weird issue on "LAN extension"

[m1xed0s]

Hey, guys

Today ran into a weird issue on LAN extension between 2 356 switches. My understanding of the LAN extension is just a QinQ metro Ethernet on fibre.

We have a office in another city close by and all the servers are hosted in our office. I have 2 vlans (111 and 200) configured to send over the fibre. It is just normal trunking, nothing fancy. I can ping from one end to the other on vlan 111 all the time; I can also ping from one end to the other end on vlan 200 but not all the time. I would need to reset the trunk interface on either Switch if i could not ping on vlan200 over fibre. I can see the arp entries on both switches for device on vlan 200 even ping stops working though.

I called ISP and the guy said nothing is wrong on their network. If circuit works for one vlan, it will also work for the other. I could agree with him but I still think there is something dropping packets, otherwise how can it suddenly lost connection and reset interface fixed issue?

Any suggestion? Please advise.

[Reza Sharifi]

Hi,

Do you have additional fiber port in your switches?  If yes, try a different fiber port with the same config and test again.

HTH

[m1xed0s]

Sorry, I might confused you.

There are 2 ISP devices (also cisco switches) connected behind their fibre converter. I connect our switch to the ISP switch and then to the fibre convertor to ISP network.

So it will be something like:

My LAN<->local 3560<->ISP edge switch<->fibre convertor<-ISP FIBRE NETWORK->fibre convertor<->ISP edge switch<->remote 3560<->my remote LAN.

[m1xed0s]

No one ever run into similiar issue?

Still waiting...