Users Guide

150| IPv6 Support Dell Networking W-Series ArubaOS 6.5.x| User Guide
To view user entries for IPv6 clients using the command line interface, use the show user-table command in
enable mode. To delete a user entry for an IPv6 client, access the CLI in config mode and use the aaa ipv6
user delete command. For example:
(host)(config) #aaa ipv6 user delete 2002:d81f:f9f0:1000:e409:9331:1d27:ef44
Understanding User Roles
An IPv6 user or a client can inherit the corresponding IPv4 roles. A user or client entry on the user table will
contain the user or client’s IPv4 and IPv6 entries. After captive-portal authentication, a IPv4 client can acquire a
different role. This role is also updated on the client’s IPv6 entry in the user table.
Viewing Datapath Statistics for IPv6 Sessions
To view datapath session statistics for individual IPv6 sessions, access the command-line interface in enable
mode and issue the command show datapath session ipv6. To display the user entries in the datapath,
access the command-line interface in enable mode, and issue the command show datapath user ipv6. For
details on each of these commands and the output they display, refer to the Dell Networking W-Series ArubaOS
Command Line Reference Guide.
Understanding IPv6 Exceptions and Best Practices
The IPv6 best practices are provided below:
l Ensure that you enable IPv6 globally.
l The uplink port must be trusted. This is the same behavior as IPv4.
l Ensure that the validuser session ACL does not block IPv6 traffic.
l There must not be any ACLs that drop ICMPv6 or DHCPv6 traffic. It is acceptable to drop DHCPv6 traffic if
the deployment uses Stateless Address Auto Configuration (SLAAC) only.
l If an external device provides RA:
n It is not recommended to advertise too many prefixes in RA.
n The controller supports a maximum of four IPv6 user entries in the user table. If a client uses more than
four IPv6 addresses at a time, the user table is refreshed with the latest four active entries without
disrupting the traffic flow. However, this may have some performance impact.
l Enable BCMC Optimization under interface VLAN to drop any random IPv6 multicast traffic. DHCPv6, ND,
NS, and RA traffic are not dropped when you enable this option.
It is recommended to enable BCMC Optimization only if mDNS traffic is not used in the network, as mDNS traffic
gets dropped if this option is enabled.
l It is not recommended to enable preemption on the master redundancy model. If preemption is disabled
and if there is a failover, the new primary controller remains the primary controller even when the original
master is online again. The new primary controller does not revert to its original state unless forced by the
administrator. Disabling preemption prevents the master from “flapping” between two controllers and
allows the administrator to investigate the cause of the outage.
l While selecting a source address, the number of common bits between each source address in the list, is
checked from the left most bit. This is followed by selection of the source address that has the maximum
number of matching bits with the destination address. If more than one source addresses has the same
number of matching bits with the destination address, the kernel selects that source address that is most
recently configured on the system. It is essential that the administrator/user configures the network
appropriately, if a particular VLAN interface needs to be selected as the source. For example, in case of