Differenze tra le versioni di "Net-HOWTO"
| Riga 112: | Riga 112: | ||
==Setup LAN Interfaces== | ==Setup LAN Interfaces== | ||
===Predictable Network Interface Names=== | ===Predictable Network Interface Names=== | ||
| − | Starting with v197 systemd assign fixed and predictable network interface names for all local network devices instead of the traditional ''eth0, ''eth1'', ''wlan0'' which may change after a reboot post kernel update. This feature simplify the system management and fix potential security implications e.g., changing firewall rules. | + | Starting with v197 systemd assign fixed and predictable network interface names for all local network devices instead of the traditional ''eth0'', ''eth1'', ''wlan0'' which may change after a reboot post kernel update. This feature simplify the system management and fix potential security implications e.g., changing firewall rules. |
These names are based on hardware firmware/topology/location information and they stay fixed even if hardware is added or removed. | These names are based on hardware firmware/topology/location information and they stay fixed even if hardware is added or removed. | ||
Versione delle 09:56, 15 dic 2024
Introduction
This is the first release of the GOLEM Network Howto, this document aims to be a sort of unofficial update of the Linux Networking Howto.
General Information about Networking
Sources of non-linux-specific network information
If you are looking for general TCP/IP networking information, here you can find some resources:
IPv4 Addresses
Internet Protocol v4 Addresses are composed of 4 bytes (32 bit), each byte is converted to a decimal number (0-255) and bytes are separated by a . (dot), for this reason IPv4 addresses are limits to near 4 billions (232). Usually every network interface has its own IP address in a format like this: 192.168.0.5
Subnetting
Addresses in a network have some digits in common, that part is called the network portion of the address, the remaining numbers are called the host portion.
For example:
----------------- ---------------
Host Address 192.168.0.23
Network Portion 192.168.0.
Host portion .23
----------------- ---------------
Network Address 192.168.0.0
Broadcast Address 192.168.0.255
----------------- ---------------
Subnetting is a way to subdivide an TCP/IP network. The Classless Inter-Domain Routing (CIDR) is the current method for defining subnet, the IP address is followed by a prefix number between 0 and 32 that shows how many bits represent the network.
192.168.0.23/24 => network 192.168.0.0 - 192.168.0.255 192.168.0.23/16 => network 192.168.0.0 - 192.168.255.255
This method replace the obsolete classful network addressing architecture.
The maximum number of addresses of a network may be calculated as 232 − prefix number
| CIDR | Classful network mask | Number of Hosts | Typical use |
|---|---|---|---|
| /8 | 255.0.0.0 | 16777214 = 224 - 2 | Largest IANA block allocation |
| /9 | 255.128.0.0 | 8388608 = 223 | |
| /10 | 255.192.0.0 | 4194304 = 222 | |
| /11 | 255.224.0.0 | 2097152 = 221 | |
| /12 | 255.240.0.0 | 1048576 = 220 | |
| /13 | 255.248.0.0 | 524288 = 219 | |
| /14 | 255.252.0.0 | 262144 = 218 | |
| /15 | 255.254.0.0 | 131072 = 217 | |
| /16 | 255.255.0.0 | 65536 = 216 | |
| /17 | 255.255.128.0 | 32768 = 215 | ISP / large business |
| /18 | 255.255.192.0 | 16384 = 214 | ISP / large business |
| /19 | 255.255.224.0 | 8192 = 213 | ISP / large business |
| /20 | 255.255.240.0 | 4096 = 212 | Small ISP / large business |
| /21 | 255.255.248.0 | 2048 = 211 | Small ISP / large business |
| /22 | 255.255.252.0 | 1024 = 210 | |
| /23 | 255.255.254.0 | 512 = 29 | |
| /24 | 255.255.255.0 | 256 = 28 | Large LAN |
| /25 | 255.255.255.128 | 128 = 27 | Large LAN |
| /26 | 255.255.255.192 | 64 = 26 | Small LAN |
| /27 | 255.255.255.224 | 32 = 25 | Small LAN |
| /28 | 255.255.255.240 | 16 = 24 | Small LAN |
| /29 | 255.255.255.248 | 8 = 2³ | The smallest multi-host network |
| /30 | 255.255.255.252 | 4 = 2² | Point-to-point links (glue network) |
| /31 | 255.255.255.254 | 2 = 21 | Point-to-point network (RFC 3021) |
| /32 | 255.255.255.255 | 1 = 20 | Single host |
Traffic between subnets is guaranteed by routers.
