Handbook:PPC64/Installation/Networking/pt-br
Detecção automática de rede
Talvez já esteja funcionando?
Se o sistema estiver conectado a uma rede Ethernet com um servidor DHCP, é muito provável que a configuração de rede já tenha sido feita automaticamente. Se for o caso, então os muitos comandos incluidos na mídia de instalação que dependem da rede tais como ssh, scp, ping, irssi, wget e links, entre outros, funcionarão imediatamente.
Usando DHCP
DHCP ("Dynamic Host Configuration Protocol" - Protocolo de Configuração Dinâmica de Host) torna possível obter informações de rede (endereço IP, máscara de rede, endereço de broadcast, servidores de nomes etc). Isso funciona apenas se houver um servidor DHCP na rede (ou se o provedor de Internet provê serviço DHCP). Para que uma interface de rede receba essa informação automaticamente, use dhcpcd:
DHCP requires that a server be running on the same Layer 2 (Ethernet) segment as the client requesting a lease. DHCP is often used on RFC1918 (private) networks, but is also used to acquire public IP information from ISPs.
Official Gentoo boot media runs dhcpcd automatically at startup. This behavior can be disabled by adding the
nodhcp
argument to the boot media kernel commandline.If it is not already running, dhcpcd can be started on enp1s0 with:
root #
dhcpcd eth0
Alguns administradores de rede requerem que o nome de host e o nome de domínio providos pelo servidor DHCP sejam usados pelo sistema. Nesse caso, use:
root #
dhcpcd -HD eth0
To stop dhcpcd, -x can be used:
root #
dhcpcd -x
sending signal Term to pid 10831 waiting for pid 10831 to exit
Dhcpcd usage
Testando a rede
A properly configured default route is a critical component of Internet connectivity, route configuration can be checked with:
root #
ip route
default via 192.168.0.1 dev enp1s0
If no default route is defined, Internet connectivity is unavailable, and additional configuration is required.
Basic internet connectivity can be confirmed with a ping:
root #
ping -c 3 1.1.1.1
It's helpful to start by pinging a known IP address instead of a hostname. This can isolate DNS issues from basic Internet connectivity issues.
Outbound HTTPS access and DNS resolution can be confirmed with:
root #
curl --location gentoo.org --output /dev/null
Se tudo funcionar, então o restante deste capítulo pode ser pulado para o próximo passo das instruções de instalação (Preparando os discos).
If curl reports an error, but Internet-bound pings work, DNS may need configuration.
If Internet connectivity has not been established, first interface information should be verified, then:
- net-setup can be used to assist in network configuration.
- Application specific configuration may be required.
- Manual network configuration can be attempted.
Determine os nomes das interfaces
If networking doesn't work out of the box, additional steps must be taken to enable Internet connectivity. Generally, the first step is to enumerate host network interfaces.
Como alternativa ao ifconfig, o comando ip pode ser usado para se determinar nomes de interfaces. O exemplo a seguir mostra a saída de ip addr (de um outro sistema, assim a informação mostrada é diferente do exemplo anterior):
The link argument can be used to display network interface links:
root #
ip link
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN mode DEFAULT group default qlen 1000 link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00 4: enp1s0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP mode DEFAULT group default qlen 1000 link/ether e8:40:f2:ac:25:7a brd ff:ff:ff:ff:ff:ff
The address argument can be used to query device address information:
root #
ip addr
2: eno1: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP group default qlen 1000 link/ether e8:40:f2:ac:25:7a brd ff:ff:ff:ff:ff:ff inet 10.0.20.77/22 brd 10.0.23.255 scope global eno1 valid_lft forever preferred_lft forever inet6 fe80::ea40:f2ff:feac:257a/64 scope link valid_lft forever preferred_lft forever
The output of this command contains information for each network interface on the system. Entries begin with the device index, followed by the device name: enp1s0.
