5. IP Configuration
• If you are using DHCP to acquire the IP address for the switch, the IP address "lease time" may have expired
so that the IP address has changed. For more information on how to "reserve" an IP address, see the
documentation for the DHCP application that you are using.
• If one or more IP-authorized managers are configured, the switch allows inbound telnet access only to a
device having an authorized IP address. For more information on IP Authorized managers, see the access
security guide for your switch.
Unusual network activity
Network activity that fails to meet accepted norms may indicate a hardware problem with one or more of the
network components, possibly including the switch. Such problems can also be caused by a network loop or
simply too much traffic for the network as it is currently designed and implemented. Unusual network activity is
usually indicated by the LEDs on the front of the switch or measured with the switchconsole interface or with a
network management tool. For information on using LEDs to identify unusual network activity, see the installation
guide you received with the switch.
A topology loop can also cause excessive network activity. The Event Log "FFI" messages can be indicative of
this type of problem.
General problems
The network runs slow; processes fail; users cannot access servers or other devices
Broadcast storms may be occurring in the network. These may be caused by redundant links between nodes.
• If you are configuring a port trunk, finish configuring the ports in the trunk before connecting the related cables.
Otherwise you may inadvertently create a number of redundant links (that is, topology loops) that will cause
broadcast storms.
• Turn on STP to block redundant links
• Check for FFI messages in the Event Log
Duplicate IP addresses
This is indicated by this Event Log message:
ip: Invalid ARP source:
IP address
on
IP address
where both instances of
IP address
are the same address, indicating that the switch's IP address has been
duplicated somewhere on the network.
Duplicate IP addresses in a DHCP network
If you use a DHCP server to assign IP addresses in your network, and you find a device with a valid IP address
that does not appear to communicate properly with the server or other devices, a duplicate IP address may have
been issued by the server. This can occur if a client has not released a DHCP-assigned IP address after the
intended expiration time and the server "leases" the address to another device. This can also happen, For
example, if the server is first configured to issue IP addresses with an unlimited duration, and then is
subsequently configured to issue IP addresses that will expire after a limited duration. One solution is to configure
"reservations" in the DHCP server for specific IP addresses to be assigned to devices having specific MAC
addresses. For more information, see the documentation for the DHCP server.
One indication of a duplicate IP address in a DHCP network is this Event Log message:
ip: Invalid ARP source: <
IP-address
>
on <
IP-address
>
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Aruba 2930F / 2930M Management and Configuration Guide
for ArubaOS-Switch 16.08
