On 9 March 2016 at 20:59, Nick Hilliard <nick@foobar.org> wrote:
There is a critical difference between these two situations. In the case of an arp sponge, the ixp operator has control of both the polling and the workaround. In the case of mtu management they would only have control of the polling, not the remediation. The point I was making is that an ixp operator can only control their own infrastructure. Once it's someone else's infrastructure, all you can do is make polite suggestions.
If customer does not react, put it on quarantine VLAN. This can be automated too. Wrong MTU => open internal case, contact customers email, no customer response in N days, quarantine VLAN. Even the most outrageous success stories in the world, majority of the people would have said before attempting that it won't work, because that is safe and easy. And usually they are right, most things don't work, but it's very difficult to actually know without trying what works and what does. Luckily we have actual IXPs running big and small VLAN MTUs, even without this monitoring capability, and it Internet still works. -- ++ytti