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Cisco 7600 Series Router Cisco IOS Software Configuration Guide, Release 12.2SX
OL-4266-08
Chapter 24 Configuring PFC3BXL and PFC3B Mode Multiprotocol Label Switching
PFC3BXL and PFC3B Mode MPLS Label Switching
Configuring MPLS
For information about configuring MPLS, see the
Multiprotocol Label Switching on Cisco Routers
publication at the following URL:
http://www.cisco.com/en/US/docs/ios/12_2/switch/configuration/guide/xcftagc_ps1835_TSD_Product
s_Configuration_Guide_Chapter.html
MPLS Per-Label Load Balancing
The following sections provide information on basic MPLS, MLPS Layer 2 VPN, and MPLS Layer 3
VPN load balancing.
Basic MPLS Load Balancing
The maximum number of load balancing paths is 8. The PFC3BXL or PFC3B forwards MPLS labeled
packets without explicit configuration. If the packet has three labels or less and the underlying packet is
IPv4, then the PFC3BXL or PFC3B uses the source and destination IPv4 address. If the underlying
packet is not IPv4 or more than three labels are present, the PFC3BXL or PFC3B parses down as deep
as the fifth or lowest label and uses it for hashing.
MPLS Layer 2 VPN Load Balancing
Load balancing is based on the VC label in the MPLS core if the first nibble of the MAC address in the
customer Ethernet frame is not 4.
Note
Load balancing is not supported at the ingress PE for Layer 2 VPNs.
MPLS Layer 3 VPN Load Balancing
MPLS Layer 3 VPN load balancing is similar to basic MPLS load balancing. For more information, see
the
“Basic MPLS Load Balancing” section on page 24-8
.
MPLS Configuration Examples
The following is an example of a basic MPLS configuration:
*****
Basic MPLS
*****
IP ingress interface:
Router#
mpls label protocol ldp
interface GigabitEthernet6/2
ip address 75.0.77.1 255.255.255.0
media-type rj45
speed 1000
end