Troubleshooting

Unusual Network Activity

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.

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

where: both instances of IP address are the same address, indicating the IP address that has been duplicated somewhere on the network.

The Switch Has Been Configured for DHCP/Bootp Operation, But Has

Not Received a DHCP or Bootp Reply. When the switch is first configured for DHCP/Bootp operation, or if it is rebooted with this configuration, it immediately begins sending request packets on the network. If the switch does not receive a reply to its DHCP/Bootp requests, it continues to periodically send request packets, but with decreasing frequency. Thus, if a DHCP or Bootp server is not available or accessible to the switch when DHCP/Bootp is first configured, the switch may not immediately receive the desired configuration. After verifying that the server has become accessible to the switch, reboot the switch to re-start the process.

IGMP-Related Problems

IP Multicast (IGMP) Traffic That Is Directed By IGMP Does Not Reach IGMP Hosts or a Multicast Router Connected to a Port. IGMP must

be enabled on the switch and the affected port must be configured for “Auto” or “Forward” operation.

IP Multicast Traffic Floods Out All Ports; IGMP Does Not Appear To

Filter Traffic. The IGMP feature does not operate if the switch or VLAN does not have an IP address configured manually or obtained through DHCP/Bootp. To verify whether an IP address is configured for the switch or VLAN, do either of the following:

■Try Using the Web Browser Interface: If you can access the web browser interface, then an IP address is configured.

■Try To Telnet to the Switch Console: If you can Telnet to the switch, then an IP address is configured.

■Using the Switch Console Interface: From the Main Menu, check the Management Address Information screen by clicking on

1.Status and Counters

2.Switch Management Address Information

Troubleshooting

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