like the title says , what are the pro’s and cons of GRE-IPIP-EoIP?
i’ve done bandwidth test on these 3 and they have similar outputs on that. but now i want to seperate them by pro’s and cons.
i’ve read something about their overhead :
EoIP = 42 bytes
GRE = 24 bytes
IPIP = 20 bytes
but what is better? and are there any other small or major differences ?
EoIP can carry L2 frame for transparent bridge purpose, the other two can use for routing purpose !
and what about security , i’ve read something about GRE being slightly more secure than IPIP ? why is that?
and what about the amount of tunnels a gre can accomplish against IPIP and EoIP?
The security is the same. Non-existent.
If you need security you need to use IPsec bellow whichever tunnel you choose.
i’m not talking about heavy encryptions , more like GRE is more secure because of the checksum and the key inside the GRE header?
and what about packet fragmentation and the layer 3 protocol encapsulation?
It depends only on your needs.
GRE actually can transport whatever you want. And EoIP is also GRE, with the addition of 2 bytes in the header defining a tunnel ID, so one can run more than one tunnel between 2 endpoints, and it transports ethernet frames only.
The actual overhead for GRE is 22 to 26 bytes (IP header + GRE header), depending if checksum, a key and a sequence number is used (which are optional). EoIP adds 2 more bytes to this (the tunnel ID) and of course the ethernet header.
IPIP only adds the additional IPv4 header, but can not transport anything else except IPv4.
So, if you need IPv4 only, IPIP is the best way. Multiple protocols others than IPv4 (e.g. IPv6), then GRE is the solution. Need to transport ethernet frames or you need multiple tunnels between the same endpoints - EoIP is the way to go (and can transport everything ethernet does). What’s transported and how secure it is, that’s your own problem.