Se não for mostrada nenhuma interface quando o comando padrão ifconfig for usado, tente usar o mesmo comando com a opção
-a
. Essa opção força o comando a mostrar todas as interfaces de rede detectadas pelo sistema independentemente de estarem em estado ativo ou inativo. Se o ifconfig -a não mostrar nenhum resultado então o hardware está com problema ou o driver da interface não foi carregado no kernel. Ambas as situações estão além do escopo deste manual. Contate o canal #gentoo (webchat) para suporte.No restante deste documento, o manual assumirá que a interface de rede é chamada eth0.
Como resultado de mudanças em favor de nomes de interfaces de rede predizíveis, o nome da interface do sistema pode ser bem diferente do antigo nome eth0. Mídias recentes de instalação pode mostrar nomes de interface de rede como eno0, ens1 ou enp5s0. Procure o nome da interface na saída do comando ifconfig que tem um endereço IP relacionado à rede local.
Optional: Application specific configuration
The following methods are not generally required, but may be helpful in situations where additional configuration is required for Internet connectivity.
Opcional: Configuração de proxy
Se a Internet é acessada através de um proxy, então é necessário entrar com as informações do proxy durante a instalação. É muito fácil definir um proxy: apenas defina uma variável que contém as informações do servidor proxy.
Certain text-mode web browsers such as links can also make use of environment variables that define web proxy settings; in particular for the HTTPS access it also will require the https_proxy environment variable to be defined. While Portage will be influenced without passing extra run time parameters during invocation, links will require proxy settings to be set.
Na maioria dos casos, é suficiente definir as variáveis usando o nome do servidor. Como exemplo, vamos assumir que o proxy é chamado proxy.gentoo.org e a porta é 8080.
The
#
symbol in the following commands is a comment. It has been added for clarity only and does not need to be typed when entering the commands.Para configurar um proxy HTTP (para tráfego HTTP e HTTPS):
root #
export http_proxy="http://proxy.gentoo.org:8080"
Se o proxy requer um nome de usuário e senha, use a seguinte sintaxe para a variável:
http://usuário:senha@proxy.gentoo.org:8080
Start links using the following parameters for proxy support:
user $
links -http-proxy ${http_proxy} -https-proxy ${https_proxy}
Para configurar um proxy FTP:
root #
export ftp_proxy="ftp://proxy.gentoo.org:8080"
Start links using the following parameter for a FTP proxy:
user $
links -ftp-proxy ${ftp_proxy}
Para configurar um proxy rsync:
root #
export RSYNC_PROXY="proxy.gentoo.org:8080"
Alternativa: Usando PPP
If PPPoE is required for Internet access, the Gentoo boot media includes the pppoe-setup script to simplify ppp configuration.
During setup, pppoe-setup will ask for:
- The name of the Ethernet interface connected to the ADSL modem.
- The PPPoE username and password.
- DNS server IPs.
- Whether or not a firewall is needed.
root #
pppoe-setup
root #
pppoe-start
In the event of failure, credentials in /etc/ppp/pap-secrets or /etc/ppp/chap-secrets should be verified. If credentials are correct, PPPoE Ethernet interface selection should be checked.
Alternativa: Usando PPTP
Se for necessário suporte a PPTP, use pptpclient, que é provido pelos CDs de instalação. Mas primeiro certifique-se que a configuração está correta. Edite /etc/ppp/pap-secrets ou /etc/ppp/chap-secrets de modo que contenha a combinação correta de usuário e senha:
Edit /etc/ppp/pap-secrets or /etc/ppp/chap-secrets so it contains the correct username/password combination:
root #
nano -w /etc/ppp/chap-secrets
Depois ajuste o /etc/ppp/options.pptp se necessário:
root #
nano -w /etc/ppp/options.pptp
Quando tudo pronto, execute pptp (juntamente com as opções que não puderam ser incluídas em options.pptp) para conectar ao servidor:
root #
pptp <endereço ipv4 do servidor>
Preparando para acesso sem fio
Do not use WEP unless it is the only option. WEP provides essentially no security over an open network.
O suporte ao comando iw pode ser específico da arquitetura. Se o comando não estiver disponível, verifique se o pacote net-wireless/iw está disponível para essa arquitetura. O comando iw estará indisponível até que o pacote net-wireless/iw esteja instalado.
