Go CCIE Go!! - A Cisco Certified Internetwork Expert

I always use tunnel mode ipv6ip for these questions. Although, I don’t exactly know why! I didn’t think of using GRE and am slightly surprised it works. I was taught to use this method at a boot camp.
Another area to research some more!
Chris

—–Original Message—– From: nobody@groupstudy.com [mailto:nobody@groupstudy.com] On Behalf Of Dennis Worth Sent: 31 May 2008 15:17 To: CCIE3000 Cc: Cisco certification Subject: Re: IPV6 Tunnelling
I would add in dynamic with 6to4 tunnel to the mix. RFC 3056 should help along with :
http://www.cisco.com/en/US/docs/ios/ipv6/configuration/guide/ip6-tunnel_ps64 41_TSD_Products_Configuration_Guide_Chapter.html#wp1037465
HTH
On Sat, May 31, 2008 at 6:14 AM, CCIE3000 wrote:
> Just checking to see that I’ve got this straight in my head. > > When a question has wording along the lines of: > > Configure IPv6 tunnel over IPv4 network > > We should use tunnel mode gre ? > > From the follwoing debugs with tunnel mode ipv6ip I get the following: > l13: IPv6/IP encapsulated 150.1.3.3->150.1.1.1 (linktype=79, len=92) > *May 31 12:55:37.277: Tunnel13: IPv6/IP to classify > 150.1.1.1->150.1.3.3(len=92 ttl=253 tos=0xE0) > *May 31 12:55:37.277: Tunnel13: to decaps IPv6/IP packet 150.1.1.1-> > 150.1.3.3 (len=92, ttl=253) > *May 31 12:55:37.277: Tunnel13: decapsulated IPv6/IP packet > > With tunnel mode gre I get the following: > *May 31 12:58:11.573: Tunnel13: GRE/IP encapsulated > 150.1.3.3->150.1.1.1(linktype=79, len=124) > *May 31 12:58:11.609: Tunnel13: GRE/IP to classify > 150.1.1.1->150.1.3.3(len=124 type=0×86DD ttl=253 tos=0×0) > > Also using debug ip packet detail I’m seeing protocol 47 with GRE and > protocol 41 when ipv6ip. > > Firstly, am I correct to use mode gre and secondly any tips on what to look > for in a question to decide the tunnel mode if it’s not stated? > Thanks, > > > _______________________________________________________________________ > Subscription information may be found at: > http://www.groupstudy.com/list/CCIELab.html > > > > >
— Dennis Worth