Strange Layer 2 path

[Valentin Hutanu]

Hello,

I have a strage Layer 2 path between 2 switches.

Switch A - a 3550 running Version 12.2(44)SE - ospf routing

Siwth B - a 3750 running 12.2(55)SE3 - no routing protocol, no default gateway

There is a layer 2 trunk connection (ethercahnnel) between them, all Vlans allowed.

Both switches have Vlans 74 and Vlan 562

Host 1 connected to Switch A on vlan 562 with ip address 10.74.1.1

Host 2 connected to Switch B on vlan 562 with ip address 10.74.1.2

When I run: traceroute mac ip 10.74.1.1 10.74.1.2 the traffic goes via interface Vlan 74 (which has an ACL on it and blocks some traffic)

My question is:

Why is the Layer 2 path goes outside Vlan 562 and via Vlan 74 ?

Could it be related to the fact that all the Layer 3 Vlan interfaces on Switch A have the same mac address (a bug in that Ios version)?

[Chandhuru sekaran marimuthu]

Dear Valentin Hutanu,

     As you had quetioned on Layer 2 path goes outside the vlan from the corresponding Vlan?

     My thought was that may be you wrongly mentioned the default gateway and also didn't mention this command in Layer 2 switch may be possible

# Switchport access vlan 74

# Switchport mode access

     And also please find the attachment of Small intervlan architecture in a PT.

Thanking You,

With Regards,

Chandhuru Sekaran.M