GRE tunnel and transport protocol

[sarahr202]

  Hi everybody

Please consider the following example:

ipv4 network---R1----ipv6 network-----R2--ipv4 network

I want to establish a gre a  tunnel between R1 and R2  so ipv4 routes can be exchanged over this tunnel between R1 and R2.

The question is when using GRE tunnel, can the transport protocol be ipv6  i.e the protocol which will carry encapsulated ipv4 packet between R1 and R2 ?

Or GRE requires the transport protocol be ipv4.

Thanks and have a great weekend.

[sarahr202]

the transport protocol can be ip ( which refers to ipv4) or ipv6 for gre tunnel.

thanks

[Abzal · Accepted solution]

Hi,

IPv6 can be transport and IPv4 passenger protocol in payload.

Example.

R1:

ipv6 unicast-routing

ipv6 cef

int lo1

ip add 192.168.1.1 255.255.255.0

no shut

interface FastEthernet0/0

no ip address

duplex auto

speed auto

ipv6 address 2001:DB8:1111:2222::1/64

end

interface Tunnel0

ip address 10.0.0.1 255.255.255.252

tunnel source FastEthernet0/0

tunnel destination 2001:DB8:1111:2222::2

tunnel mode gre ipv6

ip route 192.168.2.0 255.255.255.0 tun0

R2:

int lo1

ip add 192.168.2.1 255.255.255.0

no shut

interface FastEthernet0/0

no ip address

duplex auto

speed auto

ipv6 address 2001:DB8:1111:2222::2/64

end

interface Tunnel0

ip address 10.0.0.2 255.255.255.252

tunnel source FastEthernet0/0

tunnel destination 2001:DB8:1111:2222::1

tunnel mode gre ipv6

ip route 192.168.1.0 255.255.255.0 tun0

Hope it will help.

Best regards,
Abzal