Service Manual

On the S6000 platform, 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 eect after reboot of the box. This is because the SDK does the LPM partitioning during the chip
initialization.
The longest prex match (LPM) table on the S6000 platform supports dierent types of prexes 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 Prexes)
2. IPv6 64-bit LPM table (Holds IPv6 Prexes less than /65 Prex Length)
3. IPv6 128-bit LPM table (Holds IPv6 Prexes greater than /64 Prex 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 prex-length) or 3K
IPv6 route entries (greater than /64 prex-length). You can congure the LPM table with one of the following partitions to support
the IPv4 and IPv6 prex 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 (S6000) useS presently only IPv6 /0 – 0/64 prex route entries. Support for /0 – /128 IPv6 prex 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 prex). To support up to /128 prexes, you must use 2 banks (410-bit entries). It is necessary to partition the
LPM.
The optimized booting functionality does not use Openow 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 47. IPv6 Header Fields
Version (4 bits)
The Version eld always contains the number 6, referring to the packet’s IP version.
Trac Class (8 bits)
The Trac Class eld deals with any data that needs special handling. These bits dene the packet priority and are dened by the
packet Source. Sending and forwarding routers use this eld to identify dierent IPv6 classes and priorities. Routers understand the
priority settings and handle them appropriately during conditions of congestion.
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IPv6 Routing