Basic MPLS commands 1

display mpls forwarding ilm·· 1

display mpls forwarding nhlfe· 2

display mpls interface· 4

display mpls label 5

display mpls lsp· 6

display mpls lsp statistics 11

display mpls nib· 11

display mpls nid· 12

display mpls summary· 13

mpls enable· 14

mpls label advertise· 15

mpls lsr-id· 16

mpls mtu· 17

mpls ttl expiration enable· 17

mpls ttl propagate· 18

snmp-agent trap enable mpls 19

 

display mpls forwarding ilm

Use display mpls forwarding ilm to display Incoming Label Map (ILM) entries.

Syntax

In standalone mode:

display mpls forwarding ilm [ label ] [ slot slot-number ]

In IRF mode:

display mpls forwarding ilm [ label ] [ chassis chassis-number slot slot-number ]

Views

Any view

Predefined user roles

network-admin

network-operator

mdc-admin

mdc-operator

Parameters

label: Displays the ILM entry with the specified incoming label. The value range for this argument is 16 to 1048575. If you do not specify an incoming label, this command displays information about all ILM entries on the specified card.

slot slot-number: Specifies a card by its slot number. (In standalone mode.)

chassis chassis-number slot slot-number: Specifies a card on an IRF member device. The chassis-number argument specifies the member ID of the IRF member device. The slot-number argument specifies the slot number of the card. (In IRF mode.)

Usage guidelines

An ILM entry records the label operation type, outgoing label, and other forwarding information.

After an LSR receives a labeled packet, it performs the following operations:

1.     Identifies the ILM entry that matches the top label of the packet.

2.     Performs the specified label operation.

3.     Forwards the packet.

Examples

# Display the ILM entry with incoming label 30.

<Sysname> display mpls forwarding ilm 30

Flags: T - Forwarded through a tunnel

       N - Forwarded through the outgoing interface to the nexthop IP address

       B - Backup forwarding information

       A - Active forwarding information

 

InLabel Oper    VRF   Flag SwapLabel Forwarding Info

--------------------------------------------------------------------------------

30      SWAP    0     T    1300      1024

# Display all ILM entries.

<Sysname> display mpls forwarding ilm

Total ILM entries: 3

 

Flags: T - Forwarded through a tunnel

       N - Forwarded through the outgoing interface to the nexthop IP address

       B - Backup forwarding information

       A - Active forwarding information

 

InLabel Oper    VRF   Flag SwapLabel Forwarding Info

--------------------------------------------------------------------------------

30      SWAP    0     T    1300      1024

1279    POP     0     -    -         -

1407    SWAP    0     NA   1271      GE3/0/3                  50.2.0.2

                      NB   1270      Tun0                     0.0.0.0

Table 1 Command output

Field	Description
Total ILM entries	Total number of ILM entries.
InLabel	Incoming label.
Oper	Operation type: ·     POP—Pops the label. ·     POPGO—Pops the label and forwards the packet to another tunnel. ·     SWAP—Swaps the label.
VRF	Index of a VPN instance.
Flag	Forwarding flag: ·     T—Forwarded through a tunnel. ·     N—Forwarded through the outgoing interface to the next hop IP address. ·     B—Backup forwarding information. ·     A—Active forwarding information.
SwapLabel	Outgoing label value.
Forwarding Info	Forwarding information: ·     When the forwarding flag is N, the forwarding information records the outgoing interface and the next hop. ·     When the forwarding flag is T, the forwarding information records the NID.

 

display mpls forwarding nhlfe

Use display mpls forwarding nhlfe to display Next Hop Label Forwarding Entry (NHLFE) entries.

Syntax

In standalone mode:

display mpls forwarding nhlfe [ nid ] [ slot slot-number ]

In IRF mode:

display mpls forwarding nhlfe [ nid ] [ chassis chassis-number slot slot-number ]

Views

Any view

Predefined user roles

network-admin

network-operator

mdc-admin

mdc-operator

Parameters

nid: Displays the NHLFE entry with the specified NID. The NID value range is 0 to 4294967294. If you do not specify an NID, this command displays information about all NHLFE entries on the specified card.

slot slot-number: Specifies a card by its slot number. (In standalone mode.)

chassis chassis-number slot slot-number: Specifies a card on an IRF member device. The chassis-number argument specifies the member ID of the IRF member device. The slot-number argument specifies the slot number of the card. (In IRF mode.)

