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- Table of Contents
-
- 07-Layer 3—IP Services Configuration Guide
- 00-Preface
- 01-ARP configuration
- 02-IP addressing configuration
- 03-DHCP configuration
- 04-DNS configuration
- 05-NAT configuration
- 06-IP forwarding basics configuration
- 07-Fast forwarding configuration
- 08-Multi-CPU packet distribution configuration
- 09-Adjacency table configuration
- 10-IRDP configuration
- 11-IP performance optimization configuration
- 12-UDP helper configuration
- 13-IPv6 basics configuration
- 14-DHCPv6 configuration
- 15-IPv6 fast forwarding configuration
- 16-Tunneling configuration
- 17-GRE configuration
- 18-ADVPN configuration
- 19-WAAS configuration
- 20-AFT configuration
- 21-Lighttpd service configuration
- 22-Web caching configuration
- Related Documents
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| Title | Size | Download |
|---|---|---|
| 07-Fast forwarding configuration | 46.14 KB |
Restrictions and guidelines: Fast forwarding configuration
Enabling/disabling fast forwarding
Configuring the aging time for fast forwarding entries
Configuring fast forwarding load sharing
Enabling DSCP-based fast forwarding for GRE and VXLAN packets
Display and maintenance commands for fast forwarding
Configuring fast forwarding
About fast forwarding
Fast forwarding reduces route lookup time and improves packet forwarding efficiency by using a high-speed cache and data-flow-based technology. It identifies a data flow by using the following fields: source IP address, source port number, destination IP address, destination port number, and protocol number. After a flow's first packet is forwarded through the routing table, fast forwarding creates an entry and uses the entry to forward subsequent packets of the flow.
Restrictions and guidelines: Fast forwarding configuration
Fast forwarding can process fragmented IP packets, but it does not fragment IP packets.
Fast forwarding can be implemented by software or hardware. Unless otherwise noted, fast forwarding in this chapter refers to software fast forwarding.
Enabling/disabling fast forwarding
About enabling/disabling fast forwarding
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.
Hardware and feature compatibility
|
Hardware |
Feature compatibility |
|
MSR810, MSR810-W, MSR810-W-DB, MSR810-LM, MSR810-W-LM, MSR810-10-PoE, MSR810-LM-HK, MSR810-W-LM-HK, MSR810-LMS-EA |
Yes |
|
MSR810-LMS, MSR810-LUS |
Yes |
|
MSR2600-6-X1, MSR2600-10-X1 |
Yes |
|
MSR 2630 |
Yes |
|
MSR3600-28, MSR3600-51 |
Yes |
|
MSR3600-28-SI, MSR3600-51-SI |
Yes |
|
MSR3600-28-X1, MSR3600-28-X1-DP, MSR3600-51-X1, MSR3600-51-X1-DP |
Yes |
|
MSR3610-I-DP, MSR3610-IE-DP |
No |
|
MSR3610-X1, MSR3610-X1-DP, MSR3610-X1-DC, MSR3610-X1-DP-DC |
Yes |
|
MSR 3610, MSR 3620, MSR 3620-DP, MSR 3640, MSR 3660 |
Yes |
|
MSR3610-G, MSR3620-G |
Yes |
Procedure
1. Enter system view.
system-view
2. Configure fast forwarding.
¡ Enable fast forwarding.
ip fast-forwarding enable
¡ Disable fast forwarding.
ip fast-forwarding enable
By default, fast forwarding is enabled.
Configuring the aging time for fast forwarding entries
About aging time for fast forwarding entries
The fast forwarding table uses an aging timer for each forwarding entry. If an entry is not updated before the timer expires, the device deletes the entry. If an entry has a hit within the aging time, the aging timer restarts.
Procedure
1. Enter system view.
system-view
2. Configure the aging time for fast forwarding entries.
ip fast-forwarding aging-time aging-time
By default, the aging time is 30 seconds.
Configuring fast forwarding load sharing
About fast forwarding load sharing
Fast forwarding load sharing enables the device to identify 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.
Procedure
1. Enter system view.
system-view
2. Configure fast forwarding load sharing. Choose one option as needed:
¡ Enable fast forwarding load sharing.
ip fast-forwarding load-sharing
¡ Disable fast forwarding load sharing.
undo ip fast-forwarding load-sharing
By default, fast forwarding load sharing is enabled.
Enabling DSCP-based fast forwarding for GRE and VXLAN packets
About DSCP-based fast forwarding for GRE and VXLAN packets
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.
Procedure
1. Enter system view.
system-view
2. Enable DSCP-based fast forwarding for GRE and VXLAN packets.
ip fast-forwarding dscp
By default, DSCP-based fast forwarding for GRE and VXLAN packet is disabled.
3. (Optional.) Specify the destination UDP port number for identifying VXLAN packets
ip fast-forwarding vxlan-port port-number
By default, the destination UDP port number is 4789.
Display and maintenance commands for fast forwarding
Execute display commands in any view and reset commands in user view.
|
Task |
Command |
|
Display the aging time of fast forwarding entries. |
display ip fast-forwarding aging-time |
|
Display fast forwarding entries. |
In standalone mode: display ip fast-forwarding cache [ ip-address ] In IRF mode: display ip fast-forwarding cache [ ip-address ] [ slot slot-number ] |
|
Display fast forwarding entries about fragmented packets. |
In standalone mode: display ip fast-forwarding fragcache [ ip-address ] In IRF mode: display ip fast-forwarding fragcache [ ip-address ] [ slot slot-number ] |
|
Clear the fast forwarding table. |
In standalone mode: reset ip fast-forwarding cache In IRF mode: reset ip fast-forwarding cache [ slot slot-number ] |
