cancel
Showing results for 
Search instead for 
Did you mean: 
cancel
6122
Views
0
Helpful
13
Replies

Fcs errors between two 2960 screw up my network

cbourrier
Level 1
Level 1

Hi,

since two weeks i have my switch1 (2960G 48 port) who get (receive) a lot of FCS errors on the port who is pluged to my another 2960G(who don't  display any fcs error ) and every server who is pluged on my two switchs drop packets , get sql,http,network problem and are very slow...etc

I'am going crazy , i have used many differents cable (shielded cat6) used on many differents ports(on both switchs) , i have trying the follow configuration on my two ports:

switchport trunk allowed vlan 3,101,102,104

switchport mode trunk

switchport trunk allowed vlan 3,101,102,104

switchport mode trunk

switchport nonegotiate

switchport trunk allowed vlan 3,101,102,104

switchport mode trunk

switchport nonegotiate

channel-group 1 mode active (etherchannel in lacp mode both port active , same priority)

switchport trunk allowed vlan 3,101,102,104

switchport mode trunk

switchport nonegotiate

spanning-tree portfast

switchport trunk allowed vlan 3,101,102,104

switchport mode trunk

speed 1000

In this case the port don't work

switchport trunk allowed vlan 3,101,102,104

switchport mode trunk

duplex full

In this case the port don't work

but nothing solve my probleme ,

i have checked controller with show controllers ethernet-controller phy , all are good.

sometime i see the cpu at 80% but when i do show processes cpu sorted all process are at 2% cpu used max....

i have of course restart the switch and i am out of idea.

If you have some that would be nice thanks you.

ps: sorry for my english

13 Replies 13

Reza Sharifi
Hall of Fame
Hall of Fame

Hello Christophe,

Can you post "sh run" from both switches?

Reza

for switch1 (who show error fcs in receive)