Usage guidelines

An NHLFE entry records label forwarding information, such as the outgoing label and outgoing interface. NHLFE entries are mainly used to add multiple labels to packets.

To add multiple labels to a packet, an LSR performs the following operations:

1.     Obtains the bottom label and NID in the matching FIB or ILM entry.

2.     Obtains the outer label in the NHLFE entry identified by the NID.

Examples

# Display the NHLFE entry with NID 2048.

<Sysname> display mpls forwarding nhlfe 2048

Flags: T - Forwarded through a tunnel

       N - Forwarded through the outgoing interface to the nexthop IP address

       B - Backup forwarding information

       A - Active forwarding information

 

NID        Tnl-Type Flag OutLabel Forwarding Info

--------------------------------------------------------------------------------

2048       LSP      NA   2025     GE3/0/2                  10.11.112.26

# Display all NHLFE entries.

<Sysname> display mpls forwarding nhlfe

Total NHLFE entries: 5

 

Flags: T - Forwarded through a tunnel

       N - Forwarded through the outgoing interface to the nexthop IP address

       B - Backup forwarding information

       A - Active forwarding information

 

NID        Tnl-Type Flag OutLabel Forwarding Info

--------------------------------------------------------------------------------

10         -        TA   -        2049

20         -        TA   -        2050

2048       LSP      NA   2025     GE3/0/2                  10.11.112.26

2049       LSP      NA   3024     GE3/0/2                  10.11.112.26

                    TB   3026     20

2050       LSP      NA   3025     GE3/0/1                  10.11.113.26

Table 2 Command output

Field	Description
Total NHLFE entries	Total number of NHLFE entries.
NID	NHLFE entry index.
Tnl-Type	Tunnel type: ·     LOCAL—Direct LSP tunnel. ·     LSP—Static LSP tunnel, or LSP tunnel signaled using LDP or BGP. ·     GRE—GRE tunnel. ·     - (a hyphen)—The tunnel type is invalid.
Flag	Forwarding flag: ·     T—Forwarded through a tunnel. ·     N—Forwarded through the outgoing interface to the next hop IP address. ·     B—Backup forwarding information. ·     A—Active forwarding information.
OutLabel	Outgoing label.
Forwarding Info	Forwarding information: ·     When the forwarding flag is N, the forwarding information records the outgoing interface and the next hop. ·     When the forwarding flag is T, the forwarding information records the NID.

 

display mpls interface

Use display mpls interface to display MPLS interface information, including the interface name, interface status, and interface MPLS MTU.

Syntax

display mpls interface [ interface-type interface-number ]

Views

Any view

Predefined user roles

network-admin

network-operator

mdc-admin

mdc-operator

Parameters

interface-type interface-number: Specifies an interface by the interface type and number. If you do not specify an interface, this command displays MPLS information for all MPLS-enabled interfaces.

Examples

# Display all MPLS interfaces.

<Sysname> display mpls interface

Interface               Status       MPLS MTU

GE3/0/1                 Up           1514

GE3/0/2                 Up           1514

The MPLS MTU of an interface is in bytes.

Related commands

·     mpls enable

·     mpls mtu

display mpls label

Use display mpls label to display MPLS label usage information.

Syntax

display mpls label { label-value1 [ to label-value2 ] | all }

Views

Any view

Predefined user roles

network-admin

network-operator

mdc-admin

mdc-operator

Parameters

label-value1: Specifies a label value in the range of 16 to 1048575. If used with the label-value2 argument, the label-value1 argument represents the start label of a label range.

to label-value2: Specifies the end label of the label range. The value range for the end label is 16 to 1048575. If you specify a label range by using the label-value1 argument and the to label-value2 option, this command displays usage information for the specified range of labels.

all: Specifies all labels.

Examples

# Display usage information for labels 900 through 902.

<Sysname> display mpls label 900 to 902

Label          Owner          State

900            -              Idle

901            -              Idle

902            LDP            Alloc

Table 3 Command output

Field	Description
Label	Label value.
Owner	Protocol that is using the label. Possible values include LDP, BGP, and L2VPN.
State	Usage state of the label: ·     Idle—The label is idle. ·     Alloc—The label has been allocated. ·     Pending—The label has been released but is still used by an LSP entry. ·     Inuse—The label has been allocated and used by an LSP entry.

