To configure the
range of local labels available for use with Multiprotocol Label Switching
(MPLS) applications on packet interfaces, use thempls label range command in global configuration
mode. To revert to the platform defaults, use the
no form of this
command.
mpls label range minimum-value maximum-value [static minimum-static-value maximum-static-value]
no mpls label range
Syntax Description
|
minimum-value
|
The value
of the smallest label allowed in the label space. The default is 16.
|
|
maximum-value
|
The value
of the largest label allowed in the label space. The default is
platform-dependent.
|
|
static
|
(Optional) Reserves a block of local labels for static label assignments. If
you omit the
static keyword
and the
minimum-static-value
maximum-static-value arguments, no labels are
reserved for static assignment.
|
|
minimum-static-value
|
(Optional) The minimum value for static label assignments. There is no default
value.
|
|
maximum-static-value
|
(Optional) The maximum value for static label assignments. There is no default
value.
|
Command Default
The platform’s
default values are used.
Command Modes
Global configuration
Command History
|
Release
|
Modification
|
|
Cisco IOS
XE Denali 16.3.1
|
This
command was introduced.
|
Usage Guidelines
The labels 0
through 15 are reserved by the IETF (see RFC 3032, MPLS Label Stack Encoding,
for details) and cannot be included in the range specified in the
mpls label
range command. If you enter a 0 in the command, you will get a
message that indicates that the command is an unrecognized command.
The label range
defined by thempls label
range command is used by all MPLS applications that allocate
local labels (for dynamic label switching, MPLS traffic engineering, MPLS
Virtual Private Networks (VPNs), and so on).
You can use label
distribution protocols, such as Label Distribution Protocol (LDP), to reserve a
generic range of labels from 16 through 1048575 for dynamic assignment.
You specify the
optional
static keyword,
to reserve labels for static assignment. The MPLS Static Labels feature
requires that you configure a range of labels for static assignment. You can
configure static bindings only from the current static range. If the static
range is not configured or is exhausted, then you cannot configure static
bindings.
The range of label
values is 16 to 4096. The maximum value defaults to 4096. You can split for
static label space between say 16 to 100 and for dynamic label space between
101 to 4096.
The upper and
lower minimum static label values are displayed in the help line. For example,
if you configure the dynamic label with a minimum value of 16 and a maximum
value of 100, the help lines display as follows:
Switch(config)# mpls label range 16 100 static ?
<100> Upper Minimum static label value
<16> Lower Minimum static label value
Reserved Label Range --> 0 to 15
Available Label Range --> 16 to 4096
Static Label Range --> 16 to 100
Dynamic Label Range --> 101 to 4096
In this example,
you can configure a static range from 16 to 100.
If the lower
minimum static label space is not available, the lower minimum is not displayed
in the help line. For example:
Switch(config)# mpls label range 16 100 static ?
<16-100> static label value range
Examples
The following
example shows how to configure the size of the local label space. In this
example, the minimum static value is set to 200, and the maximum static value
is set to 4000.
Switch# configure terminal
Enter configuration commands, one per line. End with CNTL/Z.
Switch(config)# mpls label range 200 4000
Switch(config)#
If you had
specified a new range that overlaps the current range (for example, the new
range of the minimum static value set to 16 and the maximum static value set to
1000), then the new range takes effect immediately.
The following
example show how to configure a dynamic local label space with a minimum static
value set to 100 and the maximum static value set to 1000 and a static label
space with a minimum static value set to 16 and a maximum static value set to
99:
Switch(config)# mpls label range 100 1000 static 16 99
Switch(config)#
In the following
output, the
show mpls label
range command, executed after a reload, shows that the configured
range is now in effect:
Switch# show mpls label range
Downstream label pool: Min/Max label: 100/1000
Range for static labels: Min/Max/Number: 16/99
The following
example shows how to restore the label range to its default value:
Switch# configure terminal
Enter configuration commands, one per line. End with CNTL/Z.
Switch(config)# no mpls label range
Switch(config)# end
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