Contents

IP forwarding basics· 1

Basic IP forwarding commands· 1

display fib· 1

fib consistency-check enable· 3

forwarding split-horizon· 3

forwarding vxlan-packet inner-protocol 4

ip forwarding· 5

ip forwarding-table save· 5

snmp-agent trap enable fib· 6

snmp-agent trap enable ip-forwarding· 7

Load sharing commands· 9

bandwidth-based-sharing· 9

display ip load-sharing mode· 9

display ip load-sharing path· 11

ip load-sharing local-first enable· 13

ip load-sharing mode· 13

ip load-sharing mode per-packet 16

ip load-sharing symmetric enable· 17

 

IP forwarding basics

Basic IP forwarding commands

display fib

Use display fib to display FIB entries.

Syntax

display fib [vpn-instance vpn-instance-name ]  [ ip-address [ mask | mask-length ] ]

Views

Any view

Predefined user roles

network-admin

network-operator

mdc-admin

mdc-operator

Parameters

vpn-instance vpn-instance-name: Specifies an MPLS L3VPN instance by its name, a case-sensitive string of 1 to 31 characters. To display the FIB entries for the public network, do not specify any VPN instance.

ip-address: Displays the FIB entry that matches the specified destination IP address.

mask: Specifies the mask for the IP address.

mask-length: Specifies the mask length for the IP address. The value range is 0 to 32.

Usage guidelines

If you specify an IP address without a mask or mask length, this command displays the longest matching FIB entry.

If you specify an IP address and a mask or mask length, this command displays the exactly matching FIB entry.

Examples

# Display all FIB entries of the public network.

<Sysname> display fib

 

Destination count: 5 FIB entry count: 5

 

Flag:

  U:Usable   G:Gateway   H:Host   B:Blackhole   D:Dynamic   S:Static

  R:Relay     F:FRR

 

Destination/Mask   Nexthop         Flag     OutInterface/Token       Label

0.0.0.0/32         127.0.0.1       UH       InLoop0                  Null

1.1.1.0/24         192.168.126.1   USGF     M-GE0/0/0                Null

127.0.0.0/8        127.0.0.1       U        InLoop0                  Null

127.0.0.0/32       127.0.0.1       UH       InLoop0                  Null

127.0.0.1/32       127.0.0.1       UH       InLoop0                  Null

# Display the FIB entries for VPN vpn1.

<Sysname> display fib vpn-instance vpn1

Destination count: 6 FIB entry count: 6

Flag:

  U:Usable   G:Gateway   H:Host   B:Blackhole   D:Dynamic   S:Static

  R:Relay     F:FRR

Destination/Mask   Nexthop         Flag     OutInterface/Token      Label

0.0.0.0/32         127.0.0.1       UH       InLoop0                  Null

20.20.20.0/24      20.20.20.25     U        M-GE0/0/0                Null

20.20.20.0/32      20.20.20.25     UBH      M-GE0/0/0                Null

20.20.20.25/32     127.0.0.1       UH       InLoop0                  Null

20.20.20.25/32     20.20.20.25     H        M-GE0/0/0                Null

20.20.20.255/32    20.20.20.25     UBH      M-GE0/0/0                Null

# Display the FIB entries matching the destination IP address 10.2.1.1.

<Sysname> display fib 10.2.1.1

 

Destination count: 1 FIB entry count: 1

 

Flag:

  U:Usable   G:Gateway   H:Host   B:Blackhole   D:Dynamic   S:Static

  R:Relay     F:FRR

 

Destination/Mask   Nexthop         Flag     OutInterface/Token       Label

10.2.1.1/32        127.0.0.1       UH       InLoop0                  Null

Table 1 Command output

Field	Description
Destination count	Total number of destination addresses.
FIB entry count	Total number of FIB entries.
Destination/Mask	Destination address and the mask length.
Nexthop	Next hop address.
Flag	Flags of routes: ·     U—Usable route. ·     G—Gateway route. ·     H—Host route. ·     B—Blackhole route. ·     D—Dynamic route. ·     S—Static route. ·     R—Relay route. ·     F—Fast reroute.
OutInterface/Token	Output interface/LSP index number.
Label	Inner label.

 

fib consistency-check enable

Use fib consistency-check enable to enable IPv4 FIB entry consistency check.