 

display mpls lsp

Use display mpls lsp to display LSP information.

Syntax

display mpls lsp [ egress | in-label label-value | ingress | outgoing-interface interface-type interface-number | protocol { bgp | ldp | local | rsvp-te | static | static-cr } | transit ] [ vpn-instance vpn-instance-name ] [ ipv4-dest mask-length | ipv6 [ ipv6-dest prefix-length ] ] [ verbose ]

Views

Any view

Predefined user roles

network-admin

network-operator

mdc-admin

mdc-operator

Parameters

egress: Displays the LSPs taking the current LSR as the egress.

in-label label-value: Displays the LSPs using the specified label as the incoming label, in the range of 0 to 1048575.

ingress: Displays the LSPs taking the current LSR as the ingress.

outgoing-interface interface-type interface-number: Displays the LSPs using the specified interface as the outgoing interface. The interface-type interface-number argument specifies an interface by its type and number.

protocol: Displays the LSPs established by a specific protocol.

bgp: Displays BGP LSPs.

ldp: Displays LDP LSPs.

local: Displays the direct LSP.

rsvp-te: Displays CRLSPs established by RSVP-TE. The device does not support this keyword.

static: Displays static LSPs.

static-cr: Displays static CRLSPs. The device does not support this keyword.

transit: Displays the LSPs taking the current LSR as a transit LSR.

vpn-instance vpn-instance-name: Displays LSPs for the specified VPN. The vpn-instance-name is a case-sensitive string of 1 to 31 characters. If you do not specify this option, the command displays LSPs for the public network.

ipv4-dest mask-length: Displays the IPv4 LSP for an FEC specified by an IPv4 address and a mask length. The value range for the mask length is 0 to 32.

ipv6: Displays IPv6 LSP information. If you do not specify this keyword, the command displays IPv4 LSP information.

ipv6-dest prefix-length: Displays the IPv6 LSP for an FEC specified by an IPv6 address and a prefix length. The value range for the prefix length is 0 to 128.

verbose: Displays detailed LSP information. If you do not specify this keyword, the command displays brief LSP information.

Usage guidelines

If you do not specify any parameters, this command displays brief information about all LSPs. If you specify only the verbose keyword, this command displays detailed information about all LSPs.

Examples

# Display brief information about all IPv4 LSPs.

<Sysname> display mpls lsp

FEC                         Proto    In/Out Label    Interface/Out NHLFE

100.100.100.100/24          LDP      -/1049          Vlan20

Backup                               -/1050          Vlan21

100.100.100.10/24           LDP      -/1051          Vlan22

Backup                               -/1050          Vlan21

100.100.100.10/24           LDP      -/1049          Vlan30

101.100.100.10/24           LDP      1026/1049       Vlan20

102.100.100.10/24           LDP      1027/-          -

103.100.100.10/24           LDP      1028/1049       Tunnel10

110.100.100.20/24           BGP      -/1049          Vlan20

111.100.100.10/24           BGP      2028/1049       Vlan20

112.100.100.10/24           BGP      2029/-          Vlan20

113.100.100.10/24           BGP      2030/1049       NHLFE1500

114.100.100.10/24           BGP      2031/1050       Tunnel100

100.100.100.100             Local    -/-             Vlan20

101.101.101.101/32          Static   -/100           Vlan20

-                           Static   100/200         Vlan20

-                           Static   101/-           Vlan20

Table 4 Command output

Field	Description
FEC	Forwarding equivalence class: ·     IP address/mask—Classifies FECs by destination address. ·     IP address—Classifies FECs by next hop. ·     IP address/Out Label—Classifies FECs by next hop and outgoing label. ·     - (a hyphen)—The LSP is a static transit LSP or static egress LSP. ·     Backup—If the LSP is a backup LSP of the previous LSP, this field displays Backup.
Proto	Label distribution protocol: ·     LDP. ·     BGP. ·     Static. ·     Local—The LSP is a direct LSP.
In/Out Label	Incoming label/outgoing label.
Interface/Out NHLFE	Outgoing interface name or NHLFE entry index. NHLFEnumber specifies the outer LSP that carries the current LSP. The outer LSP is that matches the NHLFE entry with an NID of number.