Using 6515 out of 65536 bytes
!
version 12.2
no service pad
service timestamps debug datetime msec localtime
service timestamps log datetime msec localtime
service password-encryption
service sequence-numbers
!
hostname Th2-sw1
!
enable secret 5 $1$D1GE$Jcz0cTs5PRfNq8fttlKvh0
!
username AdmCisco password 7 044F0E0A0A2243435B49554E5C
aaa new-model
aaa authentication login default local
!
aaa session-id common
clock timezone UTC 1
clock summer-time UTC recurring last Sun Mar 2:00 last Sun Oct 2:00
system mtu routing 1500
vtp mode transparent
ip subnet-zero
!
ip domain-name budgetelecom.com
!
!
!
no file verify auto
!
spanning-tree mode pvst
spanning-tree extend system-id
spanning-tree vlan 1-1000 priority 45056
!
vlan internal allocation policy ascending
!
vlan 3
name rouge
!
vlan 101
name bleu
!
vlan 102
name vert
!
vlan 103
!
vlan 104
name rose
!
interface Port-channel1
!
interface GigabitEthernet0/1
switchport trunk allowed vlan 102
switchport mode trunk
switchport nonegotiate
!
interface GigabitEthernet0/2
switchport trunk allowed vlan 3,101
switchport mode trunk
switchport nonegotiate
!
interface GigabitEthernet0/3
switchport trunk allowed vlan 3,101,102,104
switchport mode trunk
switchport nonegotiate
spanning-tree portfast
!
interface GigabitEthernet0/4
switchport access vlan 102
switchport mode access
spanning-tree portfast
!
interface GigabitEthernet0/5
switchport access vlan 102
switchport mode access
spanning-tree portfast
!
interface GigabitEthernet0/6
switchport access vlan 102
switchport mode access
spanning-tree portfast
!
interface GigabitEthernet0/7
switchport access vlan 102
switchport mode access
spanning-tree portfast
!
interface GigabitEthernet0/8
switchport access vlan 102
switchport mode access
spanning-tree portfast
!
interface GigabitEthernet0/9
switchport access vlan 102
switchport mode access
spanning-tree portfast
!
interface GigabitEthernet0/10
switchport access vlan 102
switchport mode access
spanning-tree portfast
!
interface GigabitEthernet0/11
switchport access vlan 102
switchport mode access
spanning-tree portfast
!
interface GigabitEthernet0/12
switchport access vlan 102
switchport mode access
spanning-tree portfast
!
interface GigabitEthernet0/13
switchport access vlan 102
switchport mode access
spanning-tree portfast
!
interface GigabitEthernet0/14
switchport access vlan 102
switchport mode access
spanning-tree portfast
!
interface GigabitEthernet0/15
switchport access vlan 102
switchport mode access
spanning-tree portfast
!
interface GigabitEthernet0/16
switchport access vlan 102
switchport mode access
spanning-tree portfast
!
interface GigabitEthernet0/17
switchport access vlan 3
switchport mode access
spanning-tree portfast
!
interface GigabitEthernet0/18
switchport access vlan 3
switchport mode access
spanning-tree portfast
!
interface GigabitEthernet0/19
switchport access vlan 3
switchport mode access
spanning-tree portfast
!
interface GigabitEthernet0/20
switchport access vlan 3
switchport mode access
spanning-tree portfast
!
interface GigabitEthernet0/21
switchport access vlan 3
switchport mode access
spanning-tree portfast
!
interface GigabitEthernet0/22
switchport access vlan 3
switchport mode access
spanning-tree portfast
!
interface GigabitEthernet0/23
switchport access vlan 3
switchport mode access
spanning-tree portfast
!
interface GigabitEthernet0/24
switchport access vlan 3
switchport mode access
spanning-tree portfast
!
interface GigabitEthernet0/25
switchport trunk allowed vlan 3,101,102,104
switchport mode trunk
switchport nonegotiate
!
interface GigabitEthernet0/26
switchport access vlan 101
switchport mode access
spanning-tree portfast
!
interface GigabitEthernet0/27
switchport access vlan 101
switchport mode access
load-interval 30
spanning-tree portfast
!
interface GigabitEthernet0/28
switchport access vlan 101
switchport mode access
spanning-tree portfast
!
interface GigabitEthernet0/29
switchport access vlan 104
switchport mode access
spanning-tree portfast
!
interface GigabitEthernet0/30
switchport access vlan 104
switchport mode access
spanning-tree portfast
!
interface GigabitEthernet0/31
switchport access vlan 104
switchport mode access
spanning-tree portfast
!
interface GigabitEthernet0/32
switchport access vlan 104
switchport mode access
spanning-tree portfast
!
interface GigabitEthernet0/33
switchport access vlan 104
switchport mode access
!
interface GigabitEthernet0/34
switchport access vlan 104
switchport mode access
spanning-tree portfast
!
interface GigabitEthernet0/35
switchport access vlan 104
switchport mode access
spanning-tree portfast
!
interface GigabitEthernet0/36
switchport trunk allowed vlan 3,101,102,104
switchport mode trunk
switchport nonegotiate
spanning-tree portfast
!
interface GigabitEthernet0/37
switchport access vlan 102
switchport mode access
spanning-tree portfast
!
interface GigabitEthernet0/38
switchport trunk allowed vlan 3,101,102,104
switchport mode trunk
switchport nonegotiate
!
interface GigabitEthernet0/39
switchport trunk allowed vlan 3,101,102,104
switchport mode trunk
switchport nonegotiate
spanning-tree portfast
!
interface GigabitEthernet0/40
switchport trunk allowed vlan 3,101,102,104
switchport mode trunk
duplex full
!
interface GigabitEthernet0/41
switchport trunk allowed vlan 3,101,102,104
switchport mode trunk
speed 1000
!
interface GigabitEthernet0/42
!
interface GigabitEthernet0/43
!
interface GigabitEthernet0/44
!
interface GigabitEthernet0/45
switchport trunk allowed vlan 3,101,102,104
switchport mode trunk
switchport nonegotiate
channel-group 1 mode active
!
interface GigabitEthernet0/46
switchport trunk allowed vlan 3,101,102,104
switchport mode trunk
switchport nonegotiate
channel-group 1 mode active
!
interface GigabitEthernet0/47
switchport trunk allowed vlan 3,101,102,104
switchport mode trunk
switchport nonegotiate
!
interface GigabitEthernet0/48
switchport trunk allowed vlan 3,101,102,104
switchport mode trunk
!
interface Vlan1
no ip address
no ip route-cache
!
interface Vlan102
ip address 10.2.2.247 255.255.255.0
no ip route-cache
!
ip default-gateway 10.2.2.250
ip http server
no cdp run
snmp-server community th2-sw1 RO
snmp-server location TH2
snmp-server contact julien vincent
radius-server source-ports 1645-1646
!
control-plane
!
!
line con 0
line vty 0 4
password 7 03105E07030C2E411C59495C59
line vty 5 15
password 7 03105E07030C2E411C59495C59
!
end

