ssh -6 error(s)

[Zach Wilkinson]

Yeah, I read about ping6 -I in the Berringer HOWTO and I was able to get
that to work.
However, I read in some RFC that site local addresses were going to be
deprecated, so I figured link local addresses would be usable similar to
APIPA addresses.  If not, that leaves only global addresses which no US
broadband provider will ever hand out.

How are networks suppose to use IPv6 without being connected to the v6
Internet?

Zach

----- Original Message ----- 
From: "Felipe Alfaro Solana" <felipe_alfaro at linuxmail.org>
To: <fedora-list at redhat.com>
Sent: Tuesday, January 13, 2004 3:38 AM
Subject: Re: ssh -6 error(s)


> On Tue, 2004-01-13 at 00:25, Zach Wilkinson wrote:
> > Just the default after modprode ipv6
> >
> > [root at server root]# ifconfig -a
> > eth0      Link encap:Ethernet  HWaddr 00:40:F4:57:87:63
> >           inet addr:192.168.1.100  Bcast:192.168.1.255
Mask:255.255.255.0
> >           inet6 addr: fe80::240:f4ff:fe57:8763/64 Scope:Link
>                                                           ^^^^
> The problem you're seeing is the same I had when starting to use IPv6.
> IPv6 supports stateless autoconfiguration and has some peculiarities.
>
> For what I've seen, it seems you are using link-local addresses. The
> problem here is that all link-local addresses have the same network
> prefix: fe80/10 (although Linux seems to use fe80::/64), which makes
> impossible to know how to route packets when not specifying an outgoing
> interface. If you have two network interfaces, both have a network
> prefix of fe80::/10, so when trying to send out a packet to another
> link-local address, how do you know which interface the packet should go
> out, if you have two routing entries with a prefix fe80::/10?
>
> When you using ping6 with a link-local addresses, you must supply the -I
> <interface> argument to ping6 to specify which outgoing interface to use
> for sending out the ICMPv6 ECHO packets and resolve the ambiguity.
>
> # ping6 -I eth0 fe80::240:f4ff:fe57:8763
>
> Also, link-local addresses are mainly used for autoconfiguration, like
> prefix network assignment, using DHCPv6, using Router Discovery or
> Neighbour Discovery. They are not normally used to high-level
> communications. If you want to communicate clients using TCP/IPv6,
> you'll need to assign both your server and workstation both IPv6
> addresses with a greater scope, like a Site-local or Global address.
> Site-local and Global addresses do have specific network prefixes and
> both create specific routing entries, so packets can be sent and
> received without having to specify and outgoing interface.
>
> Site-local addresses are similary to private IPv4 addresses as used
> today in private LAN's, like 10.0.0.0/8, 172.16.0.0/12 or
> 192.168.0.0/16, are unique to a routing domain, but not unique on the
> global Internet, that is, won't escape their own routing domain. Global
> addresses are unique on the whole Internet and are routable, that is,
> they can pass through router domains.
>
> Site-local addresses have the fec0::/64 prefix, while global addresses
> usually have prefixes in the 2000::/64 range, as currently specified by
> IANA during the transition from IPv4 to IPv6.
>
> You can manually assign an IPv6 address to your interfaces by modifying
> /etc/sysconfig/network-scripts/ifcfg-ethX, or by setting up an IPv6
> Router Advertising daemon on your LAN segment, like radvd or zebra. In
> my case, I opted out for zebra, as it also offers RIPng and BGP4 routing
> protocols in addition to perform router advertising.
>
> Hope this helps.
>
>
>
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