weird VLAN issue - what am I missing?

Hi all,

Let me start with the network description. There are two Cisco 3560 switches (A) and (B). Switch A is the "core" switch and carries multiple VLANs (5, 20, 82 and 100). Switch B is connected to switch A with a fiber link (ports on both switches are set to trunk and allow all VLANs to traverse them. The native VLAN is 100). Switch A has an IP address set on VLAN 100: I have manually created VLANs (10, 15, 19, 82 and 100) on switch B (has a different VTP domain than switch A). However, I did not create the "logical" interfaces for these VLANs on switch B (and thus these VLANs do not have IP addresses assigned to them). I have set one physical port on switch B to be in the access mode and VLAN 100. There is a Windows system with the static IP address of attached to it.

I am able to ping VLAN 100 interface ( on switch A from switch B, but the following do not work:

- I cannot ping (Windows workstation connected to switch B) from switch A

- I cannot ping (Windows workstation connected to switch B) from switch B

- I cannot ping from the Windows workstation connected to switch B.

What am I missing here? Please advise.

Thanks, AP

Reply to
Adam Przestroga
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Nothing weird here about vlans.

Since switch "B" isn't doing any routing, so nothing on that switch will be able to ping anything connected to switch A unless the ports set to access vlan 100.

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Sorry Thrill5, but I do not get it. How come the workstation connected to switch B cannot ping anything connected on switch A (and switch A itself)? Also how can this be corrected?

Are you saying that this is happening because I did not assign IP address to VLAN 100 on switch B?

I would appreciate more information on this.

Reply to
Adam Przestroga

This doesn't sound like a routing issue to me.

As you have different VTP domains at each end, DTP will not work so you may need to configure the trunk with nonegotiate.

Does 'sh int trunk' show the link between switches as trunking and STP forwarding for VLAN 100?

In a failing scenario (say pinging workstation from switch A), does ARP get resolved for the target IP?

Cheers, /Phil

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