08-22-2017 08:45 AM - edited 03-08-2019 11:48 AM
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.
08-22-2017 09:03 AM
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 ?
08-22-2017 09:21 AM
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 .
08-22-2017 09:30 AM
08-22-2017 09:38 AM
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.
08-22-2017 09:48 AM
Hello,
odd indeed. Can you post the output of 'show vlan' ?
08-22-2017 09:54 AM
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
08-22-2017 09:54 AM
08-22-2017 10:07 AM
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 ?
08-22-2017 10:13 AM
switches are connected through default vlan and access ports not trunk links.
08-22-2017 10:34 AM
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' ?
08-22-2017 10:36 AM
I have check the switch in standalone mode without connecting to my network but issue is same.
08-22-2017 10:52 AM
Hello,
post the full configuration of the switch, something might be missing...
08-22-2017 11:07 AM
Also, which IOS version are you running ?
Does 'clear arp' resolve the issue ?
08-22-2017 01:59 PM
Hello
Do the hosts have the correct addressing?
Do they have any software fw enabled preventing icmp?
res
Paul
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