Contents

Fast forwarding commands· 1

display ip fast-forwarding aging-time· 1

display ip fast-forwarding cache· 1

display ip fast-forwarding fragcache· 2

ip fast-forwarding aging-time· 4

ip fast-forwarding dscp· 4

ip fast-forwarding enable· 5

ip fast-forwarding load-sharing· 6

ip fast-forwarding vxlan-port 6

reset ip fast-forwarding cache· 7

 

Fast forwarding commands

display ip fast-forwarding aging-time

Use display ip fast-forwarding aging-time to display the aging time of fast forwarding entries.

Syntax

display ip fast-forwarding aging-time

Views

Any view

Predefined user roles

network-admin

network-operator

mdc-admin

mdc-operator

Examples

# Display the aging time of fast forwarding entries.

<Sysname> display ip fast-forwarding aging-time

 Aging time: 30s

Related commands

ip fast-forwarding aging-time

display ip fast-forwarding cache

Use display ip fast-forwarding cache to display fast forwarding entries.

Syntax

In standalone mode:

display ip fast-forwarding cache [ ip-address ] [ slot slot-number ]

In IRF mode:

display ip fast-forwarding cache [ ip-address ] [ chassis chassis-number slot slot-number ]

Views

Any view

Predefined user roles

network-admin

network-operator

mdc-admin

mdc-operator

Parameters

ip-address: Specifies an IP address. If you do not specify an IP address, this command displays all fast forwarding entries.

slot slot-number: Specifies a card by the slot number. If you do not specify a card, this command displays fast forwarding entries for all cards. (In standalone mode.)

chassis chassis-number slot slot-number: Specifies a card in an IRF member device. The chassis-number argument represents the member ID of the IRF member device. The slot-number represents the slot number of the card. If you do not specify a card, this command displays fast forwarding entries for all cards.(In IRF mode.)

Examples

# Display all fast forwarding entries.

<Sysname> display ip fast-forwarding cache

Total number of fast-forwarding entries: 1

SIP            SPort DIP            DPort Pro Input_If   Output_If   Flg

7.0.0.13       68    8.0.0.1        67    17  GE2/0/3    GE2/0/1     5

Table 1 Command output

Field	Description
SIP	Source IP address.
SPort	Source port number.
DIP	Destination IP address.
DPort	Destination port number.
Pro	Protocol number.
Input_If	Input interface type and number. If no interface is involved in fast forwarding, this field displays N/A. If the input interface does not exist, this field displays a hyphen (-).
Output_If	Output interface type and number. If no interface is involved in fast forwarding, this field displays N/A. If the output interface does not exist, this field displays a hyphen (-).
Flg	Internal tag, marking internal operation information, such as fragmentation.

 

Related commands

reset ip fast-forwarding cache

display ip fast-forwarding fragcache

Use display ip fast-forwarding fragcache to display fast forwarding entries for fragmented packets.

Syntax

In standalone mode:

display ip fast-forwarding fragcache [ ip-address ] [ slot slot-number ]

In IRF mode:

display ip fast-forwarding fragcache [ ip-address ] [ chassis chassis-number slot slot-number ]

Views

Any view

Predefined user roles

network-admin

network-operator

mdc-admin

mdc-operator

Parameters

ip-address: Specifies an IP address. If you do not specify an IP address, this command displays fast forwarding entries for all fragmented packets.

slot slot-number: Specifies a card by the slot number. If you do not specify a card, this command displays fast forwarding entries for fragmented packets on all cards. (In standalone mode.)

chassis chassis-number slot slot-number: Specifies a card on an IRF member device. The chassis-number argument represents the member ID of the IRF member device. The slot-number represents the slot number of the card. If you do not specify a card, this command displays fast forwarding entries for fragmented packets on all cards. (In IRF mode.)

Restrictions and guidelines

The system creates fast forwarding entries for fragments only when virtual fragment reassembly (VFR) is enabled. If VFR is disabled, this command does not display fast forwarding entries for fragments.

Examples

# Display fast forwarding entries about all fragmented packets.

<Sysname> display ip fast-forwarding fragcache

Total number of fragment fast-forwarding entries: 1

SIP             SPort DIP             DPort Pro Input_If    ID     Relay_flag

7.0.0.13        68    8.0.0.1         67    17  GE2/0/3     2

Table 2 Command output

Field	Description
SIP	Source IP address.
SPort	Source port number.
DIP	Destination IP address.
DPort	Destination port number.
Pro	Protocol number.
Input_If	Input interface type and number. If no interface is involved in fast forwarding, this field displays N/A. If the input interface does not exist, this field displays a hyphen (-).
ID	Fragment ID.
Relay_flag	Fragment pass-through flag: ·     0—Not pass through. ·     1—Pass through.

 

Related commands

reset ip fast-forwarding cache

ip fast-forwarding aging-time

Use ip fast-forwarding aging-time to configure the aging time for fast forwarding entries.

Use undo ip fast-forwarding aging-time to restore the default.