Use undo fib consistency-check enable to disable IPv4 FIB entry consistency check.

Syntax

fib consistency-check enable

undo fib consistency-check enable

Default

IPv4 FIB entry consistency check is disabled.

Views

System view

Predefined user roles

network-admin

mdc-admin

Usage guidelines

Packet drops or incorrect forwarding might occur when the IPv4 FIB entries in hardware are inconsistent with FIB entries configured in software. To prevent these issues, enable IPv4 FIB entry consistency check.

This feature compares all IPv4 FIB entries in software with the IPv4 FIB entries in hardware regularly. If the device detects an inconsistency, the device performs the following tasks:

·     Generates a log.

·     Updates the IPv4 FIB entry in hardware with the IPv4 FIB entry in software.

Examples

# Enable IPv4 FIB entry consistency check.

<Sysname> system-view

[Sysname] fib consistency-check enable

forwarding split-horizon

Use forwarding split-horizon to enable split horizon forwarding.

Use undo forwarding split-horizon to disable split horizon forwarding.

 

NOTE: Only SC modules prefixed with LSCM2, SD interface modules, and SF interface modules support this feature.

 

Syntax

forwarding split-horizon

undo forwarding split-horizon

Default

Split horizon forwarding is disabled.

Views

System view

Predefined user roles

network-admin

mdc-admin

Usage guidelines

This feature prevents IPv4, IPv6, and MPLS packets from being forwarded out of the physical interface on which they were received, avoiding network loops.

Examples

# Enable split horizon forwarding globally.

<Sysname> system-view

[Sysname] forwarding split-horizon

forwarding vxlan-packet inner-protocol

Use forwarding vxlan-packet inner-protocol to enable hardware forwarding for specific packets received from VXLAN tunnels.

Use undo forwarding vxlan-packet inner-protocol to restore the default.

Syntax

forwarding vxlan-packet inner-protocol { ipv4 | ipv6 } *

undo forwarding vxlan-packet inner-protocol [ ipv4 | ipv6 ]

Default

Packets received from VXLAN tunnels are delivered to the CPU for processing.

Views

System view

Predefined user roles

network-admin

mdc-admin

Parameters

ipv4: Specifies IPv4 packets.

ipv6: Specifies IPv6 packets.

Usage guidelines

By default, the device forwards packets received from VXLAN tunnels to the CPU for processing when acting as a VTEP in a distributed EVPN gateway network. If a large number of packets are received, packet loss might occur because of software rate limit, which might cause service exceptions on downlink devices.

To resolve this issue, you can enable the device to forward specific packets received from VXLAN tunnels in hardware without delivering them to the CPU.

Examples

# Enable hardware forwarding for IPv4 packets received from VXLAN tunnels.

<Sysname> system-view

[Sysname] forwarding vxlan-packet inner-protocol ipv4

ip forwarding

Use ip forwarding to enable IPv4 packet forwarding on an interface that has no IPv4 address configured.

Use undo ip forwarding to disable IPv4 packet forwarding on an interface that has no IPv4 address configured.

Syntax

ip forwarding

undo ip forwarding

Default

If an interface has no IPv4 address configured, the IPv4 packet forwarding is disabled on the interface.

Views

Interface view

Predefined user roles

network-admin

mdc-admin

Usage guidelines

On a device that supports both IPv4 and IPv6, the next hop of an IPv4 packet might be an IPv4 address or an IPv6 address. If the output interface has no IPv4 address configured, the interface cannot forward the IPv4 packet. To solve this problem, execute this command on the interface. This feature allows the interface to forward IPv4 packets even though the interface has no IPv4 address configured.

Examples

# Enable IPv4 packet forwarding on VLAN-interface 1 that has no IPv4 address configured.‌

<Sysname> system-view

[Sysname] interface vlan-interface 1

[Sysname-Vlan-interface1] ip forwarding

ip forwarding-table save

Use ip forwarding-table save to save the IP forwarding entries to a file.

Syntax

ip forwarding-table save filename filename

Views

Any view

Predefined user roles

network-admin

mdc-admin

Parameters

filename filename: Specifies the name of a file, a string of 1 to 255 characters. For information about the filename argument, see file system management in Fundamentals Configuration Guide.

