Setup Guide
• Flow Label (20 bits)
• Payload Length (16 bits)
• Next Header (8 bits)
• Hop Limit (8 bits)
• Source Address (128 bits)
• Destination Address (128 bits)
IPv6 provides for extension headers. Extension headers are used only if necessary. There can be no extension headers, one extension
header or more than one extension header in an IPv6 packet. Extension headers are dened in the Next Header eld of the preceding IPv6
header.
Longest Prex Match (LPM) Table and IPv6 /65 – /128
support
Two partitions are available.
• Partition I with IPv6 /65 – /128 route prex. Doesn’t support IPv4 entries in the current release.
• Partition II with IPv6 0/0 – /64 route prex and IPv4 0/0 -0/32 route prex entries.
• Number of entries in Partition II will be reduced based on the number of entries congured in Partition I.
• Partitioning will be applied well before the system initialization. This will be done using the NVRAM.
• Dell EMC Networking OS provides CLI for enabling the partition. Conguration will be stored in NVRAM when the operator saves the
conguration.
• Partition will take eect only after the switch reboot. During the reboot Dell EMC Networking OS reads the partition conguration from
NVRAM and uses the same for partitioning the LPM.
• A command has been introduced to partition the LPM to support provisioning of IPv6 /65 to /128 route prexes.
To support /65 – /128 IPv6 route prex entries, Dell EMC Networking OS needs to be programmed with /65 - /128 bit IPv6 support. The
number of entries as well needs to be explicitly programmed. This number can be1K, 2K, or 3K granularity.
On the system, for IPv6 /65 to /128 will consume the same storage banks which is used by the L3_DEFIP table. Once the IPv6 128 bit is
enabled, number of entries in L3_DEFIP will be reduced.
LPM partitioning will take eect after reboot of the box. This is because the SDK does the LPM partitioning during the chip initialization.
The longest prex match (LPM) table on the system supports dierent types of prexes for IPv6 and IPv4. The route table, also called the
LPM table, is divided into the following three logical tables:
1 IPv4 32-bit LPM table (Holds IPv4 Prexes)
2 IPv6 64-bit LPM table (Holds IPv6 Prexes less than /65 Prex Length)
3 IPv6 128-bit LPM table (Holds IPv6 Prexes greater than /64 Prex Length)
The LPM table, which is 8K in size, is a dedicated table. It comprises eight ternary content addressable memory (CAM) blocks, with each
block being 1K in size. The table can contain 16KIPv4 route entries or 8K IPv6 route entries (less than /65 prex-length) or 3K IPv6 route
entries (greater than /64 prex-length). You can congure the LPM table with one of the following partitions to support the IPv4 and IPv6
prex route entries:
• Partition 1: IPv6 128-bit LPM entries can be stored in this partition. IPv4 and 64-bit IPv6 entries cannot be saved in this partition.
• Partition 2: IPv4 LPM and 64-bit IPv6 LPM entries can be stored in this partition.
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IPv6 Routing










