GRE can transport more protocols such as IPX in addition to IP, whereas IPIP is only limited to IP protocol.
The tunnel mode allows any type of traffic to be transported because it has nothing to do with the content of the packet as long as it can support the encapsulation for that protocol. So IPIP supports encapsulation for all types of IP traffic irrespective of it being multicast or unicast. GRE can encapsulate more layer three protocols and hence can support more traffic types. Hope this was helpful. Thanks Suresh On 4/23/08, Sharath Samanth <[EMAIL PROTECTED]> wrote: > oops!! hit the send button before finishing the mail.! Sorry! > > > > I was wondering what exactly is the technical difference between IPIP and > GRE tunnels and Why GRE is most preferred. > My initial thought was GRE was the only tunnel protocol supported Multicast > and adds 24 bytes of header to the existing payload. > But I configured an IPIP tunnel and OSPF ran just fine in the default point > to point mode using multicast hellos. > So why is GRE popular choice that IPIP? > > Sharath > > > On 4/23/08, Sharath Samanth <[EMAIL PROTECTED]> wrote: > > > > Hi All, > > > > I was wondering what exactly is the technical difference between IPIP and > GRE tunnels and Why GRE is most preferred. > > My initial thought was GRE was the only tunnel protocol supported > Multicast and adds 24 bytes of header to the existing payload. > > But > >