Usage guidelines

The command automatically creates the file if you specify a nonexistent file. If the file already exists, this command overwrites the file content.

To automatically save the IP forwarding entries periodically, configure a schedule for the device to automatically run the ip forwarding-table save command. For information about scheduling a task, see Fundamentals Configuration Guide.

Examples

# Save the IP forwarding entries to the fib.txt file.

<Sysname> ip forwarding-table save filename fib.txt

snmp-agent trap enable fib

Use snmp-agent trap enable fib to enable SNMP notifications for FIB events.

Use undo snmp-agent trap enable fib to disable SNMP notifications for FIB events.

Syntax

snmp-agent trap enable fib [ deliver-failed | ecmp-limit | entry-consistency | entry-limit ] *

undo snmp-agent trap enable fib [ deliver-failed | ecmp-limit | entry-consistency | entry-limit ] *

Default

SNMP notifications for FIB events are enabled.

Views

System view

Predefined user roles

network-admin

mdc-admin

Parameters

deliver-failed: Specifies notifications to be sent when FIB entry deployment to the hardware fails.

ecmp-limit: Specifies notifications to be sent when the number of ECMP routes exceeds the upper limit.

entry-consistency: Specifies notifications to be sent when the FIB software and hardware entries are inconsistent.

entry-limit: Specifies notifications to be sent when the number of FIB entries exceeds the upper limit.

Usage guidelines

This feature enables the FIB module to generate SNMP notifications for critical FIB events. The SNMP notifications are sent to the SNMP module.

You can enable specific SNMP notifications for FIB events as needed. If you do not specify any SNMP notification types, the command enables all types of SNMP notifications.

·     With ecmp-limit specified, when the number of ECMP routes learned by a module exceeds the upper limit, the device sends an SNMP notification that carries the module number to the SNMP module.

·     With entry-consistency specified, if the FIB software and hardware entries on a module are inconsistent, the device sends an SNMP notification that carries the module number to the SNMP module.

·     With entry-limit specified, when the number of FIB entries exceeds the upper limit, the device sends an SNMP notification that carries the FIB entry module name to the SNMP module.

·     With deliver-failed specified, when FIB entry deployment to the hardware fails, the device sends an SNMP notification that carries the entry VRF, IP address type, IP address, mask, and failure reason to the SNMP module.

For the SNMP notifications to be sent correctly, you must also configure SNMP. For more information about SNMP configuration, see Network Management and Monitoring Configuration Guide.

Examples

# Disable SNMP notifications for FIB events.

<Sysname> system-view

[Sysname] undo snmp-agent trap enable fib

snmp-agent trap enable ip-forwarding

Use snmp-agent trap enable ip-forwarding to enable SNMP notifications for IP forwarding events.

Use undo snmp-agent trap enable ip-forwarding to disable SNMP notifications for IP forwarding events.

Syntax

snmp-agent trap enable ip-forwarding [ ttl-expired | mbuf-alloc ]

undo snmp-agent trap enable ip-forwarding

Default

SNMP notifications for IP forwarding events are enabled.

Views

System view

Predefined user roles

network-admin

mdc-admin

Parameters

ttl-expired: Specifies notifications about TTL timeout.

mbuf-alloc: Specifies notifications about MBUF allocation failures.

Usage guidelines

This feature enables the IP forwarding module to generate SNMP notifications for critical IP forwarding events. The SNMP notifications are sent to the SNMP module. For the SNMP notifications to be sent correctly, you must also configure SNMP. For more information about SNMP configuration, see Network Management and Monitoring Configuration Guide.

You can enable SNMP notifications for the following IP forwarding events as needed:

·     After you enable SNMP notifications about TTL timeout, the device checks the number of dropped packets at the specified time interval. An SNMP notification is generated and sent to the SNMP module when the number of dropped packets reaches or exceeds the specified threshold.

·     After you enable SNMP notifications about MBUF allocation failures, an SNMP notification is generated and sent to the SNMP module when MBUF allocation fails.

If you do not specify any parameters, the command enables all types of SNMP notifications for IP forwarding events.

After you disable the SNMP notifications for IP forwarding events, the device sends only logs to the device's information center module. In this case, you can configure the log output destinations and output rules to view the log information of the basic IPv6 modules. For more information about configuring the information center, see information center configuration in Network Management and Monitoring Configuration Guide.

