Service Manual

Dell Networking OS manipulation of IPv6 stateless autoconguration supports the router side only. Neighbor discovery (ND)
messages are advertised so the neighbor can use this information to auto-congure its address. However, received ND messages are
not used to create an IPv6 address.
NOTE: Inconsistencies in router advertisement values between routers are logged per RFC 4861. The values checked for
consistency include:
• Cur Hop limit
• M and O ags
• Reachable time
• Retrans timer
• MTU options
• Preferred and valid lifetime values for the same prex
Only management ports support stateless auto-conguration as a host.
The router redirect functionality in the neighbor discovery protocol (NDP) is similar to IPv4 router redirect messages. NDP uses
ICMPv6 redirect messages (Type 137) to inform nodes that a better router exists on the link.
IPv6 Headers
The IPv6 header has a xed length of 40 bytes. This xed length provides 16 bytes each for source and destination information and 8
bytes for general header information.
The IPv6 header includes the following elds:
• Version (4 bits)
• Trac Class (8 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 dened in the Next Header eld of the
preceding IPv6 header.
Longest Prex Match (LPM) Table and IPv6 /65 – /128 support
Two partitions are available.
• Partition I with IPv6 /65 – /128 route prex. Doesn’t support IPv4 entries in the current release.
• Partition II with IPv6 0/0 – /64 route prex and IPv4 0/0 -0/32 route prex entries.
• Number of entries in Partition II will be reduced based on the number of entries congured in Partition I.
• Partitioning will be applied well before the system initialization. This will be done using the NVRAM.
• Dell Networking OS provides CLI for enabling the partition. Conguration will be stored in NVRAM when the operator saves the
conguration.
• Partition will take eect only after the switch reboot. During the reboot Dell Networking OS reads the partition conguration
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 prexes.
To support /65 – /128 IPv6 route prex entries, Dell Networking OS needs to be programmed with /65 - /128 bit IPv6 support on
S6000 platform. The number of entries as well needs to be explicitly programmed. This number can be1K, 2K, or 3K granularity.
IPv6 Routing
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