Core OS Index

2.3. Network

Operation of the network can be handle with init scripts;

/etc/rc.d/iptables
Configure iptables, start option loads set of rules from file /etc/iptables/name.v4, open option allows everything to outside and blocks everything from outside, stop will block and log everything.
/etc/rc.d/net
Configure Ethernet interface with static or dynamic (dhcp) IP, set default route and add default gateway.
/etc/rc.d/wlan
Configure Wireless interface, launch wpa_supplicant to handle wireless authenticationand dynamic (dhcp) connection to router and add as default gateway.

Choose wireless or net as connection to outside world and configure /etc/rc.conf to run at startup, example connecting using wireless interface;

        #
        # /etc/rc.conf: system configuration
        #

        FONT=default
        KEYMAP=dvorak
        TIMEZONE="Europe/Lisbon"
        HOSTNAME=c9
        SYSLOG=sysklogd
        SERVICES=(lo iptables wlan crond)

        # End of file
        

If is first boot after install configure iptables and one of above described scripts then proceed to update system.

2.3.1. Resolver

This example will use Chaos Computer Club server, edit /etc/resolv.conf and make it immutable;

        # /etc/resolv.conf.head can replace this line
        nameserver 213.73.91.35
        # /etc/resolv.conf.tail can replace this line
        
        # chattr +i /etc/resolv.conf
        

2.3.2. Static IP

Current example of /etc/rc.d/net;

        Address:   192.168.0.1           11000000.10101000.00000000 .00000001
        Netmask:   255.255.255.0 = 24    11111111.11111111.11111111 .00000000
        Wildcard:  0.0.0.255             00000000.00000000.00000000 .11111111
        =>
        Network:   192.168.0.0/24        11000000.10101000.00000000 .00000000 (Class C)
        Broadcast: 192.168.0.255         11000000.10101000.00000000 .11111111
        HostMin:   192.168.0.1           11000000.10101000.00000000 .00000001
        HostMax:   192.168.0.254         11000000.10101000.00000000 .11111110
        Hosts/Net: 254                   (Private Internet)
        

Other IP class that can used for private network;

        Address:   10.0.0.1              00001010.00000000.00000000 .00000001
        Netmask:   255.255.255.0 = 24    11111111.11111111.11111111 .00000000
        Wildcard:  0.0.0.255             00000000.00000000.00000000 .11111111
        =>
        Network:   10.0.0.0/24           00001010.00000000.00000000 .00000000 (Class A)
        Broadcast: 10.0.0.255            00001010.00000000.00000000 .11111111
        HostMin:   10.0.0.1              00001010.00000000.00000000 .00000001
        HostMax:   10.0.0.254            00001010.00000000.00000000 .11111110
        Hosts/Net: 254                   (Private Internet)
        

Manual configuring like net script;

        # DEV=enp8s0
        # ADDR=192.168.1.9
        # MASK=24
        # GW=192.168.1.254
        
        # ip addr flush dev ${DEV}
        # ip route flush dev ${DEV}
        # ip addr add ${ADDR}/${MASK} dev ${DEV} broadcast +
        # ip link set ${DEV} up
        # ip route add default via ${GW}
        

2.3.3. Iptables

For more information about iptables read arch wiki. Iptables can be setup at boot with /etc/rc.d/iptables init script, change iptables.sh with your needs and run to save rules in /etc/iptables/net.v4 file.

Init script "start" option loads set of rules from file /etc/iptables/rules.v4, "open" option allows everything to outside and blocks everything from outside, "stop" will block and log everything.

Setup init script and rules ;

        # mkdir /etc/iptables
        # cp core/conf/iptables/net.v4 /etc/iptables/
        # cp core/conf/rc.d/iptables /etc/rc.d/
        # chmod +x /etc/rc.d/iptables
        

Change /etc/rc.conf and add iptables;

        SERVICES=(iptables lo net crond)
        

Adjust iptables.sh with your network configuration then run it;

        # bash core/scripts/iptables.sh
        

See current rules and packets;

        # iptables -L -n -v | less
        

2.3.4. Wpa and dhcpd

There is more information on Wiki Wifi Start Scripts and see /etc/rc.d/wlan. Manual or first time configuration;

        # ip link
        
        # iwlist wlp2s0 scan
        
        # iwconfig wlp2s0 essid NAME key s:ABCDE12345
        

2.3.4.1. Wpa Supplicant

Configure wpa supplicant edit;

        # vim /etc/wpa_supplicant.conf
        
        ctrl_interface=/var/run/wpa_supplicant
        update_config=1
        fast_reauth=1
        ap_scan=1
        
        # wpa_passphrase <ssid> <password> >> /etc/wpa_supplicant.conf
        

Now start wpa_supplicant with:

        # wpa_supplicant -B -i wlp2s0 -c /etc/wpa_supplicant.conf
        Successfully initialized wpa_supplicant
        

Use /etc/rc.d/wlan init script to auto load wpa configuration and dhcp client.

2.3.4.2. Wpa Cli

        # wpa_cli
        > status
        
        > add_network
        3
        
        > set_network 3 ssid "Crux-Network"
        OK
        
        > set_network 3 psk "uber-secret-pass"
        OK
        
        > enable_network 3
        OK
        
        > list_networks
        
        > select_network 3
        
        > save_config
        
Core OS Index

This is part of the c9-doc Manual. Copyright (C) 2017 c9 team. See the file Gnu Free Documentation License for copying conditions.