High Latency between VLANs

[Imran Irshad]

Good Day,

I have installed Cisco 3560 Core Switch and 4 2960x department  Switches running VLAN

When i ping default VLAN to VLAN then ms is shoiwng ok as below but to VLAN 10,20,30 is showing high ms.

Default VLAN result 

Pinging 192.168.0.10 with 32 bytes of data:
Reply from 192.168.0.10: bytes=32 time<1ms TTL=128
Reply from 192.168.0.10: bytes=32 time<1ms TTL=128
Reply from 192.168.0.10: bytes=32 time<1ms TTL=128
Reply from 192.168.0.10: bytes=32 time=1ms TTL=128

Default VLAN to VLAN10 Result.

Pinging 192.168.40.15 with 32 bytes of data:
Reply from 192.168.40.15: bytes=32 time<10ms TTL=63
Reply from 192.168.40.15: bytes=32 time=13ms TTL=63
Reply from 192.168.40.15: bytes=32 time=24ms TTL=63
Reply from 192.168.40.15: bytes=32 time=21ms TTL=63

Could you please let me the recommendation action to solve this issue ? 

[Julio E. Moisa]

Hi,

It could be a layer 1 issue, NIC or cabling, have you tried ping to device in other vlan over the same switch where you are making ping? or disabling antivirus? other reason could be if the destination is using wireless connection. 

[Imran Irshad]

Thank you Julio for reply,

I have tried to ping  in SAME VLAN like 192.168.10.2 to 192.168.10.3, or default 192.168.0.1 to 192.168.0.2 no issue,

but from source computer 192.168.0.2 to desti computer 192.168.10.2  is showing 10 to 30 ms 

[Georg Pauwen]

Hello,

in addition to Julio's remarks, you might want to check if the core switch is the root for your VLANs. On the 3560, issue the command 'show spanning-tree vlan' for all VLANs and check for the line 'This switch is the root'...

[Imran Irshad]

HI Georag,

Thank you for replying,

i have check with show spanning-tree vlan 1default/V20/V30 on core switch and found 23 port showing 

"Root FWD 4"

[Julio E. Moisa]

Hi

You could use this command to follow the ports and reach the root:

show spanning-tree vlan <your vlan> root detail

example:

show spanning-tree vlan 10 root detail 

[Fotiosmark]

I am trying to upload new image to a cisco ISR4331.

I am at the Rommon> where I put the below commands.

rommon 2 > IP_ADDRESS=10.0.0.1
rommon 3 > IP_SUBNET_MASK=255.255.255.0
rommon 4 > TFTP_SERVER=10.0.0.2 == my pc ip tftpser
rommon 5 > DEFAULT_GATEWAY=10.0.0.2
rommon 6 > TFTP_FILE=isr4300-universalk9.16.07.02.SPA
rommon 9 > tftpdnld

monitor: command "tftpdnld" not found



I can't understand why since I already did the same thing on the same router for a different image.

[Julio E. Moisa]

Hi

I have had this issue before, but other solution is to use a compact flash reader, connect it to your computer and load the image, then install the CF on the Router and turn it on. 

[Georg Pauwen]

Post the full output for the command (for each VLAN)

show spanning-tree vlan

[Imran Irshad]

show  spanning-tree vlan 1

Gi0/21 Desg FWD 4 128.21 P2p
Gi0/22 Desg FWD 4 128.22 Edge P2p
Gi0/23 Root FWD 4 128.23 P2p
Gi0/24 Desg FWD 4 128.24 Edge P2p

show  spanning-tree vlan 10

Gi0/9 Desg FWD 4 128.9 P2p
Gi0/18 Desg FWD 4 128.18 P2p
Gi0/20 Desg FWD 4 128.20 P2p Peer(STP)
Gi0/21 Desg FWD 4 128.21 P2p
Gi0/23 Root FWD 4 128.23 P2p

show  spanning-tree vlan 20

Gi0/9 Desg FWD 4 128.9 P2p
Gi0/18 Desg FWD 4 128.18 P2p
Gi0/20 Desg FWD 4 128.20 P2p Peer(STP)
Gi0/21 Desg FWD 4 128.21 P2p
Gi0/23 Root FWD 4 128.23 P2p

[Georg Pauwen]

Hello,

if this is the output from the core switch, it means the core switch is not the root (the root switch has only designated ports).

Try and set the root manually for all VLANs:

spanning-tree vlan x root

So you end up with only designated ports on the core switch.