Setup Guide

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 55. IPv6 Header Fields
Version (4 bits)
The Version field always contains the number 6, referring to the packet’s IP version.
Traffic Class (8 bits)
The Traffic Class field deals with any data that needs special handling. These bits define the packet priority and are defined by the packet
Source. Sending and forwarding routers use this field to identify different IPv6 classes and priorities. Routers understand the priority
settings and handle them appropriately during conditions of congestion.
Flow Label (20 bits)
The Flow Label field identifies packets requiring special treatment in order to manage real-time data traffic.
The sending router can label sequences of IPv6 packets so that forwarding routers can process packets within the same flow without
needing to reprocess each packet’s header separately.
NOTE:
All packets in the flow must have the same source and destination addresses.
406 IPv6 Routing