HPE FlexNetwork 5510 HI Series, Руководство по настройке Mpls

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5
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One LFIB lookup and one FIB lookup (if the packet has only one label).
The penultimate hop popping (PHP) feature can pop the label at the penultimate node, so the egress
node only performs one table lookup.
A PHP-capable egress node sends the penultimate node an implicit null label of 3. This label never
appears in the label stack of packets. If an incoming packet matches an LFIB entry comprising the
implicit null label, the penultimate node pops the top label of the packet and forwards the packet to
the egress LSR. The egress LSR directly forwards the packet.
Sometimes, the egress node must use the TC field in the label to perform QoS. To keep the TC
information, you can configure the egress node to send the penultimate node an explicit null label of
0. If an incoming packet matches an LFIB entry comprising the explicit null label, the penultimate hop
replaces the value of the top label with value 0, and forwards the packet to the egress node. The
egress node gets the TC information, pops the label of the packet, and forwards the packet.
Protocols and standards
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RFC 3031, Multiprotocol Label Switching Architecture
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RFC 3032, MPLS Label Stack Encoding
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RFC 5462, Multiprotocol Label Switching (MPLS) Label Stack Entry: "EXP" Field Renamed to
"Traffic Class" Field
MPLS configuration task list
Tasks at a glance
(Required.) Enabling MPLS
(Optional.) Configuring MPLS MTU
(Optional.) Specifying the label type advertised by egress
(Optional.) Configuring TTL propagation
(Optional.) Enabling sending of MPLS TTL-expired messages
(Optional.) Enabling MPLS forwarding statistics
(Optional.) Enabling SNMP notifications for MPLS
Enabling MPLS
Before you enable MPLS, perform the following tasks:
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Configure link layer protocols to ensure connectivity at the link layer.
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Configure IP addresses for interfaces to ensure IP connectivity between neighboring nodes.
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Configure static routes or an IGP protocol to ensure IP connectivity among LSRs.
To enable MPLS:
Step Command Remarks
1. Enter system view.
system-view N/A
2. Configure an LSR ID for the
local node.
mpls lsr-id lsr-id
By default, no LSR ID is configured.
An LSR ID must be unique in an
MPLS network and in IP address