Re: Difference between tunnel modes: GRE/IP versus IPv6/IP

Thanks for your time checking this. From a traffic perspective I wonder
if there is any restrictions on an IPv6/IP tunnel over a straight GRE
tunnel.

regards Andy

garry baker wrote:
> ' difference in functionality ' that i can see from a quick debug ip packet
> is
>
> GRE/IP = len 124, sending, proto=47
> IPv6/IP = len 120, sending, proto=41
>
> changing the way the tunnel is encapusaled, in size at least....
>
> Tunnel1 is up, line protocol is up
> Hardware is Tunnel
> MTU 1514 bytes, BW 9 Kbit/sec, DLY 500000 usec,
> reliability 255/255, txload 1/255, rxload 1/255
> Encapsulation TUNNEL, loopback not set
> Keepalive not set
> Tunnel source 1.1.1.12, destination 1.1.1.11
> Tunnel protocol/transport GRE/IP
>
> R11#ping 3001::12 r 1
> Type escape sequence to abort.
> Sending 1, 100-byte ICMP Echos to 3001::12, timeout is 2 seconds:
> !
> Success rate is 100 percent (1/1), round-trip min/avg/max = 80/80/80 ms
>
> R12#
> IP: s=1.1.1.12 (Tunnel1), d=1.1.1.11 (FastEthernet0/0), len 124, sending,
> proto=47
>
>
>
> R12#sh int tunnel 1
> Tunnel1 is up, line protocol is up
> Hardware is Tunnel
> MTU 1514 bytes, BW 9 Kbit/sec, DLY 500000 usec,
> reliability 255/255, txload 1/255, rxload 1/255
> Encapsulation TUNNEL, loopback not set
> Keepalive not set
> Tunnel source 1.1.1.12, destination 1.1.1.11
> Tunnel protocol/transport IPv6/IP
>
> R11#ping 3001::12 r 1
> Type escape sequence to abort.
> Sending 1, 100-byte ICMP Echos to 3001::12, timeout is 2 seconds:
> !
> Success rate is 100 percent (1/1), round-trip min/avg/max = 68/68/68 ms
>
> R12#
> IP: tableid=0, s=1.1.1.11 (FastEthernet0/0), d=1.1.1.12 (FastEthernet0/0),
> routed via RIB
> IP: s=1.1.1.11 (FastEthernet0/0), d=1.1.1.12 (FastEthernet0/0), len 120,
> rcvd 3, proto=41
> IP: s=1.1.1.12 (Tunnel1), d=1.1.1.11 (FastEthernet0/0), len 120, sending,
> proto=41
>
>
> --
> Garry L. Baker
>
> "There is no 'patch' for stupidity." - www.sqlsecurity.com
>
>
> On Tue, Feb 23, 2010 at 12:47 PM, Andy Reid <ccie_at_reid.it> wrote:
>
>
>> Hi All,
>>
>> Could someone explain to me the difference between GRE/IP and IPv6/IP
>> tunnel modes when the GRE/IP tunnel has an IPv6 address configured at each
>> end.
>>
>> Both tunnel modes have an IPv4 source and destination address. The only
>> difference I can spot is in the "show int tunnel x" command where the Tunnel
>> protocol/transport is shown differently. I can't spot any difference in
>> functionality at the moment.
>>
>> regards Andy
>>
>>
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Received on Tue Feb 23 2010 - 21:00:52 ART