Install guide

Software Release 2.6.4 9
Software Release 2.6.4
C613-10404-00 REV A
How Stacking Works
The Stacking feature centralises management by distributing and maintaining
system-wide information about stack members. It also:
■ Synchronises and propagates information about individual stack members
■ Propagates CLI and GUI commands
■ Manages responses and acknowledgements
■ Synchronises the stack configuration file
Switches have individual host IDs, which you set, so that they know which
device they are in the stack. Stacks have unique stack IDs, which you also set,
so that switches know to which stack they belong. Stack IDs are essential when
you have multiple stacks.
Stacked switches communicate with each other over a Stacking interface,
which is a user-defined virtual interface such as a VLAN. Ports in the Stacking
VLAN should be added as tagged VLAN ports to data VLANs. This ensures
that the Stacking VLAN carries user data.
For more information, see the Stacking chapter in the Software Reference.
ICMP Router Discovery Advertisements
This release supports all of RFC 1256, ICMP Router Discovery Messages, 1991 as
it applies to routers. If this feature is configured, the switch sends router
advertisements periodically and in response to router solicitations. It does not
support the Host Specification section of this RFC.
Before an IP host can send an IP packet, it has to know the IP address of a
neighbouring router that can forward it to its destination. ICMP Router
Discovery messages allow routers to automatically advertise themselves to
hosts. Other methods either require someone to manually keep these addresses
up to date, or require DHCP to send the router address, or require the hosts to
be able to eavesdrop on whatever routing protocol messages are being used on
the LAN.
Router Discovery Process
For a summary of the processes that occur when Router Discovery
advertisements are enabled for interfaces on the switch see Table 3 on page 9
Table 3: Router Discovery Process
When ... Then ...
Router Discovery advertising starts on a
switch interface because:
- the switch starts up, or
- advertisements are enabled on the
switch
or on an interface
the switch multicasts a router advertisement
and continues to multicast them periodically
until router advertising is disabled.
a host starts up the host may send a router solicitation
message.