Hello, I thought for any type of IP packet to go out onto the internet Zone (passed the local default gateway) that the packet needed to use either TCP or UDP to accomplish transportation?
I always seem to come up with the weirdest questions that I never see other people ask. Oh well.. I'll take that as a good thing. Heh.. :P This has actually been a source of unanswered confusion for some time now and I just forget to ask. Using the 7 layer OSI model in my explanations below. For some reason I always assumed that for anytype of IP packet to be routed out to the internet that you needed a Layer 4 helper (TCP or UDP) to acheive the transport? Is that true or can just IP layer 3 protocols treverse the internet with out the need for a Layer 4 transport helper? Take ICMP for example (a ping). This is a Layer 3 protocol. Now, I thought that "windows" pc's used tcp/icmp to transport pings or tracert's and linux/unix (to include Cisco routers) pc's used udp/icmp to transport pings or traceroute's. After running Ethereal and watching a packet dump in real time, I only saw ICMP being used and NO UDP or TCP. Is ethereal missing something or am I? If some types of IP packets don't need Layer 4 transport helpers like Tcp or Udp then what are some examples (or types of apps) that utilize only IP, and still get from point A to point B without the help of Tcp or Udp. Thanks, Joshua Banks __________________________________ Do you Yahoo!? Free Pop-Up Blocker - Get it now http://companion.yahoo.com/ -- [EMAIL PROTECTED] mailing list
