where both instances of
IP-address
are the same address, indicating that the IP address 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.
802.1Q Prioritization problems
Ports configured for non-default prioritization (level 1 to 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.
Addressing ACL problems
ACLs are properly configured and assigned to VLANs, but the switch is not using the
ACLs to filter IP layer 3 packets
Procedure
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:
Indication that routing is enabled
switch(config)# show running
Running configuration:
; J9091A Configuration Editor; Created on release #XX.15.06
hostname "Switch"
ip default-gateway 10.33.248.1
ip routing
1
logging 10.28.227.2
snmp-server community "public" Unrestricted
ip access-list extended "Controls for VLAN 20"
permit tcp 0.0.0.0 255.255.255.255 10.10.20.98 0.0.0.0 eq 80
permit tcp 0.0.0.0 255.255.255.255 10.10.20.21 0.0.0.0 eq 80
deny tcp 0.0.0.0 255.255.255.255 10.10.20.1 0.0.0.255 eq 80
deny tcp 10.10.20.1? 0.0.0.0 10.10.10.100 0.0.0.0 eq 20 log
deny tcp 10.10.20.20 0.0.0.0 10.10.10.100 0.0.0.0 eq 20 log
deny tcp 10.10.20.43 0.0.0.0 10.10.10.100 0.0.0.0 eq 20 log
permit ip 10.10.20.1 0.0.0.255 10.10.10.100 0.0.0.0
deny ip 10.10.30.1 0.0.0.255 10.10.10.100 0.0.0.0
permit ip 10.10.30.1 0.0.0.255 10.10.10.1 0.0.0.255
exit
1
Chapter 13 Troubleshooting
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