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

Belsismar · ‎10-20-2015

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 · ‎10-20-2015

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 · ‎10-21-2015

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 · ‎10-26-2015

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)