Quando usar uma conexão sem fio (802.11), as configurações sem fio precisam ser feitas antes de qualquer coisa. Para ver as configurações atuais da placa usa-se o iw. Executando o iw deve aparecer algo como:
root #
iw dev wlp9s0 info
Interface wlp9s0 ifindex 3 wdev 0x1 addr 00:00:00:00:00:00 type managed wiphy 0 channel 11 (2462 MHz), width: 20 MHz (no HT), center1: 2462 MHz txpower 30.00 dBm
Para verificar a conexão atual:
root #
iw dev wlp9s0 link
Not connected.
ou
root #
iw dev wlp9s0 link
Connected to 00:00:00:00:00:00 (on wlp9s0) SSID: GentooNode freq: 2462 RX: 3279 bytes (25 packets) TX: 1049 bytes (7 packets) signal: -23 dBm tx bitrate: 1.0 MBit/s
Algumas interfaces sem fio podem ter o nome de interface tais como wlan0 ou ra0 em vez de eth0. Execute ip link para determinar o nome correto da interface.
Para a maioria dos usuários há apenas dois parâmetros necessários para a conexão, o ESSID (nome da rede sem fio) e, opcionalmente, a chave WEP.
- Primeiro, certifique-se que a interface está ativa:
root #
ip link set dev wlp9s0 up
- Para conexão com uma rede aberta de nome GentooNode:
root #
iw dev wlp9s0 connect -w GentooNode
- Para conexão usando uma chave WEP em hexadecimal, prefixe a chave com
d:
:
root #
iw dev wlp9s0 connect -w GentooNode key 0:d:1234123412341234abcd
- Para conexão usando uma chave WEP em ASCII:
root #
iw dev wlp9s0 connect -w GentooNode key 0:some-password
Se a rede sem fio estiver configurada com WPA ou WPA2, então é necessário usar o wpa_supplicant. Para mais informações sobre a configuração de rede sem fio no Gentoo Linux, por favor leia o capítulo sobre rede sem fio do Manual do Gentoo.
Verifique novamente a configuração da rede sem fio usando o iw dev wlp9s0 link. Uma vez que a rede sem fio estiver funcionando, prossiga com a configuração das opções de rede a nível de IP como descrita na próxima seção (Entendendo a terminologia de rede) ou use o comando net-setup como descrito anteriormente.
Configuração automática de rede
In cases where automatic network configuration is unsuccessful, the Gentoo boot media provides scripts to aid in network configuration. net-setup can be used to configure wireless network information and static IPs.
root #
net-setup eth0
O net-setup irá fazer algumas perguntas sobre o ambiente de rede. Quando terminar, a conexão de rede deve funcionar. Teste a conexão de rede como descrito anteriormente. Se os testes derem certo, parabéns! Pule o resto desta seção e continue com Preparando os discos.
Network status should be tested after any configuration steps are taken. In the event that configuration scripts do not work, manual network configuration is required.
Entendendo a terminologia de rede
If all of the above fails, the network must be configured manually. This is not particularly difficult, but should be done with consideration. This section serves to clarify terminology and introduce users to basic networking concepts pertaining to manually configuring an Internet connection.
Some CPE (Carrier Provided Equipment) combines the functions of a router, access point, modem, DHCP server, and DNS server into one unit. It's important to differentiate the functions of a device from the physical appliance.
Interfaces and addresses
Network interfaces are logical representations of network devices. An interface needs an address to communicate with other devices on the network. While only a single address is required, multiple addresses can be assigned to a single interface. This is especially useful for dual stack (IPv4 + IPv6) configurations.
For consistency, this primer will assume the interface enp1s0 will be using the address 192.168.0.2.
IP addresses can be set arbitrarily. As a result, it's possible for multiple devices to use the same IP address, resulting in an address conflict. Address conflicts should be avoided by using DHCP or SLAAC.
