Switch Trunking not work

[fan.yang]

Hi guys:

I am an automation engineer, and my control system is located on a network using AB Stratix switches (8300 and 8000), which I was told are running basiclly a Cisco system.

I have a layer 3 switch (SW01) on top which is located in central office, then at different buildings of my plant, I have corresponding layer 2 switches (SW02, SW03, SW04). The existing network system works well.

I am recently try to add anther layer 2 switch (SW06) into my network.

I difined the new VLAN in SW01 and SW06, then I have them connected through selected ports and then I “switchport mode trunk” for this two ports. But I cannot ping to each other after the light flash green.

I do a "show run all" on SW04 and SW06. There are some different on some configuration part, but I don't know which will be the problem that I have to correct (someone in another community mention about STP)

I attached the files below the post. Can someone take a look? Thanks in advance.

[lpassmore]

Pls confirm where you have connected SW06 (to which switch).  And pls include configuration of SW01. A diagram would be handy.

Which VLAN are your hosts on that you are trying to connect and on which switches do they sit? Did you create the VLAN in SW04?

If the comment on the SW04 trunk interface is correct it looks as if it connects to SW02.  If it, in fact does, did you create the VLAN on there also?  

[fan.yang]

The SW01 switch configuration of SW01 is attached. And I have a drawing show the details.

The SW04 is trunk back to SW01 Gi1/2. While the SW06 is designed to trunk back to SW01 Fa2/2.

The guy who configured the network is left, so I don't know if VLAN in SW04 is created on the SW04 individually.

The comment on SW04 is not correct, it is back to SW01.

Basiclly, the SW01 is the top in my central server room, where all my servers are located; SW01/02/.../06 are the switches in other buildings and connect to the equipment, like PLC. 

As I understand, each layer 2 switch should contain the VLAN that the equipment in that building belongs to; and then trunk back to SW01, and then be available to my servers, which are also connected to SW01.

[lpassmore · Accepted solution]

OK. So I am still a bit confused by the sketch but let me see if I have it:

SW06 is supposed to connect to SW01 Port Fa2/2? I haven't seen which interface on SW06 is connected (unless I missed it in the detail) but hopefully it is G1/1 or G1/2 which appear to be configured correctly. Fa2/2 on SW01 looks to be OK.

You have a spanning-tree mismatch (PVST on SW01 and MST on SW06).  This is not ideal.  I see that SW04 is also running PVST so my thought is that PVST is the preferred.  MST and PVST will operate together, but there are some notes that say MST should always be the root for any VLAN.  Since, in your scenario, SW01 should really be the spanning-tree root, I would look to change the mode of SW06.  Try that first and see how it goes unless you have a reason for selecting MST on that switch, in which case limit the VLANs down the trunk to only what you need on SW06.

In any case, spanning-tree will take 30 seconds or more to permit traffic on the trunks so make sure you have waited at least that long before trying your pings.

show spanning-tree or show spanning-tree <vlan xxx> on both sides of the link will help work out if there is an issue there.

Failing all that, give more details please:

• VLAN number (xxx) that you are trying to work with
• show interface status on SW01 and SW06
• show interface of the connected interfaces
• show interface switchport of the connected interfaces
• IP address and MAC address of source and target
• interfaces they are connected
• can you ping 172.16.0.12 from SW01?
• can you ping 172.16.0.254 from SW06?
• show ip arp vlan xxx from SW01
• show mac address vlan xxx (it might be show mac address-table or show mac-address). Use the ? for help while you are typing
• arp -a from the source and destination machines
• Can either machine ping the default gateway address (Vlan interface on SW01)?

Let's go with that and hopefully something will fall out for you.

[fan.yang]

Thank you Ipassmore, it works when I switch the STP to PVST on SW06 :)

[lpassmore]

Cheers for that. Don't forget to mark the answer as correct & rate it :)