NOTE: All the commands below take effect immediately after you hit Enter, and do NOT survive reboot.
ip address show #show all IP addresses (also ip ad sh), mtu, MAC addresses ip address show ens36 #show IP addresses of a particular interface ip address show up #only show IPs of those interfaces that are up ip address show dynamic|permanent #show dynamic (DHCP) or static IPv6/IPv4 addresss ip address add 192.0.2.1/27 dev ens36 #add a new IP address to the interface
First address you added will be used as SOURCE address for outgoing traffic by default, it is often called primary address . Receiving will do for all added IPs
ip address add 192.0.2.1/29 dev ens36 label ens36:hahaha # add IP and label it ip address delete 192.0.2.1/29 dev ens36 # delete Ip address from interface ip address flush dev ens36 # delete all IPs from an interface
If you set up a static route and interface through which it is available goes down - the route is removed from active routing table as well. Also you cannot add route via inaccessible gateways.
ip route [show] / ip ro # Show the routing table, includes IPv4 and IPv6 ip -6 route # show only IPv6 , which are not shown by def ip -4 route ip route add default via 10.10.10.1 # Add default route via next hop ip route add default dev ens36 # Add default route via interface ip route add 0.0.0.0/0 dev ens36 # Add default route via the interface ip route delete default dev ens36 # Delete Default route ip route show root 192.0.2.0/24 # you can use supernet to include multiple more specific routes to show, i.e. show this net and SMALLER subnets ip route show match 192.0.2.0/29 # show routes to this and LARGER nets ip route show exact 192.168.13.0/24 # show routes to EXACT network only ip route get 184.108.40.206/24 # simulate resolving of a route in real time ip route add 220.127.116.11/24 via 10.13.77.1 # Add new route to 18.104.22.168/24 via nexthop ip route add 22.214.171.124/24 dev ens36 # Add new route to 126.96.36.199/24 via interface ip route delete 188.8.131.52/24 via 10.13.77.1 # Delete specific route ip route delete 184.108.40.206/24 # Delete specific route ip route change 220.127.116.11/24 dev ens32 # change some params of existing route ip route replace 18.104.22.168/24 dev ens36 # replace if exists add if not ip -6 route add default via 2001:db8 # Add IPv6 default route ip route add blackhole 22.214.171.124/24 # Black hole some route ip route add unreachable 10.10.10.0/24 # Block destination route, sends “Host unreachable” ip route add prohibit 10.1.1.1/32 # Block destination route, sends ICMP “Administratively prohibited” ip route add throw 10.1.1.1/32 # Block destination route, sends “net unreachable” ip route add 10.10.10.0/24 via 10.1.1.1 metric 5 # Add route with custom metrics ip route add default nexthop via 10.10.10.1 weight 1 nexthop dev ens33 weight 10 Add default route with custom weight, higher weight is preferred
Link Management - ip link
ip link show | ip link | ip link list # Show all available interfaces/links ip link show ens33 # Show information about specific interface, more verbose than above ip link set dev eth0 down | up # Set interface down or up ip link set <dev> name <new name> # Rename the interface, 1st bring interface down ip link set dev eth0 address 22:11:33:cc:33:11 # Change MAC address ip link set dev tun0 mtu 1480 # Set MTU size of interface ip link delete <dev> # Delete interface, relevant to VLAn and bridges only ip link set dev ens36 arp off|on # disable/enable ARP on interface ip link set dev ens36 multicast on|off # disable/enable multicast on interface ip link add name eth0.110 link eth0 type vlan id 110 # Add new VLAN 110 on eth0 ip link add name eth0.100 link eth0 type vlan proto 802.1ad id 100 ip link add name eth0.100.200 link eth0.100 type vlan proto 802.1q id 200 // QinQ encapsulation (available since kernel 3.10)
ip link add name peth0 link eth0 type macvlan ip link add name dummy10 type dummy # Create new interface ip link add name br0 type bridge # Create bridge interface ip link set dev eth0 master br0 # Add eth0 to the bridge ip link set dev eth0 nomaster ip link add ifb10 type ifb # Intermediate functional block interface
Links not assigned to any group belong to group 0. Group names are stored in /etc/iproute2/group file, up to 255 groups are possible.
ip link set dev eth0 group 33 ip link set dev eth0 group 0 ip link set group 33 down ip link set group 33 mtu 1300 ip link list group 33
Managing ARP table
ip neighbor show # Show MAC addresses of the neighbors ip -6 neighbor show ip neighbor show dev eth0 # show MAC addresses learned on interface eth0 ip neighbor flush dev eth0 # Delete all cached MAC addresses on interface eth0 ip neighbor add 126.96.36.199 lladdr 22:33:44:55:ff:11 dev eth0 ip neighbor delete 188.8.131.52 lladdr 22:33:44:55:ff:11 dev eth0
IPIP, SIT (IPV6 in IPV4), IP 6IP6 (IPv6 in IPv6), IPIP6 (IPv4 in IPv6), GRE, VTI kernel 3.6 or later (IPv4 in IPSec) Tunnels are created in DOWN state, dont forget to bring them up
ip tunnel add tun0 mode ipip local 192.0.2.1 remote 184.108.40.206 ip link set dev tun0 up ip address add 10.1.1.1/30 dev tun0 ip tunnel add tun9 mode sit local 192.0.2.1 remote 220.127.116.11 ip link set dev tun9 up ip addres add 2001:db8:1::1/64
Gretap tunnel - encapsulate ETH into IPv4 , used to connect L2 segments over L3. L2 interface.
# ip link add gretap0 type gretap local 192.0.2.1 remote 18.104.22.168
ip tunnel add tun7 mode gre local 192.0.2.1 remote 22.214.171.124 ip link set dev tun7 up ip address add 192.168.1.1/30 dev tun7 ip tunnel add tun11 mode gre local 192.0.2.1 key 1234 # GRE point to multipoint ip link set dev tun11 up ip add add 10.1.1.1/24 dev tun11 ip neighbor add 10.1.1.2/24 lladdr 192.0.2.1 dev tun11 ip tunnel delete tun11 ip tunnel change tun0 remote 126.96.36.199 ip tunnel show