Th2-sw1#             

for my second switch (who don't display any error)

show conf
Using 6592 out of 65536 bytes
!
version 12.2
no service pad
service timestamps debug datetime msec localtime
service timestamps log datetime msec localtime
service password-encryption
!
hostname Th2-sw2
!
enable secret 5 $1$D1GE$Jcz0cTs5PRfNq8fttlKvh0
!
username AdmCisco password 7 044F0E0A0A2243435B49554E5C
aaa new-model
aaa authentication login default local
!
aaa session-id common
clock timezone UTC 1
clock summer-time UTC recurring last Sun Mar 2:00 last Sun Oct 2:00
system mtu routing 1500
vtp mode transparent
ip subnet-zero
!
ip domain-name budgetelecom.com
!
!
!
no file verify auto
!
spanning-tree mode pvst
spanning-tree extend system-id
spanning-tree vlan 1-1000 priority 49152
!
vlan internal allocation policy ascending
!
vlan 3
name rouge
!
vlan 100
!
vlan 101
name bleu
!
vlan 102
name vert
!
vlan 104
name rose
!
interface Port-channel1
!
interface GigabitEthernet0/1
switchport trunk allowed vlan 102
switchport mode trunk
switchport nonegotiate
!
interface GigabitEthernet0/2
switchport trunk allowed vlan 3,101
switchport mode trunk
switchport nonegotiate
!
interface GigabitEthernet0/3
switchport trunk allowed vlan 3,101,102,104
switchport mode trunk
switchport nonegotiate
spanning-tree portfast
!
interface GigabitEthernet0/4
switchport access vlan 102
switchport mode access
spanning-tree portfast
!
interface GigabitEthernet0/5
switchport access vlan 102
switchport mode access
spanning-tree portfast
!
interface GigabitEthernet0/6
switchport access vlan 102
switchport mode access
spanning-tree portfast
!
interface GigabitEthernet0/7
switchport access vlan 102
switchport mode access
spanning-tree portfast
!
interface GigabitEthernet0/8
switchport access vlan 102
switchport mode access
spanning-tree portfast
!
interface GigabitEthernet0/9
switchport access vlan 102
switchport mode access
spanning-tree portfast
!
interface GigabitEthernet0/10
switchport access vlan 102
switchport mode access
spanning-tree portfast
!
interface GigabitEthernet0/11
switchport access vlan 102
switchport mode access
shutdown
spanning-tree bpdufilter enable
!
interface GigabitEthernet0/12
switchport access vlan 102
switchport mode access
spanning-tree portfast
!
interface GigabitEthernet0/13
switchport access vlan 102
switchport mode access
spanning-tree portfast
!
interface GigabitEthernet0/14
switchport access vlan 102
switchport mode access
spanning-tree portfast
!
interface GigabitEthernet0/15
switchport access vlan 102
switchport mode access
spanning-tree portfast
!
interface GigabitEthernet0/16
switchport access vlan 102
switchport mode access
spanning-tree portfast
!
interface GigabitEthernet0/17
switchport access vlan 3
switchport mode access
spanning-tree portfast
!
interface GigabitEthernet0/18
switchport access vlan 3
switchport mode access
spanning-tree portfast
!
interface GigabitEthernet0/19
switchport access vlan 3
switchport mode access
spanning-tree portfast
!
interface GigabitEthernet0/20
switchport access vlan 3
switchport mode access
spanning-tree portfast
!
interface GigabitEthernet0/21
switchport access vlan 3
switchport mode access
spanning-tree portfast
!
interface GigabitEthernet0/22
switchport access vlan 3
switchport mode access
spanning-tree portfast
!
interface GigabitEthernet0/23
