HP 2910AL - Manual (Page 497)

Troubleshooting
Unusual Network Activity
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.
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 config­
ured 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.
802.1Q Prioritization Problems
Ports configured for non-default prioritization (level 1 - 7) are not
performing the specified action.
If the ports were placed in a trunk group
after being configured for non-default prioritization, the priority setting was
automatically reset to zero (the default). Ports in a trunk group operate only
at the default priority setting.
ACL Problems
ACLs are properly configured and assigned to VLANs, but the switch
is not using the ACLs to filter IP layer 3 packets.
1. The switch may be running with IP routing disabled. To ensure that IP
routing is enabled, execute show running and look for the IP routing
statement in the resulting listing. For example:
C-9