ISATAP IPV6 testing

[BeechLiam]

Hi folks,

If someone could clarify my configuration here for an ISATAP tunnel on a 2811 Router, directly connected to a Windows XP machine (LAB Environment). I have sourced the tunnel to the FA0/0 of the Router and applied a route on the Window XP Client as follows.netsh interface ipv6 isatap set router 10.10.10.1. The ipv4 address 10.10.10.1 is pingable from the XP Client ,but I dont see any route for the IPV6 tunnel on the XP client& I cant IPV6 ping the Windows XP client, from the 2811 Router. IPV6 is installed on the client.

Thanks for any advise in advance.

[Giuseppe Larosa]

Hello Liam,

the host portion of the IPv6 ISATAP address should be:

0000:5EFE + 32bits equivalent of IPv4 address of tunnel source interface.

see

http://www.ietf.org/rfc/rfc4214.txt

section 6.1 isatap interface identifiers

in your case it should be:

3FFE:80C0:22C:817F:0000:5EFE:0A0A:0A01

and link local should be:

FE80::0000:5EFE:0A0A:0A01

instead we see:

SH IPV6 INT BRief

FastEthernet0/0 [up/up]

unassigned

FastEthernet0/1 [administratively down/down]

unassigned

Tunnel1 [up/up]

FE80::21D:70FF:FEBE:C190

3FFE:80C0:22C:817F:21D:70FF:FEBE:C190

the host portion of this /64 and of link local is :

21D:70FF:FEBE:C190

that is not correct so there is no communication between the two.

this looks like to be an EUI taken from a MAC address instead

see

http://www.ietf.org/rfc/rfc3513.txt

appendix A.

However, config examples don't show additional commands to force/change the OUI selection for the tunnel interface:

http://www.cisco.com/en/US/docs/ios/ipv6/configuration/guide/ip6-tunnel.html#wp1055566

This may be an IOS issue and I would suggest you to try another IOS image on the router.

ISATAP is based on the presence of the ipv4 address in the less significant 32 bits missing this cause the issue.

Hope to help

Giuseppe