switchport access vlan 3
switchport mode access
spanning-tree portfast
!
interface GigabitEthernet0/24
switchport access vlan 3
switchport mode access
spanning-tree portfast
!
interface GigabitEthernet0/25
switchport access vlan 101
switchport mode access
spanning-tree portfast
!
interface GigabitEthernet0/26
switchport access vlan 101
switchport mode access
spanning-tree portfast
!
interface GigabitEthernet0/27
switchport access vlan 101
switchport mode access
load-interval 30
spanning-tree portfast
!
interface GigabitEthernet0/28
switchport access vlan 101
switchport mode access
spanning-tree portfast
!
interface GigabitEthernet0/29
switchport access vlan 104
switchport mode access
spanning-tree portfast
!
interface GigabitEthernet0/30
switchport access vlan 104
switchport mode access
spanning-tree portfast
!
interface GigabitEthernet0/31
switchport access vlan 104
switchport mode access
spanning-tree portfast
!
interface GigabitEthernet0/32
switchport access vlan 104
switchport mode access
spanning-tree portfast
!
interface GigabitEthernet0/33
switchport access vlan 104
switchport mode access
spanning-tree portfast
!
interface GigabitEthernet0/34
switchport access vlan 104
switchport mode access
spanning-tree portfast
!
interface GigabitEthernet0/35
switchport access vlan 104
switchport mode access
spanning-tree portfast
!
interface GigabitEthernet0/36
switchport trunk allowed vlan 3,101,102,104
switchport mode trunk
switchport nonegotiate
spanning-tree portfast
!
interface GigabitEthernet0/37
switchport access vlan 102
switchport mode access
spanning-tree portfast
!
interface GigabitEthernet0/38
switchport trunk allowed vlan 3,101,102,104
switchport mode trunk
switchport nonegotiate
!
interface GigabitEthernet0/39
switchport trunk allowed vlan 3,101,102,104
switchport mode trunk
switchport nonegotiate
spanning-tree portfast
!
interface GigabitEthernet0/40
switchport trunk allowed vlan 3,101,102,104
switchport mode trunk
duplex full
!
interface GigabitEthernet0/41
switchport trunk allowed vlan 3,101,102,104
switchport mode trunk
speed 1000
!
interface GigabitEthernet0/42
switchport access vlan 100
switchport mode access
!
interface GigabitEthernet0/43
switchport access vlan 100
switchport mode access
switchport nonegotiate
speed 100
!
interface GigabitEthernet0/44
switchport access vlan 100
switchport mode access
!
interface GigabitEthernet0/45
switchport trunk allowed vlan 3,101,102,104
switchport mode trunk
switchport nonegotiate
channel-group 1 mode active
!
interface GigabitEthernet0/46
switchport trunk allowed vlan 3,101,102,104
switchport mode trunk
switchport nonegotiate
channel-group 1 mode active
!
interface GigabitEthernet0/47
switchport mode trunk
switchport nonegotiate
shutdown
!
interface GigabitEthernet0/48
switchport trunk allowed vlan 3,101,102,104
switchport mode trunk
!
interface Vlan1
no ip address
no ip route-cache
shutdown
!
interface Vlan102
ip address 10.2.2.248 255.255.255.0
no ip route-cache
!
ip default-gateway 10.2.2.250
ip http server
no cdp run
snmp-server community th2-sw2 RO
snmp-server location TH2
snmp-server contact julien vincent
radius-server source-ports 1645-1646
!
control-plane
!
!
line con 0
line vty 5 15
!
end

Th2-sw2#     

Hello,

FCS (Frame Check Sequence) is calculated on frames received/sent over ethernet to check for frame's correctness.