Examples

# Disable SNMP notifications for IP forwarding events.

<Sysname> system-view

[Sysname] undo snmp-agent trap enable ip-forwarding

Load sharing commands

bandwidth-based-sharing

Use bandwidth-based-sharing to enable IPv4 load sharing based on bandwidth.

Use undo bandwidth-based-sharing to disable IPv4 load sharing based on bandwidth.

 

NOTE: Only the SF interface modules support this feature.

 

Syntax

bandwidth-based-sharing

undo bandwidth-based-sharing

Default

The IPv4 load sharing based on bandwidth is disabled.

Views

System view

Predefined user roles

network-admin

mdc-admin

Usage guidelines

This feature load shares flow traffic among multiple output interfaces based on their load percentages. The device calculates the load percentage for each output interface in terms of their expected bandwidths.

Devices that run load sharing protocols, such as Locator/ID Separation Protocol (LISP), implement load sharing based on the ratios defined by these protocols.

This feature is supported only in normal ECMP mode. For more information about ECMP modes, see IP routing basics commands in Layer 3—IP Routing Command Reference.

If per-packet load sharing is enabled on multiple interfaces of the device, those interfaces cannot be used for IPv4 bandwidth-based load sharing.

Examples

# Enable IPv4 load sharing based on bandwidth.

<Sysname> system-view

[Sysname] bandwidth-based-sharing

display ip load-sharing mode

Use display ip load-sharing mode to display the load sharing mode in use.

Syntax

In standalone mode:‌

display ip load-sharing mode slot slot-number

In IRF mode:

display ip load-sharing mode chassis chassis-number slot slot-number

Views

Any view

Predefined user roles

network-admin

network-operator

mdc-admin

mdc-operator

Parameters

slot slot-number: Specifies a card by its slot number. If you do not specify a card, this command displays the load sharing mode 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 displays the load sharing mode for all cards. (In IRF mode.) ‌

Examples

# Display the load sharing mode in use.

<Sysname> display ip load-sharing mode slot 1

Load-sharing mode: per-flow

Load-sharing options: dest-ip | src-ip | ip-pro | dest-port | src-port | ingress-port

Load-sharing algorithm: 1

IP tunnel load-sharing mode: outer

Table 2 Command output

Field	Description
Load-sharing mode	The load sharing mode in use: ·     per-packet—Per-packet load sharing. ·     per-flow—Per-flow load sharing.
Load-sharing options	Options configured for load sharing: ·     dest-ip—Identifies flows by packet's destination IP address. ·     src-ip—Identifies flows by packet's source IP address. ·     ip-pro—Identifies flows by packet's IP protocol. ·     dest-port—Identifies flows by packet's destination port number. ·     src-port—Identifies flows by packet's source port number. ·     ingress-port—Identifies flows by packet's ingress port. ·     flow-label—Identifies flows by IPv6 packet's flow label.
Load-sharing algorithm	Algorithm used by load sharing.
IP tunnel load-sharing mode	Load sharing for IP tunnel packets: ·     inner—Identifies flows by inner IP header information. ·     outer—Identifies flows by outer IP header information.

 

Related commands

ip load-sharing mode

display ip load-sharing path

Use display ip load-sharing path to display the load sharing path selected for a flow.

Syntax

display ip load-sharing path ingress-port interface-type interface-number packet-format { ipv4oe dest-ip ip-address [ src-ip ip-address ] | ipv6oe dest-ipv6 ipv6-address [ src-ipv6 ipv6-address | flow-label flow-label ] } [ dest-port port-id | ip-pro protocol-id | src-port port-id | vpn-instance vpn-instance-name ] *

Only SC modules prefixed with LSCM2, SD interface modules, SE interface modules, and SF interface modules support this feature.

