ip-route-get

Get route to destination address

TLDR

Print route to a destination

$ ip [[r|route]] [[g|get]] [1.1.1.1]

Print route to a destination from a specific source address

$ ip [[r|route]] [[g|get]] [destination] from [source]

Print route to a destination for packets arriving on a specific interface

$ ip [[r|route]] [[g|get]] [destination] iif [eth0]

Print route to a destination, forcing output through a specific interface

$ ip [[r|route]] [[g|get]] [destination] oif [eth1]

Print route to a destination with a specified Type of Service (ToS)

$ ip [[r|route]] [[g|get]] [destination] tos [0x10]

Print route to a destination using a specific VRF (Virtual Routing and Forwarding) instance

$ ip [[r|route]] [[g|get]] [destination] vrf [myvrf]

SYNOPSIS

ip route get ADDRESS [ from ADDRESS ] [ iif STRING ] [ oif STRING ] [ tos TOS ] [ vrf NAME ] [ connected ] [ fibmatch ]

ADDRESS
    The destination IP address to look up.

from ADDRESS
    The source IP address to use for the lookup.

iif STRING
    The incoming interface name to use for the lookup. If specified, lookup only valid for packets entering through this interface.

oif STRING
    The outgoing interface name to use for the lookup. If specified, the lookup considers routes only leaving the selected interface.

tos TOS
    The Type of Service (TOS) value to use for the lookup.

vrf NAME
    The VRF (Virtual Routing and Forwarding) instance to use for the lookup.

connected
    Forces the command to look for a directly connected route, ignoring non-connected routes. Will only work with a valid iif.

fibmatch
    Requests fib_rules lookup for destination, by default all rules are bypassed.

DESCRIPTION

The `ip route get` command is a powerful tool for querying the kernel's routing table. It allows you to determine the path that packets will take to reach a specific destination IP address. It provides details about the route, including the source address used, the gateway, the interface, and any relevant routing rules or policy routing settings. This is invaluable for troubleshooting network connectivity issues, understanding routing behavior, and verifying network configurations. The command can be used to simulate packet delivery by providing a destination IP address and other optional parameters (like source IP address or interface) and shows how the system would attempt to route the packet. It's an integral part of the `iproute2` suite, a collection of utilities for managing network interfaces, routing, and tunneling on Linux systems.

EXAMPLE USAGE

To find the route to 8.8.8.8:
ip route get 8.8.8.8

To find the route to 192.168.1.1 using source address 10.0.0.1:
ip route get 192.168.1.1 from 10.0.0.1