route 命令

常用示例

说明

route displays and manipulates the kernel IP routing table. The kernel uses routing tables to determine where to send network packets based on their destination addresses. Without arguments, route displays the current routing table. The -n flag shows numeric addresses, avoiding DNS lookups and speeding up display. Routes can be added for networks (ranges of addresses) or specific hosts. The default route (0.0.0.0/0 for IPv4) handles traffic that doesn't match any more specific route—typically pointing to the internet gateway. The gateway specified with gw must be directly reachable via an existing route before a new route through it can be added. CIDR prefix notation (e.g., 10.0.0.0/8) is supported for the target, and is equivalent to specifying a target with a netmask. Modern Linux systems prefer ip route from the iproute2 package, but route remains available for compatibility and is familiar to administrators from older systems.

参数

-n

Show numeric addresses instead of resolving hostnames; speeds up display by avoiding DNS lookups

-v

Verbose output

-e

Display routing table in netstat(8) format; use -ee for extended output including MTU, window, and irtt columns

-C

Operate on the kernel routing cache instead of the FIB

-N

Show symbolic network names rather than CIDR notation (opposite of -n)

-4

Operate on IPv4 routes (alias for -A inet)

-6

Operate on IPv6 routes (alias for -A inet6)

-A _family_

Specify address family (e.g., inet, inet6)

-F

Operate on the kernel FIB (Forwarding Information Base) routing table (default)

-V, --version

Display version information

add

Add a new route

del

Delete a route

-net

Target is a network address

-host

Target is a single host address

gw _gateway_

Route packets via the specified gateway; the gateway must already be reachable

netmask _mask_

Specify the subnet mask for a network route

dev _interface_

Force the route to be associated with the specified network interface

metric _N_

Set the metric (priority) for the route; lower values are preferred

mss _M_

Set the TCP Maximum Segment Size (MSS) in bytes for connections using this route

window _W_

Set the TCP window size in bytes for connections using this route

irtt _I_

Set the initial round-trip time in milliseconds (1–12000) used by TCP for this route

reject

Install a blocking route that causes lookups to fail with "Network unreachable"; useful for preventing traffic to specific destinations

mod, dyn, reinstate

Diagnostic flags set by routing daemons to mark dynamic or modified routes; not normally used manually