Views

Any view

Predefined user roles

network-admin

network-operator

mdc-admin

mdc-operator

Parameters

ingress-port interface-type interface-number: Specifies an ingress port by its type and number.

packet-format { ipv4oe dest-ip ip-address [src-ip ip-address ] | ipv6oe dest-ipv6 ipv6-address [ src-ipv6 ipv6-address ] }: Specifies the packet encapsulation format.

ipv4oe: Specifies the format of IPv4 over Ethernet.

dest-ip ip-address: Specifies the destination IPv4 address in dotted decimal notation. If you do not specify this argument, the calculation uses 0.0.0.0 for path selection.

src-ip ip-address: Specifies the source IPv4 address in dotted decimal notation. If you do not specify this argument, the calculation uses 0.0.0.0 for path selection.

ipv6oe: Specifies the format of IPv6 over Ethernet.

dest-ipv6 ipv6-address: Specifies the destination IPv6 address. If you do not specify this option, the calculation uses 0:0:0:0:0:0:0:0 for path selection.

src-ipv6 ipv6-address: Specifies the source IPv6 address. If you do not specify this option, the calculation uses 0:0:0:0:0:0:0:0 for path selection.

flow-label flow-label: Specifies the IPv6 flow label in the range of 0 to 1048575. If you do not specify an IPv6 flow label, the device uses 0 for ECMP route selection.

dest-port port-id: Specifies a destination port number in the range of 1 to 65535. If you do not specify this option, the calculation uses 0 for path selection.

ip-pro protocol-id: Specifies an IP protocol by its number in the range of 1 to 65535. If you do not specify this option, the calculation uses 0 for path selection.

source-port port-id: Specifies a source port number in the range of 1 to 65535. If you do not specify this option, the calculation uses 0 for path selection.

vpn-instance vpn-instance-name: Specifies an MPLS L3VPN instance by its name, a case-sensitive string of 1 to 31 characters. To display the path on the public network, do not specify this option.

Usage guidelines

The option settings in this command must match both the options displayed in the display ip load-sharing mode command and the field values in load shared packets. If the option settings do not meet the requirement, the path displayed by this command might be different from the real path for load sharing.

The command cannot display egress interface information or tunnel encapsulation packet information for non-known unicast packets.

If the load sharing mode specified by the ip load-sharing mode command is per-packet, the path displayed by this command will be different from the real path for load sharing.

Examples

# Display the load sharing path selected for the flow with the following attributes: ingress port Ten-GigabitEthernet 3/0/3, destination IP address 10.110.0.2, source IP address 10.100.0.2, IP protocol number 153, destination port number 2000, source port number 2000.

<Sysname> display ip load-sharing path ingress-port ten-gigabitethernet 3/0/3 packet-format ipv4oe dest-ip 10.110.0.2 src-ip 10.100.0.2 ip-pro 153 dest-port 2000 src-port 2000

 

Load-sharing algorithm: 0

Load-sharing options: dest-ip | src-ip | ip-pro | dest-port | src-port | ingress-port

Load-sharing parameters:

  Missing configured are set to 0.

  ingress-port: Ten-GigabitEthernet3/0/3

  packet-format: IPv4oE

  dest-ip: 10.110.0.2

  src-ip: 10.100.0.2

  ip-pro: 153

  dest-port: 2000

  src-port: 2000

Path selected: 20.0.0.2(interface Ten-GigabitEthernet3/0/3)

Table 3 Command output

Field	Description
Load-sharing algorithm	Load sharing algorithm ID.
Load-sharing options	Load sharing options specified by the ip load-sharing mode command.
Load-sharing parameters	Load sharing parameters that you specify for the display ip load-sharing path command.
Missing configured are set to 0.	Values of the unconfigured parameters are set to 0.
ingress-port	Ingress port of the packet.
packet-format	Packet encapsulation format.
dest-ip	Destination IP address of the packet.
src-ip	Source IP address of the packet.
ip-pro	IP protocol number.
dest-port	Destination port number.
src-port:	Source port number.
flow-label	Flow label.
Path selected	Selected path information, including the IPv4 or IPv6 address of the next hop and the egress port.

 

Related commands

ip load-sharing mode

ip load-sharing local-first enable

Use ip load-sharing local-first enable to enable local-first load sharing.

Use undo ip load-sharing local-first enable to disable local-first load sharing.

Syntax

ip load-sharing local-first enable

undo ip load-sharing local-first enable

Default

Local-first load sharing is enabled.

Views

System view

Predefined user roles

network-admin

mdc-admin

Usage guidelines

Local-first load sharing takes effect only on an IRF fabric.

