Troubleshooting

Troubleshooting

Unusual Network Activity

Unusual Network Activity

Network activity that exceeds accepted norms often indicates a hardware problem with one or more of the network components, possibly including the switch. Unusual network activity is usually indicated by the LEDs on the front of the switch or as indicated by measurements from the switch console or from a network management tool such as the HP TopTools for Hubs & Switches. Refer to the installation guide you received with the switch for information on using LEDs to identify unusual network activity.

General ProblemsThe network runs slow; processes fail; users cannot access servers or

other devices. Broadcast storms may be occurring in the network. These may be due to loops in the network topology (redundant links between nodes).

•Inspect your network topology to make sure there are no loops in the network.

•If your network requires redundant links to guarantee maintenance of network connectivity, turn on Spanning Tree Protocol to maintain a single active path and provide for redundant links.

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 the IP address that has been duplicated somewhere on the network.

Duplicate IP Addresses in a DHCP Network. If you use a DHCP server to automatically 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, 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, refer to the documentation for the DHCP server.

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