Fore Systems forerunner series, Руководство по настройке

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ForeRunner ATM Switch Network Configuration Manual
3 - 31
Con
figurin
g an
Em
ul
ated
LAN
Configuring an Emulated LAN
The last two forms of ATM-address matching elements are functionally the same. The latter is
shorter but only allows for masks whose semi-octets are all ones or all zeros, while the former
allows for arbitrary masks. A prospective-client address is “captured” by an ELAN name if
the client’s address matches one of the
Accept
elements but not one of the
Reject
elements
(if present). Finally, an ELAN may be configured to accept any client that wishes to join by
including the following statement:
default.Accept:XX.XXXX.XX.XXXXXX.XXXX.XXXX.XXXX.XXXXXXXXXXXX.XX
The order in which to apply the Accept and Reject rules is given by a
Match.Ordering
group.key statement, whose value is a comma-separated list of ELAN names. For example:
Match.Ordering: default, engineering, marketing
The names of all ELANs that have
Accept
keys must be included in
Match.Ordering
.
The LE_CONFIGURE_REQUEST frame contains an ATM address and an optional MAC
address or route descriptor (which is always present for ELAN access control requests). The
Accept/Reject checking proceeds in two distinct phases: first, for the MAC address or route
descriptor, if present, and second, for the ATM address. So, even though a client might be
rejected by its MAC address, it can be accepted by its ATM address. Therefore, when configur-
ing the Accept and Reject rules, ensure that you write them either as explicit lists of only MAC
addresses or route descriptors, or only as ATM address matches.
3.6.1.4 Defining a Client
Clients need not be defined in the LECS configuration file. Typically, you would define a client
for the purpose of overriding one or more of the default configuration parameters for that par-
ticular client.
A client is defined by using its ATM address, MAC address, or route descriptor in the
group
field, and perhaps giving the name of its ELAN as the value of the
LAN_Name
key. For
example:
47.0005.80.FFE100.0000.0000.0000.002048222222.22.LAN_Name:engineering
002048ABCDEF.LAN_Name: marketing
012F.LAN_Name: publications
Configuration parameter overrides can also be given on a per-client basis. For example, the
following statements override the default
VCC_TimeOut_Period
and
Aging_Time
configu-
ration parameters for a client whose MAC address is
002048080011
on the
engineering
ELAN:
002048080011.LAN_Name:engineering
002048080011.VCC_TimeOut_Period:1200
002048080011.Aging_Time: 30