Fault symptom
I have participated in a cabling project where one CISCO 4006 trunk switch is used as a route between VLANs. In addition, there are more than 10 C1SCO 2924 desktop switches and one CISCO 3640 egress router.
The CISCO works 4.0 LAN Solution software suite (LMS 2000) is installed on a Windows NT 2.0 + IE5.5 computer ), however, when you view the network Topology in the Campus Manager Topology Serverices Layer2view, you can only see one CISCO 2924 switch, a CISCO 4006 switch, and a CISCO 3640 router, but not any other CISCO 2924 switches.
Diagnosis Process
First, check the connectivity. The author checks whether the network management computer can Ping these "stealth" switches. Secondly, checks the SNMP settings to see if the Community tring settings of each device are the same. Finally, confirm the connection through cdp: Can other neighbors be seen on each switch? The above tests are successful, indicating that the settings are correct. The following is the configuration of a 2924 switch:
[Omitted...]
!
Hostname Switch
!
Enable secret 5 $1 $ OIKdsftJSJdKKUfLoNkhUJN; L
!
Ip subnet-zero
!
Interface FastEthernet0/1
Switchport access vlan 2
[Omitted...]
!
Interface FastEthernet0/24
Switchport trunk encapsulation dotlq
Switchport mode trunk
!
Interface VLAN1
Ip address 10.1.1.1 255.255.255.0
No ip directed-broadcast
No ip route-cache
!
Snmp-server enginelD local 0000039384830075035 BFCO
Snmp-server community xxxx RO
Snmp-server community yyyy RW
[Omitted...] |
I suspected the compatibility between the LMS software and WindowsNT, and re-installed the Operating System. This time I used Windows2000 + IE6 · 0, and the problem persists.
The strange thing is that vswitches that cannot be seen in the network topology can be managed using Telnet or other methods; the "Cross vro border" option in Discovery Setting is selected (If this option is not selected, no devices outside the network segment of the network management workstation are found). The SE configuration of the 4006 switch is also correct.
[4006 configuration Summary]
#snmp
set snmp community read-only xxxx
set snmp community read-write yyyy
set snmp community read-write-all yyyy
#vtp
set vtp domain xxxx
set vlan 1 name default type ethernet mtu 1500 said 100001 state
active
set vlan 1
!
#iP
set interface scO 1 10.1.1.21/255.255.255.0 10.1.1.255
set ip route 0.0.0.0/0.0.0.0 10.1.1.254
#module 2 : 34-port Router Switch Card
set trunk 2/1 on dotlq 1-1005
!
#module 3 , 24-port 100BaseFX Ethernet
set trunk 3/1 on dotlq 1-1005 |
I have also observed that if I delete The devices shown in the topology and perform the Discovery operation again, I can only find one of the 2924 switches, which is not necessarily the one that I can find.
Therefore, the author's suspicion is to focus on the configuration of the 2924 switch and check whether the number on each computer is the same: snmp-server enginelD local 0000039384830075035 BFCO. In addition, the author also checks the configuration of three 2924 vswitches and the output of "show cdp nei Detal" on the 4006 vro. By comparing the configurations of the three 2924 switches, I found that snmp-server enginelD is different from each other, but the default "Switch" is used for the host names, which can be seen from the output of show cdp nei detail. After a different name is set for these vswitches, the topology is displayed normally.
Tips
In this example, the management software LMS 2.0 is much improved compared with previous versions, one of which can display the Host name (System name ), in the past, only the IP address of the device was displayed, but such a Bug did not occur. Therefore, when using this type of software, you must pay attention to the differences between the new and old versions, so that you can avoid the problem.