Examples

# Enable local-first load sharing.

<Sysname> system-view

[Sysname] ip load-sharing local-first enable

ip load-sharing mode

Use ip load-sharing mode to configure the load sharing mode.

Use undo ip load-sharing mode to restore the default.

‌

NOTE: ·     Per-packet load sharing takes effect only on SC interface modules prefixed with LSCM2, SD interface modules, and SF interface modules. ·     In VXLAN networks, per-packet load sharing cannot take effect on SF interface modules.

‌

Syntax

In standalone mode:‌

ip load-sharing mode { per-flow [ algorithm algorithm-number [ seed seed-number ] [ shift shift-number ] | [ dest-ip | dest-port | flow-label | ingress-port | ip-pro | src-ip | src-port ] * | tunnel { inner | outer } ] | per-packet } { global | slot slot-number }

undo ip load-sharing mode [ per-flow { algorithm | tunnel } ] { global | slot slot-number }

In IRF mode:

ip load-sharing mode { per-flow [ algorithm algorithm-number [ seed seed-number ] [ shift shift-number ] | [ dest-ip | dest-port  | flow-label | ingress-port | ip-pro | src-ip | src-port ] * | tunnel { inner | outer } ] | per-packet } { chassis chassis-number slot slot-number | global }

undo ip load-sharing mode [ per-flow { algorithm | tunnel } ] { chassis chassis-number slot slot-number | global }

Default

The device performs per-flow load sharing based on the following criteria: source IP address, destination IP address, source port number, destination port number, and IP protocol number.

Views

System view

Predefined user roles

network-admin

mdc-admin

Parameters

algorithm algorithm-number: Specifies an algorithm for per-flow load sharing. For the SC modules prefixed with LSCM2, SD interface modules, and SF series interface mdouels, the value range for the algorithm-number argument is 0 to 13. For the SE interface modules and the LSCM1GT48SC0 module, the value range for the algorithm-number argument is 0 to 1. If you specify an algorithm, and then execute the undo ip load-sharing mode command, the algorithm value is set to 0.  

seed seed-number: Specifies the seed value for the algorithm. The value range is 0 to ffffffff.

Only SC modules prefixed with LSCM2, SD interface modules, and SF interface modules support this option.

shift shift-number: Specifies the shift value for the hash algorithm result. The value range is 0 to 31.

Only SC modules prefixed with LSCM2, SD interface modules, and SF interface modules support this option.

per-flow: Implements per-flow load sharing. If you specify none of the dest-ip, dest-port, ingress-port, ip-pro, src-ip, and src-port keywords, the device performs per-flow load sharing based on the destination IP addresses and source IP addresses of packets.

dest-ip: Identifies flows by destination IP address.

dest-port: Identifies flows by destination port.

flow-label: Identifies flows by flow label. This keyword takes effect only on IPv6 packets.

Only SC modules prefixed with LSCM2, SD interface modules, and SF interface modules support this keyword.

ingress-port: Identifies flows by ingress port.

ip-pro: Identifies flows by protocol number.

src-ip: Identifies flows by source IP address.

src-port: Identifies flows by source port.

tunnel { inner | outer }: Performs per-flow load sharing for IP tunnel packets. The inner keyword identifies flows by inner IP header information. The outer keyword identifies flows by outer IP header information. If you do not specify this option, the device identifies IP tunnel packet flows by outer IP header information to implement load sharing.

 

NOTE: This option is supported only by SD interface modules, SE interface modules, SF interface modules, and SC modules prefixed with LSCM2.

 

global: Configures the load sharing mode globally.

per-packet: Implements per-packet load sharing.

slot slot-number: Specifies a card by its slot number. If you do not specify a card, this command configures the load sharing mode 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 configures the load sharing mode for all cards. (In IRF mode.) ‌

Usage guidelines

If traffic is not shared equally, you can use the seed seed-number option and the shift shift-number option to adjust the algorithm result.

Load sharing hash seed does not take effect on non-known unicast packets.

IP Tunnel does not take effect on non-known unicast packets.

For MPLS packets, the device only supports per-flow load sharing based on their source IP addresses or destination IP addresses.

If IPv6 packets are encapsulated by MPLS, they do not support flow label-based per-flow load sharing.

