Sharing already used VLAN to be used by other ISP

[tanzeemsarwar11@gmail.com]

I work in  an ISP multiple times i have encounter that other ISPs wants to run his customer through my network and they share the VLAN ID that i can't allow for them because it has been used by my network. i want to ask if there is any possibility to use the same Vlan for both ISP.

[Mark Elsen]

 - Not at all advisable.

M.

[tanzeemsarwar11@gmail.com]

my colleague told me that QinQ can serve the purpose.?

is it right for double tagging or QinQ for being the solution.

[Georg Pauwen]

Hello,

QinQ would be an option, as it would allow you to transport customer VLANs through your network. What specific topology would you need to apply this to ?

IEEE 802.1Q Tunneling (QinQ) and L2PT on L2

https://www.cisco.com/c/en/us/td/docs/routers/access/ISRG2/software/feature/guide/QinQ_L2PT.html