Syntax

ip fast-forwarding aging-time aging-time

undo ip fast-forwarding aging-time

Default

The aging time is 30 seconds.

Views

System view

Predefined user roles

network-admin

mdc-admin

Parameters

aging-time: Specifies the aging time in the range of 10 to 300 seconds.

Examples

# Set the aging time to 20 seconds for fast forwarding entries.

<Sysname> system-view

[Sysname] ip fast-forwarding aging-time 20

Related commands

display ip fast-forwarding aging-time

ip fast-forwarding dscp

Use ip fast-forwarding dscp to enable DSCP-based fast forwarding for GRE and VXLAN packets.

Use undo ip fast-forwarding dscp to restore the default.

Syntax

ip fast-forwarding dscp

undo ip fast-forwarding dscp

Default

DSCP-based fast forwarding for GRE and VXLAN packets is disabled.

Views

System view

Predefined user roles

network-admin

mdc-admin

Usage guidelines

This command is applicable to GRE packets (with IP as the passenger protocol) and VXLAN packets that are processed by software.

This feature uses the DSCP value in the outer header instead of the source port number among the identification criteria to identify GRE and VXLAN traffic flows.

This command is mutually exclusive with NAT and load balancing.

Examples

# Enable DSCP-based GRE and VXLAN packet fast forwarding.

<Sysname> system-view

[Sysname] ip fast-forwarding dscp

ip fast-forwarding enable

Use ip fast-forwarding enable to enable fast forwarding.

Use undo ip fast-forwarding enable to disable fast forwarding.

Syntax

ip fast-forwarding enable

undo ip fast-forwarding enable

Default

Fast forwarding is enabled.

Views

System view

Predefined user roles

network-admin

mdc-admin

Usage guidelines

The fast forwarding feature will create fast forwarding entries for the device to speed up forwarding. A large number of fast forwarding entries will cause high memory usage, which eventually leads to memory allocation failure for other services. In this case, you can disable fast forwarding temporarily to free up the device memory.

Do not disable fast forwarding if the device run services that are based on sessions. Disabling fast forwarding will make these services become ineffective:

·     NAT.

·     ASPF.

·     Attack detection and prevention.

Examples

# Disable fast forwarding.

<Sysname> system-view

[Sysname] undo ip fast-forwarding enable

Related commands

display ip fast-forwarding cache

reset ip fast-forwarding cache

ip fast-forwarding load-sharing

Use ip fast-forwarding load-sharing to enable fast forwarding load sharing.

Use undo ip fast-forwarding load-sharing to disable fast forwarding load sharing.

Syntax

ip fast-forwarding load-sharing

undo ip fast-forwarding load-sharing

Default

Fast forwarding load sharing is enabled.

Views

System view

Predefined user roles

network-admin

mdc-admin

Usage guidelines

Fast forwarding load sharing enables the device to load share packets of the same flow. This feature identifies a data flow by using the packet information.

If fast forwarding load sharing is disabled, the device identifies a data flow by the packet information and the input interface. No load sharing is implemented.

Examples

# Enable fast forwarding load sharing.

<Sysname> system-Views

[Sysname] ip fast-forwarding load-sharing

ip fast-forwarding vxlan-port

Use ip fast-forwarding vxlan-port to specify the destination UDP port number for identifying VXLAN packets.

Use undo ip fast-forwarding vxlan-port to restore the default.

Syntax

ip fast-forwarding vxlan-port port-number

undo ip fast-forwarding vxlan-port

Default

The destination UDP port number is 4789.

Views

System view

Predefined use roles

network-admin

mdc-admin

Parameters

port-number: Specifies a UDP port number in the range of 1 to 65535.

Usage guidelines

This feature is applicable to only the UDP packets that are processed by software.

In a VXLAN network, configure this command on intermediate devices to identify VXLAN packets.

Examples

# Specify the destination UDP port number to 4900 for identifying VXLAN packets.

<Sysname> system-view

[Sysname] ip fast-forwarding vxlan-port 4900

reset ip fast-forwarding cache

Use reset ip fast-forwarding cache to clear the fast forwarding table.

Syntax

In standalone mode:

reset ip fast-forwarding cache [ slot slot-number ]

In IRF mode:

reset ip fast-forwarding cache [ chassis chassis-number slot slot-number ]

Views

User view

Predefined use roles

network-admin

mdc-admin

Parameters

slot slot-number: Specifies a card by the slot number. If you do not specify a card, this command clears the fast forwarding table for all cards. (In standalone mode.)

chassis chassis-number slot slot-number: Specifies a card on an IRF member device. The chassis-number argument represents the member ID of the IRF member device. The slot-number argument represents the slot number of the card. If you do not specify a card, this command clears the fast forwarding table for all cards. (In IRF mode.)

Examples

# Clear the fast forwarding table.

<Sysname> reset ip fast-forwarding cache

Related commands

display ip fast-forwarding cache

display ip fast-forwarding fragcache