 

# Display IPv6 LSP information.

<Sysname> display mpls lsp ipv6

FEC      : 100:100:100:100:100:100:100:100/128

Protocol : BGP      In-Label     : 2050

Out-Label: 10003    Out-Interface: Vlan10

BkLabel  : 10004    BkInterface  : Vlan20

Table 5 Command output

Field	Description
FEC	Forwarding equivalence class: ·     IP address/mask—Classifies FECs by destination address. ·     IP address—Classifies FECs by next hop. ·     IP address/Out Label—Classifies FECs by next hop and outgoing label. ·     - (a hyphen)—The LSP is a static transit LSP or static egress LSP.
Protocol	Label distribution protocol: ·     LDP. ·     BGP. ·     Static. ·     Local—Direct LSP.
BkLabel	Outgoing label of the backup LSP.
BkInterface	Outgoing interface of the backup LSP.

 

# Display detailed information about all LSPs.

<Sysname> display mpls lsp verbose

Destination  : 56.10.10.2

FEC          : 56.10.10.2/32

Protocol     : LDP

LSR Type     : Egress

Service      : Statistics

In-Label     : 1024       

State        : Active

Inbound Statistics:

  Octets    : 13000

  Packets   : 100

  Errors    : 0

  Discards  : 0

 

Destination  : 56.10.10.4

FEC          : 56.10.10.2/32

Protocol     : LDP

LSR Type     : Transit

Service      : Statistics

In-Label     : 1026

Inbound Statistics:

  Octets    : 10600

  Packets   : 100

  Errors    : 0

  Discards  : 0

Path ID      : 0x40000000.1

State        : Active

Out-Label    : 1800

Nexthop      : 10.1.1.2

Out-Interface: Vlan10

BkLabel      : 1900

BkNexthop    : 20.1.1.2

BkInterface   : Vlan20

Outbound Statistics:

  Octets    : 12600

  Packets   : 100

  Errors    : 0

  Discards  : 0

 

Destination  : 56.10.10.4

FEC          : 56.10.10.2/32

Protocol     : LDP

LSR Type     : Ingress

Service      : -      

NHLFE ID     : 2000

State        : Active

Out-Label    : 1800

Nexthop      : 10.1.1.2

Out-Interface: Vlan10

Table 6 Command output

Field	Description
Destination	LSP destination address.
FEC	Forwarding equivalence class: ·     IP address/mask—Classifies FECs by destination address. ·     IP address—Classifies FECs by next hop. ·     IP address/Out Label—Classifies FECs by next hop and outgoing label. ·     - (a hyphen)—The LSP is a static transit LSP or static egress LSP.
Protocol	Label distribution protocol: ·     LDP. ·     BGP. ·     Static. ·     Local—Direct LSP.
LSR Type	LSR type: ·     Ingress—The current LSR is the ingress node of the LSP. ·     Transit—The current LSR is a transit node of the LSP. ·     Egress—The current LSR is the egress node of the LSP.
Service	Service deployed on the LSP. The service can only be Statistics, which indicates the MPLS forwarding statistics function.
Path ID	Forwarding path. The value is in the format of 0xnn.m, where nn represents the NHLFE group ID of the outer LSPs that carry the current LSP, and m represents the sequence number of the equivalence path.
NHLFE ID	NHLFE entry index.
State	LSP state: ·     Active—The LSP is in use. ·     Inactive—The LSP is idle.
Inbound Statistics	MPLS forwarding statistics in inbound direction: ·     Octets—Number of received octets. ·     Packets—Number of received packets. ·     Errors—Number of received error packets. ·     Discards—Number of discarded packets.
BkLabel	Outgoing label of the backup LSP.
BkNexthop	Next hop address of the backup LSP.
BkInterface	Outgoing interface of the backup LSP.
Outbound Statistics	MPLS forwarding statistics in outbound direction: ·     Octets—Number of sent octets. ·     Packets—Number of sent packets. ·     Errors—Number of error packets. ·     Discards—Number of discarded packets.