I understand that in your network you are experiencing packet drops and latency. First of all FCS errors are caused due to layer two issues mostly mismatch of duplex on both ends of links. Say, you have this end of link running at 100 FULL but other end is wokring at 100 HALF, then it will cause some serious drops/slowness etc.


.I have included a link below to help you troubleshoot ethernet issues :

http://www.cisco.com/en/US/tech/tk389/tk214/technologies_tech_note09186a0080094781.shtml

Again, coming back to your issue of slowness, you need to have a look at the detailed topology diagram, and do pings from one point of n/w to other end, and keep a note of RTT and go on measuring latency, until you come up with the bottleneck device.

Latency issues generally require lot fo detailed troubleshooting, whihc maybe out of scope of discussion forums. Try to open a TAC case with Cisco.

HTH

Vijaya

i don't understand vijaya when you say  ", you have this end of link running at 100 FULL but other end is wokring at 100 HALF"

all server and switch are in full duplex .

Btw a things very strange happended when i force the full duplex mode or speed 1000 on port between my two switch , the ports are down, they didn't lighting , but in nonegotiate mode i 'am in full duplex /1000 and it's work...

Leo Laohoo
Hall of Fame
Hall of Fame

May I request if you post the output for "sh controll ether " of both uplinks?

     Transmit GigabitEthernet0/46             Receive
   2180367708 Bytes                       3940032344 Bytes                   
     47689370 Unicast frames                26142784 Unicast frames          
          296 Multicast frames                450702 Multicast frames        
        28338 Broadcast frames                 10408 Broadcast frames        
            0 Too old frames              3721317512 Unicast bytes           
            0 Deferred frames              109857300 Multicast bytes         
            0 MTU exceeded frames             742638 Broadcast bytes         
            0 1 collision frames                   0 Alignment errors        
            0 2 collision frames                6430 FCS errors              
            0 3 collision frames                   0 Oversize frames         
            0 4 collision frames                   0 Undersize frames        
            0 5 collision frames                   0 Collision fragments     
            0 6 collision frames      
            0 7 collision frames             1343003 Minimum size frames     
            0 8 collision frames            14032299 65 to 127 byte frames   
            0 9 collision frames            10961750 128 to 255 byte frames  
            0 10 collision frames              73759 256 to 511 byte frames  
            0 11 collision frames              85283 512 to 1023 byte frames 
            0 12 collision frames             114082 1024 to 1518 byte frames
            0 13 collision frames                  0 Overrun frames          
            0 14 collision frames                  0 Pause frames            

            0 15 collision frames     
            0 Excessive collisions                 0 Symbol error frames     
            0 Late collisions                    147 Invalid frames, too large
            0 VLAN discard frames                  0 Valid frames, too large 
            0 Excess defer frames                  0 Invalid frames, too small
       277014 64 byte frames                       0 Valid frames, too small 
     34717043 127 byte frames         
     12051460 255 byte frames                      0 Too old frames          
       199447 511 byte frames                      0 Valid oversize frames   
       171916 1023 byte frames                     0 System FCS error frames 
       301124 1518 byte frames                     0 RxPortFifoFull drop frame
            0 Too large frames        
            0 Good (1 coll) frames    
            0 Good (>1 coll) frames 