IPv6 typically uses StateLess Address AutoConfiguration (SLAAC) for address configuration. In most cases, manually setting IPv6 addresses is a bad practice. If a specific address suffix is preferred, interface identification tokens can be used.
Networks and CIDR
Once an address is chosen, how does a device know how to talk to other devices?
IP addresses are associated with networks. IP networks are contiguous logical ranges of addresses.
Classless Inter-Domain Routing or CIDR notation is used to distinguish network sizes.
- The CIDR value, often notated starting with a /, represents the size of the network.
- The formula 2 ^ (32 - CIDR) can be used to calculate network size.
- Once network size is calculated, usable node count must be reduced by 2.
- The first IP in a network is the Network address, and the last is typically the Broadcast address. These addresses are special and cannot be used by normal hosts.
The most common CIDR values are /24, and /32, representing 254 nodes and a single node respectively.
A CIDR of /24 is the de-facto default network size. This corresponds to a subnet mask of 255.255.255.0, where the last 8 bits are reserved for IP addresses for nodes on a network.
The notation: 192.168.0.2/24 can be interpreted as:
- The address 192.168.0.2
- On the network 192.168.0.0
- With a size of 254 (2 ^ (32 - 24) - 2)
- Usable IPs are in the range 192.168.0.1 - 192.168.0.254
- With a broadcast address of 192.168.0.255
- In most cases, the last address on a network is used as the broadcast address, but this can be changed.
Using this configuration, a device should be able to communicate with any host on the same network (192.168.0.0).
The Internet
Once a device is on a network, how does it know how to talk to devices on the Internet?
To communicate with devices outside of local networks, routing must be used. A router is simply a network device that forwards traffic for other devices. The term default route or gateway typically refers to whatever device on the current network is used for external network access.
It's a standard practice to make the gateway the first or last IP on a network.
If an Internet-connected router is available at 192.168.0.1, it can be used as the default route, granting Internet access.
To summarize:
- Interfaces must be configured with an address and network information, such as the CIDR value.
- Local network access is used to access a router on the same network.
- The default route is configured, so traffic destined for external networks is forwarded to the gateway, providing Internet access.
The Domain Name System
Remembering IPs is hard. The Domain Name System was created to allow mapping between Domain Names and IP addresses.
Linux systems use /etc/resolv.conf to define nameservers to be used for DNS resolution.
Many routers can also function as a DNS server, and using a local DNS server can augment privacy and speed up queries through caching.
Many ISPs run a DNS server that is generally advertised to the gateway over DHCP. Using a local DNS server tends to improve query latency, but most public DNS servers will return the same results, so server usage is largely based on preference.
Configuração manual de rede
Interface address configuration
When manually configuring IP addresses, the local network topology must be considered. IP addresses can be set arbitrarily; conflicts may cause network disruption.
To configure enp1s0 with the address 192.168.0.2 and CIDR /24:
root #
ip address add 192.168.0.2/24 dev enp1s0
The start of this command can be shortened to ip a.
Default route configuration
Configuring address and network information for an interface will configure link routes, allowing communication with that network segment:
root #
ip route
192.168.0.0/24 dev enp1s0 proto kernel scope link src 192.168.0.2
This command can be shortened to ip r.
The default route can be set to 192.168.0.1 with:
root #
ip route add default via 192.168.0.1
DNS configuration
Nameserver info is typically acquired using DHCP, but can be set manually by adding nameserver
entries to /etc/resolv.conf.
If dhcpcd is running, changes to /etc/resolv.conf will not persist. Status can be checked with
ps x | grep dhcpcd
.nano is included in Gentoo boot media and can be used to edit /etc/resolv.conf with:
root #
nano -w /etc/resolv.conf
Lines containing the keyword nameserver
followed by a DNS server IP address are queried in order of definition:
nameserver 9.9.9.9
nameserver 149.112.112.112
nameserver 1.1.1.1
nameserver 1.0.0.1
DNS status can be checked by pinging a domain name:
root #
ping -c 3 gentoo.org
Once connectivity has been verified, continue with Preparing the disks.