 

Related commands

display mpls lsp statistics

display mpls lsp statistics

Use display mpls lsp statistics to display LSP statistics.

Syntax

display mpls lsp statistics

Views

Any view

Predefined user roles

network-admin

network-operator

mdc-admin

mdc-operator

Examples

# Display LSP statistics.

<Sysname> display mpls lsp statistics

LSP Type      Ingress/Transit/Egress  Active

Static LSP    0/0/0                   0/0/0

LDP LSP       2/2/1                   2/2/1

BGP LSP       0/0/0                   0/0/0

Local LSP     2/0/0                   2/0/0

-----------------------------------------------------

Total         4/2/1                   4/2/1

 

Table 7 Command output

Field	Description
LSP Type	LSP types: ·     Static LSP. ·     LDP LSP. ·     Local LSP (direct LSP). ·     BGP LSP.
Total	Total number of LSPs.
Ingress	Number of LSPs that take the local device as the ingress node.
Transit	Number of LSPs that take the local device as a transit node.
Egress	Number of LSPs that take the local device as the egress node.
Active	Number of active LSPs of a specific type.

 

display mpls nib

Use display mpls nib to display MPLS Nexthop Information Base (NIB) information.

Syntax

display mpls nib [ nib-id ]

Views

Any view

Predefined user roles

network-admin

network-operator

mdc-admin

mdc-operator

Parameters

nib-id: Specifies a next hop ID in the range of 1 to FFFFFFFFFFFFFFFE. If you do not specify a next hop, this command displays information about all MPLS next hops.

Examples

# Display information about all MPLS next hops.

<Sysname> display mpls nib

NIB ID: 0x40000000

  Users: 1

  Status: Active

  ECMP number: 1

      Outgoing NHLFE ID: 1024

      Backup outgoing NHLFE ID: 1027

Table 8 Command output

Field	Description
NIB ID	ID of the next hop.
Users	Number of ILM entries that use this next hop.
Status	Next hop status: ·     Active—The next hop is active. ·     Dummy—The next hop is inactive.
ECMP number	Number of equal-cost NHLFE entries.
Outgoing NHLFE ID	ID of the NHLFE entry to which the next hop corresponds.
Backup outgoing NHLFE ID	ID of the backup NHLFE entry.

 

display mpls nid

Use display mpls nid to display usage information for dynamic NIDs.

Syntax

display mpls nid [ nid-value1 [ to nid-value2 ] ]

Views

Any view

Predefined user roles

network-admin

network-operator

mdc-admin

mdc-operator

Parameters

nid-value1: Specifies an NID in the range of 0 to 65535. If used with the nid-value2 argument, the nid-value1 argument represents the start NID of an NID range.

to nid-value2: Specifies the end NID of the NID range. The value range for the end NID is 0 to 65535. If you specify an NID range by using the nid-value1 argument and the to nid-value2 option, this command displays usage information for the specified range of NIDs.

Usage guidelines

NIDs are 32-bit binary numbers. They include fixed NIDs and dynamic NIDs.

·     Fixed NIDs—Generated for tunnel interfaces. The highest four bits are a value other than 0000.

·     Dynamic NIDs—NIDs except fixed NIDs. The highest four bits are 0s.

If you do not specify any parameters, this command displays usage information for all dynamic NIDs.

Examples

# Display usage information for NIDs 1028 through 1500.

<Sysname> display mpls nid 1028 to 1500

NID alloc state: '.' means not used, '$' means used

1028   :...$.... ........ ........ ........  ........ ........ ........ ........

1092   :........ ........ ........ ........  ........ ........ ........ ........

1156   :........ ........ ........ ........  ........ ........ ........ ........

1220   :........ ........ ........ ........  ........ ........ ........ ........

1284   :........ ........ ........ ........  ........ ........ ........ ........

1348   :........ ........ ........ ........  ........ ........ ........ ........

1412   :........ ........ ........ ........  ........ ........ ........ ........

1476   :........ ........ ........ .

display mpls summary

Use display mpls summary to display MPLS summary information.

