFISH AES AES192 AES256

    TWOFISH TWOFISH TWOFISH TWOFISH
    BLOWFISH TWOFISH BLOWFISH TWOFISH
    BLOWFISH TWOFISH BLOWFISH TWOFISH

    CAMELLIA CAMELLIA CAMELLIA CAMELLIA
    CAMELLIA128 CAMELLIA192 CAMELLIA256

    CAMELLIA128 CAMELLIA192 CAMELLIA256

    IDEA 3DES CAST5 BLOWFISH
    AES AES192 AES256 TWOFISH
    CAMELLIA128 CAMELLIA192 CAMELLIA256

    Pruefsummen
        MD5
        SHA1
        RIPEMD160
        SHA2

        MD5
        SHA1
        SHA2

    jetzt kommt iptables

    ACCEPT DROP FORWARD POSTROUTING PREROUTING -j

    -A INPUT OUTPUT

    --dport --sport

    -s Source -d Destination

    -i input Network interface
    -o Output Network interface

    Port Forwarding
    NAT Network Address Translation

    ifconfig lo:2 127.0.0.3 NETMASK 255.0.0.0 UP


    Tabellen Regelketten
    Tabellen Regelketten
    Tabellen Regelketten

    Chains:
        PREROUTING
        INPUT
        FORWARDING
        OUTPUT
        POSTROUTING

    Chains:
        PREROUTING
        INPUT
        FORWARDING
        OUTPUT
        POSTROUTING

    Chains:
        PREROUTING
        INPUT
        FORWARDING
        OUTPUT
        POSTROUTING

    Table:
        filter nat mangle
        filter nat mangle raw
        filter nat mangle raw
        filter nat mangle raw
        filter nat mangle raw

    PREROUTING
    INPUT
    FORWARDING
    OUTPUT
    POSTROUTING

    filter nat mangle raw

    -t TABLE
    -A CHAIN

    -t TABLE
    -A CHAIN

    -t TABLE
    -A CHAIN

    -t TABLE
    -A CHAIN

    -i Device
    -o Device
    -i Device
    -o Device

    -s IP-ADDR
    -d IP-ADDR

    -p PROTOCOLL TCP/UDP/ICMP

    ICMP ICMP ICMP ICMP ICMP

    TCP UDP ICMP
    TCP UDP ICMP
    TCP UDP ICMP

    -A CHAIN
    -t TABLE
    -i device
    -o device
    -s IP-Addr
    -d IP-Addr
    -p PROTOCOLL
    --source-port
    --destination-port

    --source-port
    --destination-port


    filter nat mangle raw
    filter nat mangle raw

    -j ACTION
    -j ACTION

    ACCEPT DROP REJECT
    ACCEPT DROP REJECT

    ip iptables interfaces netstat ifconfig
    ip iptables interfaces netstat ifconfig
    ip iptables interfaces netstat ifconfig

    /etc/hostname
    hostname

    ip ifconfig
    ip ifconfig
    ip ifconfig dig
    dig dns
    ip ifconfig dig
    dig dns
    ip ifconfig dig
    dig dns
    ip ifconfig dig
    dig dns
    ip ifconfig dig
    dig dns record
    ip ifconfig dig
    dig dns record
    nslookup
    netstat
    nslookup
    netstat nslookup
    netstat nslookup
    dig dns record
    ip ifconfig dig nslookup netstat
    ip ifconfig dig nslookup netstat
    traceroute
    traceroute
    netstat tracerout nslookup
    netstat traceroot nslookup
    host
    hostname
    host
    hostnam
    nslookup netstat traceroot
    host hostname
    ping route traceroute
    ping route traceroute
    ping route traceroot

    ip ifconfig dig nslookup netstat traceroot root ping
    hostname host

    whois
    whois
    whois

    iftop
    iftop - monitoring
    iftop - monitoring