Network Configuration
Driver
Modern Linux distributions already include driver for most of LAN and WiFi devices. Otherwise try to upgrade your OS or compile and install a newer kernel.
Network tools
iproute2: IP Routing Utilities
nftables: Linux kernel packet control tool (firewall)
iputils: arping, clockdiff, ping, tracepath
Legacy tools
net-tools: configuration tools for Linux networking (arp, ifconfig, ipmaddr, iptunnel, mii-tool, nameif, netstat, plipconfig, rarp, route, slattach)
iptables: Linux kernel packet control tool (firewall)
Network Application Programs
Most common network application programs are collected in the inetutils package: dnsdomainname, ftp, ftpd, hostname, ifconfig, ping, rcp, rlogin, rlogind, rsh, rshd, talk, talkd, telnet, telnetd, whois
Setup LAN Interfaces
Predictable Network Interface Names
Starting with v197 systemd assign fixed and predictable network interface names for all local network devices instead of the traditional eth0, eth1, wlan0 which may change after a reboot post kernel update. This feature simplify the system management and fix potential security implications e.g., changing firewall rules.
These names are based on hardware firmware/topology/location information and they stay fixed even if hardware is added or removed.
Prefix Description en Ethernet ib InfiniBand sl Serial line IP (slip) wl Wireless local area network (WLAN) ww Wireless wide area network (WWAN)
eth0 could be renamed enp6s0: en (ethernet) + p6 (bus 6) + s0 (slot 0)
Manual managing
The following commands activates the enp6s0 interface with the IP 192.168.0.2, for the subnet 192.168.0.1-255, using the router-gateway 192.168.0.1
# ip addr add 192.168.0.2/24 dev enp6s0 # ip route add default via 192.168.0.1
For a non fixed IP address in a LAN with a DHCP server just run
# dhcpcd enp6s0
Useful commands
Show devices IP addresses
# ip addr
Show information of a specific interface
# ip addr show enp6s0
Add IP addresses on a device
# ip addr add 192.0.2.10/24 dev enp6s0
Delete a device IP
# ip addr delete 192.0.2.10/24 dev enp6s0
Enabling the interface enp6s0 without specifying an IP
# ip link set dev enp6s0 up
Disabling the interface enp6s0
# ip link set dev enp6s0 down
Set 192.168.0.2 as default gateway for the host
# ip route add default via 192.0.2.1
Add the gateway 192.168.0.1 route for the interfaces enp2s0 10.0.2.0
# ip route add 10.0.2.1/24 via 192.168.0.1 dev enp2s0
Remove the gateway 192.168.0.1 route for the interfaces enp2s0 10.0.2.0
# ip route del 10.0.2.0/24 via 192.168.0.1 dev enp2s0
Show the routing table
# ip route show
configuration files
Systemd-networkd
systemd-networkd è un demone, parte di systemd, che gestisce la configurazione della rete.
Per prima cosa sarà necessario abilitare il servizio
# systemctl enable --now systemd-networkd.service # systemctl enable --now systemd-resolved.service # ln -rsf /run/systemd/resolve/stub-resolv.conf /etc/resolv.conf
DHCP
/etc/systemd/network/20-wired.network
[Match] Name=enp1s0 [Network] DHCP=yes
IP statico
/etc/systemd/network/20-wired.network
[Match] Name=enp1s0 [Network] Address=10.1.10.9/24 Gateway=10.1.10.1 DNS=10.1.10.1
Wireless adapter
Per potersi connettere a connessioni WIFI è necessario installare e configurare un'ulteriore applicazione dedicata come iwd o wpa_supplicant per l'autenticazione alla rete.
/etc/systemd/network/25-wireless.network
[Match] Name=wlp2s0 [Network] DHCP=yes IgnoreCarrierLoss=3s
Rinominare l'interfaccia di rete
Invece che impostare una regola su udev è possibile usare un file di testo .link nel seguente modo
/etc/systemd/network/10-ethusb0.link
[Match] MACAddress=12:34:56:78:90:ab [Link] Description=USB to Ethernet Adapter Name=ethusb0
https://wiki.golem.linux.it/Appunti_Arch_Linux#Networking