I have been thinking of this for a while, but have not yet received clarity. How does the Internet work? Specifically if I get Internet service from a provider, how can they provide Transit or Any-to-Any connectivity, by simply connecting with one or multiple upstream transit providers? Surely an agreement in some form would have to be made to connect some small ISP or Enterprise on the other side of the globe to myself. Do Tier 1 providers come into play here. What about peering? Is it a requirement for certain ISPs to peer with others to provide said Transit service? Any URLs provided for further reading would be much appreciated. something something BGP? BGP would be the protocol of the Internet s/protocol/routing protocol BGP would be the routing protocol of the Internet to what end is the Internet a best effort service and where to Service Level agreements or Guarantees come in to play? you ask complicated questions mnathani :-) tier 1 providers all share each others routes with each other tier 2 providers pay tier 1 to route their traffic a small isp will connect to a tier 1, tier 2 or tier 3 provider generally tier2s make sure their routes get to tier 1, tier 3 providers generally peer even more than tier 2, generally with open peering policy. so tier 3 providers may utilise more than one tier 2 provider, or a combination of tier 1 and tier 2, sometimes adding value, and sometimes just aggregating traffic for better pricing at smaller commits. tier2 first priority -> peers, last resort -> default out to tier 1 ? cogent and he.net are considered tier 2 provider, anre they refuse to exchange ipv6 traffic between themselves atm. policies of where to send stuff can vary by provider. most people use "lowest cost" routing. although some like to carry traffic. but yeah generally speaking tier 2 first priority customers, second priority peers, third priority transit. how common are internet islands in the ipv4 internet? not common well not for normal operation. there are some routes that aren't distributed on the wider internet, but can occasionally leak to some providers. like subnets that internet exchanges use generally should use real IP address space, but not be distributed globally like can you route to 192.203.154.0/24 ? the answer shoudl be no, but some providers here let you :) 5 ae2-6169-bdr01-tor.teksavvy.com [192.0.254.75] reports: Destination net unreachable. 5 hops in suggests that your provider only starts having full tables at hop 5 :) out of curiosity do you get the same distance to say 192.168.69.69 liquidweb has a loop to that destination a loop? people can sometimes block rfc1918 addresses before unknown routes routing loop as people like to send random traffic there :/ and you don't need a full route table to block they really shouldn't loop to it though it should just drop that 69.69 ip request time out after 1 hop it should timeout from my residential connection ok so yeah they drop it early liquidweb uses Ips like pts/6 10.30.4.110 for management from their side what about 255.0.0.4 say 1 Transmit error: code 1231. 100.64.1.1? lol liquidweb has the same routing loop for 255.* they probably have default route out another link in case their bgp dies why are you using liquidweb? arp doesn't do that :) they had a good price including cPanel and management no v6 though, so I setup an he.net tunnel mercutio: thank you for the How Internet Works Explanation. there' a lot more complications :) but that's about the essence