I not sure how it all goes together, but I do know there are more IP protocols than I first realized. TCP and UDP are two transport protocols over IP and ICMP is a seperate one. There is also AH/IP and ESP/IP used for VPNs (protocol ids of 51 and 50). As I understand it IP is just the addressing system and transport or low level functionallity (TCP, UDP, ICMP, AH, ESP) works under IP (more or less using IP for address and routing). As far as the protocols we are used to seeing (POP3, SMTP, HTTP, ...) are within the application layer (I believe... it been awhile since I've looked at the protocol layers) and require TCP or UDP for transportation. The other protocols seem to have more specific payloads.
IP protocols: TCP/IP - Generic payloads with redelivery if errors UDP/IP - Generic payloads with no error checking ICMP/IP - Specific payloads for network information/testing AH/IP - Specific payload; IPsec Authenication Header ESP/IP - Specific payload; Encapsulated Security Payload ... and I'm sure there are more defined out there. I hope this make some sense to you ;) Ron On Thu, 2003-12-04 at 20:39, Joshua Banks wrote: > 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 >
signature.asc
Description: This is a digitally signed message part
