Deployment Guide

● A command has been introduced to partition the LPM to support provisioning of IPv6 /65 to /128 route prefixes.
To support /65 – /128 IPv6 route prefix 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 effect after reboot of the box. This is because the SDK does the LPM partitioning during the chip
initialization.
The longest prefix match (LPM) table on the system supports different types of prefixes 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 Prefixes)
2. IPv6 64-bit LPM table (Holds IPv6 Prefixes less than /65 Prefix Length)
3. IPv6 128-bit LPM table (Holds IPv6 Prefixes greater than /64 Prefix 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
prefix-length) or 3K IPv6 route entries (greater than /64 prefix-length). You can configure the LPM table with one of the
following partitions to support the IPv4 and IPv6 prefix 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.
The platforms uses only IPv6 /0 – 0/64 prefix route entries. Support for /0 – /128 IPv6 prefix route entries is available,
although they are not utilized. A total of eight pools or regions are present with each region containing 1024 210-bit entries
(supports up to 0/64 prefix). To support up to /128 prefixes, you must use 2 banks (410-bit entries). It is necessary to partition
the LPM.
The optimized booting functionality does not use Openflow and therefore SDN support is not available. LPM partitioning might
have a slight impact on the number of SDN-programmed L3 entries because the LPM space becomes reduced.
IPv6 Header Fields
The 40 bytes of the IPv6 header are ordered, as shown in the following illustration.
Figure 60. IPv6 Header Fields
IPv6 Routing
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