(usagi-users 02091) Re: Different types of tunnels

[Abdul Basit <basit@xxxxxxxxxxxx>]

afaik sit is for six-in-tunnel
i beleive cisco does support 1 and 2

according to my understand, broadly speaking

automatic is replaced by 6to4
and manual is replaced by 6over4

correct me if any mistake ?

-- basit

On Wed, 15 Jan 2003, Yaniv Kaul wrote:

> Hi,
>
> I'm trying to understand what are the different types of tunnels
> available, to get IPv6 over IPv4. I found zillion terms and RFCs, not
> sure what matches what.
> To make things happier, I'm working on multiple operating systems
> (Linux, with and without USAGI; Solaris 9; Nokia IPSO 3.7; Win XP SP1,
> Cisco IOS 12.2).
> Here's what I got so far, I'd be happy to get corrections/comments. [One
> that I already know of, is that some of those tunneling techniques are
> considered deprecated.]
> Here goes:
>
> 1. Automatic, using 'compatible' address (::w.x.y.z):  Seems supported
> in Linux, if using IPV6_AUTOTUNNEL="yes" in /etc/sysconfig/network .
> Does it refer to RFC2893? If so, I'm not sure I understand it
> completely, as the RFC seems to suggest a multicast IPv4 environment is
> required.
> 2. Manual, using 'compatible' address on the link local (fe80::w.x.y.z).
> Seems supported in Linux, using
> /etc/sysconfig/network-scripts/ifcfg-sitX, where X>0.
> Is this RFC 2529? Seems like Solaris supports it, and it only (although
> RFC 2893 was written by a SUN dude). Is this a '6 over 4' tunnel?
> 3. Manual 2? - addresses are fe80::a.b.c.d.w.x.y.z, where w.x.y.z is the
> IPv4 source, and a.b.c.d is the IPv4 destination. Seen only on Nokia
> IPSO. Referred to as '6 in 4' tunnels.
> 4. '6 to 4'. RFC 3056. 2002:w.x.y.z::/48 . Supported on Linux (with
> USAGI), XP SP1, Cisco IOS, Nokia IPSO. Didn't work for me on the USAGI -
> put IPV6TO4INIT in /etc/sysconfig/network-scripts/ifcfg-eth0, nothing
> happened. I assume it's a misconfiguration on my side, though.
> 5. ISATAP - fe80::5fe:w.x.y.z . XP SP1, experimental on USAGI.
>
> Issues:
> - Not sure if Cisco supports 1 or 2, as it seems there's a mixup between
> the two.
> - Can anyone tell me what 'sit' stands for (as in "/sbin/ip tunnel add
> sit1 mode SIT...") ?
> - Can anyone tell me what is "6 in 4", what is "6 to 4" ? I assume "6
> over 4" is RFC 3056.
> - Anyone knows how to configure Nokia's "6 in 4" in Linux (item 3) ?
> - Does the use of 'compatible' addresses implies the use of RFC 2893? I
> think there's 'compatible' tunnel, which I could not find defined
> exactly (for example, Cisco supports it, but does not support RFC 2529)
> and there's RFC 2893.
>
> Sorry for all the mixup, hope someone can shed some light on this, or
> refer me to an ultimate source...
>
> TIA,
> Y.