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Applications for CAM Profiling
The following describes link aggregation group (LAG) hashing.
LAG Hashing
Dell Networking OS includes a CAM profile and microcode that treats MPLS packets as non-IP packets. Normally, switching and
LAG hashing is based on source and destination MAC addresses. Alternatively, you can base LAG hashing for MPLS packets on
source and destination IP addresses. This type of hashing is allowed for MPLS packets with five labels or less.
MPLS packets are treated as follows:
● When MPLS IP packets are received, Dell Networking OS looks up to five labels deep for the IP header.
● When an IP header is present, hashing is based on IP three tuples (source IP address, destination IP address, and IP
protocol).
● If an IP header is not found after the fifth label, hashing is based on the MPLS labels.
● If the packet has more than five MPLS labels, hashing is based on the source and destination MAC address.
To enable this type of hashing, use the default CAM profile with the microcode lag-hash-mpls.
LAG Hashing Based on Bidirectional Flow
To hash LAG packets such that both directions of a bidirectional flow (for example, VoIP or P2P file sharing) are mapped to the
same output link in the LAG bundle, use the default CAM profile with the microcode lag-hash-align.
Unified Forwarding Table (UFT) Modes
Unified Forwarding Table (UFT) consolidates the resources of several search tables (Layer 2, Layer 3 Hosts, and Layer 3 Route
[Longest Prefix Match — LPM]) into a single flexible resource. Dell EMC Networking OS supports several UFT modes to extract
the forwarding tables, as required. By default, Dell EMC Networking OS initializes the table sizes to UFT mode 2 profile, since it
provides a reasonable shared memory for all the tables. The other supported UFT modes are scaled-l3–hosts (UFT mode 3) and
scaled-l3–routes (UFT mode 4).
Configuring UFT Modes
To configure the Unified Forwarding Table (UFT) modes, follow these steps.
1. Select a mode to initialize the maximum scalability size for L2 MAC table or L3 Host table or L3 Route table.
CONFIGURATION
hardware forwarding-table mode
DellEMC(conf)#hardware forwarding-table mode ?
scaled-l3-hosts Forwarding table mode for scaling L3 host entries
scaled-l3-routes Forwarding table mode for scaling L3 route entries
DellEMC(conf)#
DellEMC(conf)#hardware forwarding-table mode scaled-l3-hosts
Hardware forwarding-table mode is changed. Save the configuration and reload to take
effect.
DellEMC(conf)#end
DellEMC#write mem
!
01:13:36: %STKUNIT0-M:CP %FILEMGR-5-FILESAVED: Copied running-config to startup-
config in flash by default
DellEMC(conf)#
DellEMC(conf)#end
DellEMC#01:13:44: %STKUNIT0-M:CP %SYS-5-CONFIG_I: Configured from console
DellEMC#
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Content Addressable Memory (CAM)