Thanks wmf I should have included the reference and have added it. There's a lot more that I don't cover e.g. PMTUD black hole routers, etc. But the article is

Thanks wmf I should have included the reference and have added it. There's a lot more that I don't cover e.g. PMTUD black hole routers, etc. But the article is targeted at an intermediate level audience, so leaving those out for now.