Possible loops

[graytech]

See some significant spikes on our network, running a few commands after some googling, Below are some examples on what I am seeing, any assistance on how to remediate these? 

show spanning-tree detail | inc ieee|occur|from|is exec
VLAN0001 is executing the ieee compatible Spanning Tree protocol
Number of topology changes 25630 last change occurred 02:10:37 ago
from GigabitEthernet2/1/2
VLAN0010 is executing the ieee compatible Spanning Tree protocol
Number of topology changes 24998 last change occurred 1d07h ago
from GigabitEthernet1/0/16
VLAN0011 is executing the ieee compatible Spanning Tree protocol
Number of topology changes 217 last change occurred 1d07h ago
from GigabitEthernet1/0/16
VLAN0020 is executing the ieee compatible Spanning Tree protocol
Number of topology changes 25062 last change occurred 1d07h ago
from GigabitEthernet1/0/16
VLAN0030 is executing the ieee compatible Spanning Tree protocol
Number of topology changes 24696 last change occurred 1d07h ago
from GigabitEthernet1/0/16

interface GigabitEthernet1/0/16
description "WAP"
switchport trunk native vlan 130
switchport mode trunk
spanning-tree portfast
spanning-tree bpduguard enable

interface GigabitEthernet2/1/2
switchport mode trunk

Vlan130 is up, line protocol is up
MTU 1500 bytes, BW 1000000 Kbit/sec, DLY 10 usec,
5 minute input rate 643000 bits/sec, 144 packets/sec
5 minute output rate 1143000 bits/sec, 200 packets/sec

GigabitEthernet2/1/2 is up, line protocol is up (connected)
MTU 1500 bytes, BW 1000000 Kbit/sec, DLY 10 usec,
5 minute input rate 84000 bits/sec, 32 packets/sec
5 minute output rate 96000 bits/sec, 52 packets/sec

[Reza Sharifi]

Where do you see significant spikes?

5 minute input rate 643000 bits/sec, 144 packets/sec
5 minute output rate 1143000 bits/sec, 200 packets/sec

1143000 is just over a 1Mbps (1.143) on a gig interface.

5 minute output rate 96000 bits/sec, 52 packets/sec

Also, the above number is less than 1Mbps

So, this interface does not have much load on it.

HTH

[graytech]

I am very new to cisco troubleshooting. the spikes itself is from a third party application (cacti). Where specific VLAN/ Trunk Ports Outbound/Inbound interfaces are hitting 100Mbps at the same time. I was looking to see where on the switch I can see this.  

Vlan20 is up, line protocol is up
MTU 1500 bytes, BW 1000000 Kbit/sec, DLY 10 usec,
5 minute input rate 545461000 bits/sec, 52591 packets/sec
5 minute output rate 1105733000 bits/sec, 106975 packets/sec

[Reza Sharifi]

Cacti will show that the amount of traffic on the interface but it will not be able to tell you what device/application is causing high traffic. If you want to see what device/application is producing high traffic, you would need some sort of monitoring system like SolarWinds to see the top 5 or 10 talker on the dash. 

HTH

[graytech]

Are there any commands I can run on the switch to see why the suspected ports are affecting other ports that are also on the same vlan/trunked? These ports are directly connected to a single host some are WAP and some Servers. 

[paul driver]

Hello

Make sure all your access-ports are spanning-tree edge ports ( spanning-tree portfast) as if they dont then this can cause unwarrented stp transitions.

[graytech]

Thank you. How about my uplink trunk ports? I am seeing a lot of TCNs for my uplink ports, how do I get rid of these?

Core:

interface GigabitEthernet1/0/24
description "uplink p48 from switch"
switchport access vlan 100
switchport mode trunk
channel-group 1 mode active
end

interface GigabitEthernet2/0/24
description "uplink p47 from switch"
switchport access vlan 100
switchport mode trunk
channel-group 1 mode active
end

Switch:

interface GigabitEthernet0/48
switchport mode trunk
channel-group 1 mode active

interface GigabitEthernet0/47
switchport mode trunk
channel-group 1 mode active

VLAN0090 is executing the ieee compatible Spanning Tree protocol
Number of topology changes 24255 last change occurred 6d14h ago
from GigabitEthernet0/48
VLAN0100 is executing the ieee compatible Spanning Tree protocol
Number of topology changes 24256 last change occurred 6d14h ago
from GigabitEthernet0/48

VLAN0200 is executing the ieee compatible Spanning Tree protocol
Number of topology changes 24256 last change occurred 6d14h ago
from GigabitEthernet0/48

[Cristian Matei]

Hi,

    As nowadays we should be running RSTP/MSTP, I've seen  lot of weird issues with plain old STP and TCN issues, where the STP Root Bridges fails to acknowledge these. The simplest solution for you is to:

         - run RSTP on all devices

         - configure all ports facing non-switches as portfast

Regards,

Cristian Matei.