     Transmit GigabitEthernet0/45             Receive
    545502922 Bytes                       2020889009 Bytes                   
      1850392 Unicast frames                18063342 Unicast frames          
        25102 Multicast frames                 32865 Multicast frames        
        12931 Broadcast frames                 17497 Broadcast frames        
            0 Too old frames              1921081200 Unicast bytes           
            0 Deferred frames               25785242 Multicast bytes         
            0 MTU exceeded frames            1240783 Broadcast bytes         
            0 1 collision frames                   0 Alignment errors        
            0 2 collision frames                1091 FCS errors              
            0 3 collision frames                   0 Oversize frames         
            0 4 collision frames                   0 Undersize frames        
            0 5 collision frames                   0 Collision fragments     
            0 6 collision frames      
            0 7 collision frames              945594 Minimum size frames     
            0 8 collision frames            14812695 65 to 127 byte frames   
            0 9 collision frames             1836665 128 to 255 byte frames  
            0 10 collision frames             109579 256 to 511 byte frames  
            0 11 collision frames             375904 512 to 1023 byte frames 
            0 12 collision frames              34349 1024 to 1518 byte frames
            0 13 collision frames                  0 Overrun frames          
            0 14 collision frames                  0 Pause frames             
            0 15 collision frames     
            0 Excessive collisions                 0 Symbol error frames     
            0 Late collisions                      9 Invalid frames, too large
            0 VLAN discard frames                  0 Valid frames, too large 
            0 Excess defer frames                  0 Invalid frames, too small
       131735 64 byte frames                       0 Valid frames, too small 
       304587 127 byte frames         
      1263597 255 byte frames                      0 Too old frames          
        30046 511 byte frames                      0 Valid oversize frames   
        20675 1023 byte frames                     0 System FCS error frames 
       137785 1518 byte frames                     0 RxPortFifoFull drop frame
            0 Too large frames        
            0 Good (1 coll) frames    
            0 Good (>1 coll) frames 

Th2-sw1#

for the switch who get error

and for the second i have

     Transmit GigabitEthernet0/46             Receive
   3259224661 Bytes                       2129159225 Bytes                   
    677223805 Unicast frames              1262545270 Unicast frames          
     11225778 Multicast frames                 93558 Multicast frames        
       472958 Broadcast frames               1294370 Broadcast frames        
            0 Too old frames              1265926740 Unicast bytes           
            0 Deferred frames                7930105 Multicast bytes         
            0 MTU exceeded frames           94591776 Broadcast bytes         
            0 1 collision frames                   0 Alignment errors        
            0 2 collision frames                   0 FCS errors              
            0 3 collision frames                   0 Oversize frames         
            0 4 collision frames                   0 Undersize frames        
            0 5 collision frames                   0 Collision fragments     
            0 6 collision frames      
            0 7 collision frames             5153758 Minimum size frames     
            0 8 collision frames           881994930 65 to 127 byte frames   
            0 9 collision frames           245097460 128 to 255 byte frames  
            0 10 collision frames            2975451 256 to 511 byte frames  
            0 11 collision frames            3304493 512 to 1023 byte frames 
            0 12 collision frames          125407108 1024 to 1518 byte frames
            0 13 collision frames                  0 Overrun frames          
            0 14 collision frames                  0 Pause frames            
            0 15 collision frames     
            0 Excessive collisions                 0 Symbol error frames     
            0 Late collisions                      0 Invalid frames, too large
            0 VLAN discard frames                  0 Valid frames, too large 
            0 Excess defer frames                  0 Invalid frames, too small
     72944368 64 byte frames                       0 Valid frames, too small 
    375706316 127 byte frames         
    226725474 255 byte frames                      0 Too old frames          
      2291995 511 byte frames                      0 Valid oversize frames   
      2406526 1023 byte frames                147249 System FCS error frames 
      8995111 1518 byte frames                     0 RxPortFifoFull drop frame
            0 Too large frames        
            0 Good (1 coll) frames    
            0 Good (>1 coll) frames 