The priority of slot-specific load balancing is higher than the global load balancing method. The global configuration takes effect only on slots that are not specified with a load balancing method.

Per-packet load sharing is supported only when the ECMP mode is normal. For more information about ECMP modes, see IP routing basics commands in Layer 3—IP Routing Command Reference.

Enabling per-packet load sharing will cause packets to be out-of-order. As a best practice, use this feature only if packet disorder does not interrupt services.

By default, the device performs per-flow load sharing based on the following criteria: source IP address, destination IP address, source port number, destination port number, and IP protocol number. The first fragment and the other fragments of the same packet might be forwarded through different output ports. When the device uses SE interface modules or LSCM1GT48SC0 cards, the result of packet fragment reassembly might be strongly related to the packet forwarding path. In this situation, packet fragment reassembly might fail when fragments of the same packet are forwarded along different forwarding paths. To resolve this issue, re-execute the ip load-sharing mode command without specifying the dest-port and src-port keywords.

Examples

# (In standalone mode.) ‌Configure per-flow load sharing for slot 1.

<Sysname> system-view

[Sysname] ip load-sharing mode per-flow slot 1

# (In standalone mode.) ‌Configure per-flow load sharing based on the destination IP addresses and source IP addresses of packets for slot 1.

<Sysname> system-view

[Sysname] ip load-sharing mode per-flow dest-ip src-ip slot 1

# (In standalone mode.) ‌Configure per-flow load sharing based on the inner IP header information of IP tunnel packets for slot 1.

<Sysname> system-view

[Sysname] ip load-sharing mode per-flow tunnel inner slot 1

# (In standalone mode.) ‌Configure per-flow load sharing based on algorithm 1 for slot 1.

<Sysname> system-view

[Sysname] ip load-sharing mode per-flow algorithm 1 slot 1

Related commands

display ip load-sharing mode

ip load-sharing mode per-packet

Use ip load-sharing mode per-packet to enable per-packet load sharing on an interface and set the load sharing algorithm.

Use undo ip load-sharing mode per-packet to restore the default.

 

NOTE: Only SC modules prefixed with LSCM2, SD interface modules, and SF interface modules support this feature.

 

Syntax

ip load-sharing mode per-packet  robin

undo ip load-sharing mode per-packet

Default

No load sharing mode is specified on an interface. The interface uses the load sharing settings configured by using the ip load-sharing mode command in system view.

Views

Layer 3 interface view

Predefined user roles

network-admin

mdc-admin

Parameters

robin: Specifies the robin algorithm, an algorithm that considers only the packet quantity.

Usage guidelines

In scenarios where service traffic and packets are forwarded through fixed interfaces, per-packet load sharing has higher performance than per-flow load sharing. When per-flow load sharing applies globally, you can use this command to enable per-packet load sharing on specific interfaces and set the load sharing algorithm for device performance test purposes. In per-packet load sharing, the robin algorithm does not consider the packet size

With this command configured, the interfaces do not inherit the load sharing settings of the ip load-sharing mode command in system view.

The feature is not supported on VSI interfaces.

After you use this command, the output of the display ip load-sharing mode command might be inconsistent with the real.

Examples

# On GigabitEthernet 1/0/1, enable per-packet load sharing.

<Sysname> system-view

[Sysname] interface gigabitethnet 1/0/1

[Sysname-GigabitEthnet1/0/1] ip load-sharing mode per-packet robin

ip load-sharing symmetric enable

Use ip load-sharing symmetric enable to enable symmetric load sharing.

Use undo ip load-sharing symmetric enable to disable symmetric load sharing.

Syntax

ip load-sharing symmetric enable

undo ip load-sharing symmetric enable

Only SC modules prefixed with LSCM2, SD interface modules, and SF interface modules support this feature.

Default

Symmetric load sharing is disabled.

Views

System view

Predefined user roles

network-admin

mdc-admin

Usage guidelines

Symmetric load sharing ensures that bidirectional traffic specific to a particular source and destination address pair flow along the same path.

Symmetric load sharing takes effect only on known unicast packets.

As a best practice to ensure effective symmetric load sharing, configure load sharing based only on the source and destination IP addresses.

Examples

# Enable symmetric load sharing.

<Sysname> system-view

[Sysname] ip load-sharing symmetric enable