Syntax

display mpls summary

Views

Any view

Predefined user roles

network-admin

network-operator

mdc-admin

mdc-operator

Examples

# Display MPLS summary information.

<Sysname> display mpls summary

Memory State     : Normal

MPLS LSR ID      : 1.1.1.1

Egress Label Type: Implicit-null

Labels:

  Range           Idle

  16-1023         0

  1024-13311      11008

  65536-69631     4096

  131072-139263   8192

Protocols:

  Type            State

  LDP             Normal

  BGP             Normal

  Static          Normal

  L2VPN           Normal

Table 9 Command output

Field	Description
Memory State	Memory state: ·     Normal—The memory is normal. ·     Minor—The memory has a minor alarm. ·     Severe—The memory has a severe alarm. ·     Critical—The memory has a critical alarm.
Egress Label Type	Label type that the egress assigns to the penultimate hop: ·     Implicit-null. ·     Explicit-null.
Labels	Label information.
Range	Label range.
Idle	Number of idle labels in the label range.
Protocols	Running label distribution protocols and the related information.
Type	Protocol type: LDP, BGP, Static, or L2VPN.
State	Label distribution protocol running status: ·     Normal. ·     Recover—The protocol is in the GR process.

 

mpls enable

Use mpls enable to enable MPLS on an interface.

Use undo mpls enable to disable MPLS on an interface.

Syntax

mpls enable

undo mpls enable

Default

MPLS is disabled on an interface.

Views

Interface view

Predefined user roles

network-admin

mdc-admin

Usage guidelines

Execute this command on all interfaces that must perform MPLS forwarding.

Examples

# Enable MPLS on interface VLAN-interface 2.

<Sysname> System-view

[Sysname] interface vlan-interface 2

[Sysname-Vlan-interface2] mpls enable

Related commands

display mpls interface

mpls label advertise

Use mpls label advertise to specify the type of label the egress will advertise to the penultimate hop.

Use undo mpls label advertise to restore the default.

Syntax

mpls label advertise { explicit-null | implicit-null }

undo mpls label advertise

Default

As an egress, the device advertises an implicit null label to the penultimate hop.

Views

System view

Predefined user roles

network-admin

mdc-admin

Parameters

explicit-null: Specifies the egress to advertise an explicit null label of 0 to the penultimate hop.

implicit-null: Specifies the egress to advertise an implicit null label of 3 to the penultimate hop.

Usage guidelines

If the penultimate hop supports PHP, H3C recommends that you configure the egress to advertise an implicit null label to the penultimate hop. If you want to simplify packet forwarding on the egress but keep labels to determine QoS policies, configure the egress to advertise an explicit null label to the penultimate hop.

As a penultimate hop, the device accepts the implicit null label or explicit null label advertised by the egress device.

For LDP LSPs, the mpls label advertise command triggers LDP to delete the LSPs established before the command is executed and re-establishes new LSPs.

For BGP LSPs, the mpls label advertise command takes effect only on the BGP LSPs established after the command is executed. To apply the new setting to BGP LSPs established before the command is executed, delete the routes corresponding to the BGP LSPs, and then redistribute the routes.

For CRLSPs established by using RSVP, the mpls label advertise command takes effect only on the CRLSPs established after the command is executed. To apply the new setting to CRLSPs established before the command is executed, delete the CRLSPs and re-establish them.

Examples

# Configure the egress device to advertise an explicit null label to the penultimate hop.

<Sysname> system-view

[Sysname] mpls label advertise explicit-null

Related commands

reset mpls ldp

mpls lsr-id

Use mpls lsr-id to configure an LSR ID for the local LSR.

Use undo mpls lsr-id to delete the LSR ID of the local LSR.

Syntax

mpls lsr-id lsr-id

undo mpls lsr-id

Default

An LSR has no LSR ID.

Views

System view

Predefined user roles

network-admin

mdc-admin

Parameters

lsr-id: Specifies an ID for identifying the LSR, in dotted decimal notation.

Usage guidelines

H3C recommends that you use the address of a loopback interface on the LSR as the LSR ID.

Examples

# Configure the LSR ID as 3.3.3.3 for the local node.

<Sysname> system-view

[Sysname] mpls lsr-id 3.3.3.3

Related commands

lsr-id

mpls mtu

Use mpls mtu to set the MPLS MTU for an interface.

Use undo mpls mtu to restore the default.