     Transmit GigabitEthernet0/45             Receive
   3641953495 Bytes                       1738593180 Bytes                   
    451916607 Unicast frames                41939995 Unicast frames          
      1162444 Multicast frames               1401042 Multicast frames        
       765887 Broadcast frames                593499 Broadcast frames        
            0 Too old frames               394510278 Unicast bytes           
            0 Deferred frames             1120983217 Multicast bytes         
            0 MTU exceeded frames           47415981 Broadcast bytes         
            0 1 collision frames                   0 Alignment errors        
            0 2 collision frames                   0 FCS errors              
            0 3 collision frames                   0 Oversize frames         
            0 4 collision frames                   0 Undersize frames        
            0 5 collision frames                   0 Collision fragments     
            0 6 collision frames      
            0 7 collision frames             6871026 Minimum size frames     
            0 8 collision frames             9769443 65 to 127 byte frames   
            0 9 collision frames            13195624 128 to 255 byte frames  
            0 10 collision frames            1141116 256 to 511 byte frames  
            0 11 collision frames             756668 512 to 1023 byte frames 
            0 12 collision frames           12200659 1024 to 1518 byte frames
            0 13 collision frames                  0 Overrun frames          
            0 14 collision frames                  0 Pause frames            

            0 15 collision frames     
            0 Excessive collisions                 0 Symbol error frames     
            0 Late collisions                      0 Invalid frames, too large
            0 VLAN discard frames                  0 Valid frames, too large 
            0 Excess defer frames                  0 Invalid frames, too small
     19677205 64 byte frames                       0 Valid frames, too small 
    388530969 127 byte frames         
     27924970 255 byte frames                      0 Too old frames          
      1690667 511 byte frames                      0 Valid oversize frames   
     15027983 1023 byte frames                 21087 System FCS error frames 
      1014231 1518 byte frames                     0 RxPortFifoFull drop frame
            0 Too large frames        
            0 Good (1 coll) frames    
            0 Good (>1 coll) frames 

Th2-sw2#

    You can't hardcode the speeds because mdix-auto is on for your ports . if you want to try and hardcode the ports then on the ports enter "no mdix-auto".  Ports will only work in auto  when this is turned on .

if you look the conf you will see i have  forced the speed and fullduplex on port 40 and 41 (no mdix)

GigabiEthernet0/45 and 46 has high FCS errors.  Since FCS are normally found in the "receive" side, look at the switch with no errors and concentrate there.  Try moving to a different ports.

Worst case scenario:  Try using the 2960's Time Domain Reflectometer (TDR) to test the cabling.

http://www.cisco.com/en/US/docs/switches/lan/catalyst4500/12.2/50sg/command/reference/snmp_vtp.html#wp1208382

Warning:  TDR testing is disruptive.

Maybe i have forgoten to say that but i have tested the connection between my switchs on seven differents port and method (3--3,38---38,40--40,41--41,47--47,48--48 and actually 45-46--45-46) i have already tested (test cable-diagnostics tdr interface gigabitEthernet 0/X) and change the cabling six times .

I following your advice and after looking on switch who have no probleme(his name is th2-swi2) i see an another switch (dell powerconnect 3424 , his name is gbswi04)  recieve error on the port who is pluged on th2-swi2(the switch who don't show error) , i see on my th2-swi2 btw a lot of undersize packet incomming from my firewall (asa 5510) do you think that can be generate fcs error on th1-swi1 (the switch who receive error) even if is not directly pluged on my firewall?

A switch will not pass through FCS (or any other) error frames. Undersize packets will be dropped by the switch.

Pete

look like it's th2-swi2 the switch who didn't display any error who is the problem...

But how i can monitor that? (all controller /process/packets/cable/ports are looking good,already try to change the ports and the conf)

Getting Started

Find answers to your questions by entering keywords or phrases in the Search bar above. New here? Use these resources to familiarize yourself with the community:

Innovations in Cisco Full Stack Observability - A new webinar from Cisco