Challenges with SPAN

[kenkisare]

Hi All,

I am facing a challenge with SPAN whenever i change speed to 1000mbps on my  destination port , my interface status goes to down/down on my destination port (g1/0/23) but if i set it to 100mbps it works fine.i need to fix 1000 mbps, what do i need to do?

Note device attached to port g1/0/23 supports 1000 Mbps

these are my current settings

SwitchA#show monitor session 1
Session 1
---------
Type                   : Local Session
Source Ports           :
    Both               : Gi1/0/13,Gi1/0/21-22
Destination Ports      : Gi1/0/23
    Encapsulation      : Native
          Ingress : Disabled

SwitchA#

SwitchA#

SwitchA#show run int g1/0/23
Building configuration...

Current configuration : 89 bytes
!
interface GigabitEthernet1/0/23
  speed 100
end

SwitchA#show int g1/0/23 status

Port      Name               Status       Vlan       Duplex  Speed Type
Gi1/0/23   -                   monitoring   1          a-full    100 10/100/1000BaseTX
SwitchA#
SwitchA#show ip int g1/0/23   
GigabitEthernet1/0/23 is up, line protocol is down
  Inbound  access list is not set
SwitchA#show ip int brief g1/0/23
Interface              IP-Address      OK? Method Status                Protocol
GigabitEthernet1/0/23  unassigned      YES unset  up                    down   
SwitchA#

but if i fix speed 1000

i end up with

SwitchA#show ip int brief g1/0/23
Interface              IP-Address      OK? Method Status                Protocol
GigabitEthernet1/0/23  unassigned      YES unset  down                  down   
Switch!#show run int g1/0/23
Building configuration...

Current configuration : 90 bytes
!
interface GigabitEthernet1/0/23
  speed 1000
end

         
SwitchA#show int g1/0/23 status

Port      Name               Status       Vlan       Duplex  Speed Type
Gi1/0/23  -                    notconnect   1            auto   1000 10/100/1000BaseTX
SwitchA#

[John Blakley]

What happens if you leave it at auto? Does it negotiate at 1000/full?

[glen.grant · Accepted solution]

Sounds like you have  a cable that doesnt have 4 good pairs in it so it will only support 100 meg.   Make sure you have the correct cable also , gig speed uses all 8 wires to operate and may be why it will only run at 100 meg as 100 meg only uses 2 pair of wires.

[kenkisare]

Thanks for your feedback.

1. if set to auto,it does not negotiate to 1000/full.

2. I going to check my cable cause three pairs failed as per the tdr test as below.

SwitchA#show cable-diagnostics tdr int g1/0/23
TDR test last run on: September 23 14:08:52

Interface Speed Local pair Pair length        Remote pair Pair status
--------- ----- ---------- ------------------ ----------- --------------------
Gi1/0/23  100M  Pair A     150  +/- 4  meters Pair A      Normal             
                Pair B     12   +/- 4  meters Pair B      Fail               
                Pair C     12   +/- 4  meters Pair C      Fail               
                Pair D     112  +/- 4  meters Pair D      Fail               
SwitchA#