unable to communicate through cisco 2960 switch

[bijay.swain]

Hi
One cisco 2960 24 port switch is connected in our network . Hosts connected to this switch are able to ping/communicate to switch vlan 1 ip address. but hosts are not able to ping/communicate with each other .
Switch has only one vlan that is default vlan. all hosts and switch are in one subnet .
Switch is able to receive CDP messages from other connected switches but no hosts are able to communicate to the hosts connected to this switch.
I upgraded to new IOS .deleted vlan.dat and config.text file and recreated it but issue remains.

when the switch was working fine there were some memory error showing in console messages but once rebooted there is no error but this issue started.

[Georg Pauwen]

Hello,

are hosts connected to the SAME switch not able to communicate ? Layer 3 (VLAN 1 IP address) would not even be relevant. Can you post the config of the switch ?

Do all hosts have valid IP addresses from the same subnet ?

[bijay.swain]

even if my hosts are connected to same switch one to port 1 and other to port 2 hosts are not able to ping. all are in same subnet.

host1 connected to port 1 having ip 192.168.1.2/24 -vlan1

host2 connected to port 2 having ip 192.168.1.3/24 -vlan1

switch vlan 1 ip 192.168.1.1/24 

both host able to ping and telnet to switch ip (192.168.1.1) but not able to ping each other . and I confirm that there is no host firewall issue .

[rasmus.elmholt]

Hi

Is the switch able to ping the 2 computers back?
This could rule the host firewall out 100%

[bijay.swain]

yes switch is able to ping hosts. and hosts are able to telnet to switch also. but communication between hosts are not happening. can it be due to any hardware issue in switch . or IOS/config issue.

[Georg Pauwen]

Hello,

odd indeed. Can you post the output of 'show vlan' ?

[bijay.swain]

Switch#sh vlan

VLAN Name Status Ports
---- -------------------------------- --------- -------------------------------
1 default active Fa0/1, Fa0/2, Fa0/3, Fa0/4
Fa0/5, Fa0/6, Fa0/7, Fa0/8
Fa0/9, Fa0/10, Fa0/11, Fa0/12
Fa0/13, Fa0/14, Fa0/15, Fa0/16
Fa0/17, Fa0/18, Fa0/19, Fa0/20
Fa0/21, Fa0/22, Fa0/23, Fa0/24
Gi0/1, Gi0/2
2 VLAN0002 active
1002 fddi-default act/unsup
1003 token-ring-default act/unsup
1004 fddinet-default act/unsup
1005 trnet-default act/unsup

VLAN Type SAID MTU Parent RingNo BridgeNo Stp BrdgMode Trans1 Trans2
---- ----- ---------- ----- ------ ------ -------- ---- -------- ------ ------
1 enet 100001 1500 - - - - - 0 0
2 enet 100002 1500 - - - - - 0 0
1002 fddi 101002 1500 - - - - - 0 0
1003 tr 101003 1500 - - - - - 0 0
1004 fdnet 101004 1500 - - - ieee - 0 0
1005 trnet 101005 1500 - - - ibm - 0 0

CHeck attached file for more info

[rasmus.elmholt]

I have only seen this on the ME line of switches if the port was configured for end customers.
Could you share the show mac address-table & show ip arp from the switch.

[Georg Pauwen]

Hello,

post the configuration of the switch, as well as the output of 'show vtp status'.

What happens if you shut the trunks connecting the switch to the other switches ?

[bijay.swain]

switches are connected through default vlan and access ports not trunk links.

[Georg Pauwen]

Hello,

in the attached log file, there are messages about VTP mismatches. I want to find out of that affects the switch. Disconnect all other switches (or shut down the links to those switches), and check if the host on the then standalone switch can communicate.

What is the output of 'show vtp status' ?

[bijay.swain]

I have check the switch in standalone mode without connecting to my network but issue is same.

[Georg Pauwen]

Hello,

post the full configuration of the switch, something might be missing...

[Georg Pauwen]

Also, which IOS version are you running ?

Does 'clear arp' resolve the issue ?

[paul driver]

Hello

Do the hosts have the correct addressing?
Do they have any software fw enabled preventing icmp?

res
Paul