- Table of Contents
-
- 05-Layer 3—IP Services Command Reference
- 00-Preface
- 01-ARP commands
- 02-IP addressing commands
- 03-DHCP commands
- 04-DNS commands
- 05-IP forwarding basics commands
- 06-Fast forwarding commands
- 07-Adjacency table commands
- 08-IRDP commands
- 09-IP performance optimization commands
- 10-UDP helper commands
- 11-IPv6 basics commands
- 12-DHCPv6 commands
- 13-IPv6 fast forwarding commands
- 14-Tunneling commands
- 15-HTTP redirect commands
- 16-mDNS gateway commands
- 17-mDNS relay commands
- Related Documents
-
Title | Size | Download |
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05-IP forwarding basics commands | 96.83 KB |
forwarding vxlan-packet inner-protocol
ip load-sharing local-first enable
ip load-sharing symmetric enable
Basic IP forwarding commands
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NOTE: MDC is supported only when the device operates in standalone mode. For more information about MDC, see Virtual Technologies Configuration Guide. |
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. |
forwarding split-horizon
Use forwarding split-horizon to enable split horizon forwarding.
Use undo forwarding split-horizon to disable split horizon forwarding.
Syntax
forwarding split-horizon
undo forwarding split-horizon
Default
Split horizon forwarding is disabled.
Views
System view
Layer 2 interface view
Layer 3 interface 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.
You can enable this feature globally in system view or enable this feature for a specific interface in interface view. This feature takes effect on an interface if it is enabled for the interface or enabled globally.
To disable this feature, you must disable it in both system view and interface view.
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
undo snmp-agent trap enable fib
Default
SNMP notifications for FIB events are enabled.
Views
System view
Predefined user roles
network-admin
mdc-admin
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. 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
Load sharing commands
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 ] *
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.
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.
Syntax
In standalone mode:
ip load-sharing mode per-flow [ algorithm algorithm-number [ seed seed-number ] [ shift shift-number ] | [ dest-ip | dest-port | ingress-port | ip-pro | src-ip | src-port ] * | tunnel { inner | outer } ] { 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 ] | [ algorithm-switch ] | [ dest-ip | dest-port | flow-label | ingress-port | ip-pro | src-ip | src-port ] * | tunnel { all | 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. 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.
shift shift-number: Specifies the shift value for the hash algorithm result. The value range is 0 to 31.
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.
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.
global: Configures the load sharing mode globally.
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.
Load sharing for IP tunnel packets 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.
The load-sharing mode configured for a slot takes precedence over the global load-sharing mode. The global mode takes effect only on slots not configured with a load-sharing mode.
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 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
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.
Examples
# Enable symmetric load sharing.
<Sysname> system-view
[Sysname] ip load-sharing symmetric enable