Hello folks, First of all, thank you all for this amazing debate. So many important ideas were exposed here and I wish we keep going on this. I've seen many opposition to my proposal but I still remain on the side of jumbo frame adoption for IXP. I'm pretty confident there is no need for a specific MTU consensus and not all IXP participants are obligated to raise their interface MTU if the IXP starts allowing jumbo frames. One of the reasons I'm so surprised with concerns about compatibility and breaking the internet I've seen here is the offers I get from my IP transit providers: half of them offered me jumbo frame capable ports by default, it wasn't a request. When this subject became important to me and I open support tickets, half of them replied something like 'You don't need to request it. From our end the max MTU is X'. The lowest X I got was 4400 and the highest 9260 bytes. All my Tier-1 providers already provided me jumbo frames IP transit. Even my south american IP Transit provider activated my link with 9k MTU by default. So we have Tier-1 backbones moving jumbo frames around continents, why in a controlled L2 enviroment that usually resides in a single building and managed by a single controller having jumbo frames is that concerning? Best regards, Kurt Kraut 2016-03-09 19:22 GMT-03:00 Tassos Chatzithomaoglou <achatz@forthnet.gr>:
I must be missing something very obvious here, because i cannot think of any reason why an IXP shouldn't enable the maximum possible MTU on its infrastructure to be available to its customers. Then it's clearly customers' decision on what MTU to use on their devices, as long as:
* It fits inside IXP's MTU * It suits with any other customer's (exchanging traffic with) MTU
-- Tassos
Hi,
I'm trying to convince my local Internet Exchange location (and it is not small, exceed 1 terabit per second on a daily basis) to adopt jumbo
Kurt Kraut via NANOG wrote on 9/3/16 16:26: frames.
For IPv6 is is hassle free, Path MTU Discovery arranges the max MTU per connection/destination.
For IPv4, it requires more planning. For instance, two datacenters tend to exchange relevant traffic because customers with disaster recovery in mind (saving the same content in two different datacenters, two different suppliers). In most cases, these datacenters are quite far from each other, even in different countries. In this context, jumbo frames would allow max speed even the latency is from a tipical international link.
Could anyone share with me Internet Exchanges you know that allow jumbo frames (like https://www.gr-ix.gr/specs/ does) and how you notice benefit from it?
Best regards,
Kurt Kraut