Syntax

mpls mtu value

undo mpls mtu

Default

The MPLS MTU of an interface is not configured. Fragmentation for MPLS packets is based on the MTU of the interface, and the length of a fragment does not include that of the MPLS label. Thus, after an MPLS label is added into a fragment, the length of the MPLS fragment might exceed the interface MTU.

Views

Interface view

Predefined user roles

network-admin

mdc-admin

Parameters

value: Specifies the MPLS MTU of the interface, in the range of 46 to 65535 bytes.

Usage guidelines

This command is effective only when MPLS is enabled on the interface.

If the MPLS MTU is larger than the interface MTU, data forwarding might fail.

Examples

# Set the MPLS MTU of interface VLAN-interface 2 to 1000 bytes.

<Sysname> system-view

[Sysname] interface vlan-interface 2

[Sysname-Vlan-interface2] mpls enable

[Sysname-Vlan-interface2] mpls mtu 1000

Related commands

display mpls interface

mpls ttl expiration enable

Use mpls ttl expiration enable to enable the sending of MPLS TTL-expired messages.

Use undo mpls ttl expiration enable to disable the sending of MPLS TTL-expired messages.

Syntax

mpls ttl expiration enable

undo mpls ttl expiration enable

Default

The MPLS TTL-expired messages sending function is enabled.

Views

System view

Predefined user roles

network-admin

mdc-admin

Usage guidelines

The mpls ttl expiration enable command enables an LSR to generate an ICMP TTL-expired message upon receiving an MPLS packet with TTL being 1.

·     If the MPLS packet has only one label, the LSR sends the ICMP TTL-expired message back to the source through IP routing.

·     If the MPLS packet has multiple labels, the LSR forwards the ICMP TTL-expired message along the LSP of the MPLS packet to the egress, which then sends the message back to the source.

Examples

# Disable the MPLS TTL-expired messages sending function.

<Sysname> system-view

[Sysname] undo mpls ttl expiration enable

mpls ttl propagate

Use mpls ttl propagate to enable TTL propagation.

Use undo mpls ttl propagate to disable TTL propagation.

Syntax

mpls ttl propagate { public | vpn }

undo mpls ttl propagate { public | vpn }

Default

TTL propagation is enabled for public network packets and disabled for VPN packets.

Views

System view

Predefined user roles

network-admin

mdc-admin

Parameters

public: Specifies public network packets.

vpn: Specifies VPN packets.

Usage guidelines

When TTL propagation is enabled, MPLS performs the following operations:

·     Copies the IP TTL to the label TTL for packets entering the MPLS network.

·     Copies the label TTL to the IP TTL for packets leaving the MPLS network.

If you enable TTL propagation on both the ingress and egress, the IP tracert facility can show the real path in the MPLS network.

When TTL propagation is disabled, MPLS performs the following operations:

·     Sets the label TTL to 255 for packets entering the MPLS network.

·     Pops the label for packets leaving the MPLS network, without copying the label TTL value to the IP TTL.

The IP tracert facility cannot show the real path in the MPLS network.

Within an MPLS network, TTL is always copied between the labels of an MPLS packet. The mpls ttl propagate command affects only the propagation between IP TTL and label TTL.

H3C recommends that you set the same TTL processing mode on all LSRs of an LSP.

To enable TTL propagation for a VPN, you must enable it on all PE devices in the VPN. This allows you to obtain the same traceroute result (hop count) from those PEs.

Examples

# Enable TTL propagation for VPN packets.

<Sysname> system-view

[Sysname] mpls ttl propagate vpn

snmp-agent trap enable mpls

Use snmp-agent trap enable mpls to enable SNMP notifications for MPLS.

Use undo snmp-agent trap enable mpls to disable SNMP notifications for MPLS.

Syntax

snmp-agent trap enable mpls

undo snmp-agent trap enable mpls

Default

SNMP notifications for MPLS are enabled.

Views

System view

Predefined user roles

network-admin

mdc-admin

Usage guidelines

This command enables MPLS to generate SNMP notifications. The generated SNMP notifications are sent to the SNMP module.

For more information about SNMP notifications, see Network Management and Monitoring Configuration Guide.

Examples

# Enable SNMP notifications for MPLS.

<Sysname> system-view

[Sysname] snmp-agent trap enable mpls