Operating instructions

230 Cisco Systems Intelligent Gigabit Ethernet Switch Module
The most common cause is trying to change the management IP address for the Cisco
Systems IGESM directly on the Cisco Systems IGESM (either through CLI or through CMS).
When a user changes the management VLAN IP address on the Cisco Systems IGESM to
something other than what it received from the Management Module through means other
than the Management Module Web interface, all IP communications to the Cisco Systems
IGESM’s management IP address via the Management Module fail, and the Cisco Systems
IGESM begins to report a duplicate IP address. Note that this duplicate IP address message
happens only if you change it to an address in the same subnet that it was originally on. For
example, changing from 192.168.70.127 to 192.168.70.150 would result in a duplicate IP
address message, while changing from 192.168.70.127 to 10.35.15.1 would not result in a
duplicate IP address message (although it would more than likely result in lost IP
communications to the IGESM through the Management Module).
The following sequence of events demonstrates this issue. (This is for demonstration
purposes only; do not perform this on production systems.)
Show the current IP address of the management VLAN on the Cisco Systems IGESM to
confirm the proper configuration (in this example, we use the default IP address):
CIGESM1#sh run int vlan 1
INTERFACE Vlan1
ip address 192.168.70.127 255.255.255.0
no ip route-cache
Test ping from the Cisco Systems IGESM to the internal IP address of the Management
Module to verify that the connection is working:
CIGESM1#ping 192.168.70.126
Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to 192.168.70.126, timeout is 2 seconds:
!!!!!
Success rate is 100 percent (5/5)
Change the IP address on the Cisco Systems IGESM to another address:
CIGESM1#conf t
Enter configuration commands, one per line. End with CNTL/Z.
CIGESM1(config)#int vlan 1
CIGESM1(config-if)#ip add 192.168.70.150 255.255.255.0
CIGESM1(config-if)#
Shortly after making this change, start receiving duplicate address messages on the console
of the Cisco Systems IGESM:
1d19h: %IP-4-DUPADDR: Duplicate address 192.168.70.150 on Vlan1, sourced by 0009.6bca.7499
Now change back to the original address:
CIGESM1(config-if)#
CIGESM1(config-if)#ip add 192.168.70.127 255.255.255.0
CIGESM1(config-if)#
Continue receiving duplicate address messages:
1d19h: %IP-4-DUPADDR: Duplicate address 192.168.70.127 on Vlan1, sourced by
0009.6bca.7499
Test ping from the Cisco Systems IGESM to the internal IP address of the Management
Module, and it fails:
CIGESM1#ping 192.168.70.126