Trouble ping from same switch, same vlan. Fail origin in Switch?

[Belsismar]

Hi.

I found something unusual when I ping from two hosts connected to the same switch and in the same VLAN.
Host1: 10.10.18.240 Port 37 Switche 2950
Host2: 10.10.18.33 Puerto 38 Switche 2950
Destination: 10.0.128.64

Both host regularly use the published application in that destination. Random error by which to discard network problems occurs.

The basic ping test resulted as follows:

Host1 no pings. (port 37)
Host2 pinging. (port 38)

Swap ports on the Switche and the result was:

Host1 pinging. (port 38)
Host2 no pings. (port 37)

I do not understand what happened. This is the anomaly.
Any ideas?

[Jon Marshall]

Does the port show as up/up ?

Is it in the correct vlan ie. what does "sh vlan brief" show ?

Are there any acls on the ports etc.

What does the configuration look like ?

It could be any number of things.

Jon

[Belsismar]

Hi Jon.

About show:

P9_sw2950_4N#sh vlan br

VLAN Name                             Status    Ports
---- -------------------------------- --------- -------------------------------
1    default                          active    Gi0/1, Gi0/2
10   Corporativa_Piso_1               active
11   Corporativa_Piso_2               active
12   Corporativa_Piso_3               active
13   Corporativa_Piso_4               active
14   Corporativa_Piso_5               active
15   Corporativa_Piso_6               active
16   Corporativa_Piso_13              active
17   Corporativa_Piso_20              active
18   Mezzanina_1                      active    Fa0/4, Fa0/5, Fa0/6, Fa0/10
                                                Fa0/11, Fa0/12, Fa0/13, Fa0/14
                                                Fa0/15, Fa0/16, Fa0/17, Fa0/18
                                                Fa0/19, Fa0/20, Fa0/21, Fa0/23
                                                Fa0/24, Fa0/25, Fa0/26, Fa0/27
                                                Fa0/28, Fa0/29, Fa0/30, Fa0/31
                                                Fa0/32, Fa0/33, Fa0/34, Fa0/35
                                                Fa0/36, Fa0/37, Fa0/38, Fa0/39
                                                Fa0/40, Fa0/41, Fa0/42, Fa0/43
                                                Fa0/44, Fa0/45, Fa0/46, Fa0/48
19   Plata_Baja                       active

P9_sw2950_4N#

No, No ACLs.

P9_sw2950_4N#sh run int fast 0/37
Building configuration...

Current configuration : 61 bytes
!
interface FastEthernet0/37
 switchport access vlan 18
end

P9_sw2950_4N#sh run int fast 0/38
Building configuration...

Current configuration : 61 bytes
!
interface FastEthernet0/38
 switchport access vlan 18
end

P9_sw2950_4N#

[CISCO8006]

check the mac-address table - if there are the correct MAC on the if

may be you mirror the port's and check with wireshark what's going on

try the two port's in an different "dummy" Vlan and try to ping each other (maybe also change the IP's on the Host NIC in a different Subnet for test purposes)