Max MTU size for inter site DC links using OTV/VXLAN

[neil_titchener]

Hi All,

I'm looking into setting up a layer 2 virtual link between two DCs and I've read that OTV requires a minimum MTU of 1542 and does not support fragmentation while VXLAN requires an minimum MTU of 1550 and does support fragmentation.  As this will connect two DCs which would likely use MTUs of around 9126 bytes I'm assuming that the virtual links would also need to allow the same size MTUs to create the same network characteristics between the two DCs. 

My question is which ISPs and what products offer this in the UK?  I've read that BTs 21CN network which offers IPConnect as the primary network offering has a maximum MTU of 1500 bytes.  Does BT or any other provider offer links with higher MTUs?

Thanks for taking the time to read this and hopefully provide some answers :-)

[neil_titchener]

I have found a document that states the ASR 1001 routers can fragment OTV packets but please add anything to the blog that you feel will add to the conversation.