Novell NETWARE 6, Руководство пользователя

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138
Internetwork Packet Exchange
Internetwork Packet Exchange
103-000176-001
August 29, 2001
Novell Confidential
Manual 99a
38
July 17, 2001
Multiple Systems on a LAN Become Unreachable Intermittently
If multiple systems on a LAN become unreachable intermittently, the
Designated Router might be the source of the problem.
Cause 1 —Designated Router does not have enough system memory to
represent the LAN.
To determine whether this is the case, you can check whether the Designated
Router is overloaded when the problem occurs or whether it has been
overloaded in the past. Check the Level 1 Data Base Overloads statistic in
IPXCON (parameter path: Select NLSP Information > System Information >
Detailed NLSP System Information). If the Designated Router does not have
sufficient memory to represent the LAN, then the LAN loses connectivity as
new systems are added. You must then select another system on the network
to become the Designated Router by increasing its priority in NIASCFG and
issuing the REINITIALIZE SYSTEM command. In addition, you must add
memory to the system that was overloaded. You might also want to check
whether other systems in the network are overloaded. Refer to
“Many Systems
Are Entering an Overloaded State.”
Cause 2 —Designated Router or some other system on the LAN is causing the
network outage. Another system can cause this problem by electing itself as
the Designated Router on the LAN.
A single malfunctioning system on a LAN might be causing all systems on the
LAN to become unreachable intermittently. Using IPXCON, check the
Designated Router Changes counter for all systems on the LAN (parameter
path: Select Circuits > a specific circuit > Detailed Circuit Information). If a
single system has a large value displayed in the Designated Router Changes
counter, the system probably has connectivity problems with other systems on
the LAN. Check whether the counter increases over time. If the Designated
Router is not being restarted or unbound from a LAN, the counter should not
increase. If the Designated Router Changes counters of all systems on the
LAN are increasing, the system that should be the Designated Router probably
has a connectivity problem. To determine whether the problem is particular to
the system or to the network itself, remove the system from the LAN or
decrease its Designated Router priority.
Cause 3 —Two systems are contending to be the Designated Router for the
LAN.
In this case, the Own LSP Purges counter increases (parameter path: Select
NLSP Information > System Information > Detailed NLSP System