IPv6 Global Prefix RA question from R1 to R2

LinoCatucci

Hello,


I've a questiona about IPv6 Global Prefix RA.
I have 2 routers (r1 and r2) connected via fastethernet0/0 interface.
On the first router i have gone trough the ipv6 set up:
1. I have create a ipv6 address: #ipv6 address 2001:aaa:bbbb:cccc::/64 eui-64
2. told the router that it can route ipv6: #ipv6 unicast-routing
Below is a #show ipv6 interface on R1:


FastEthernet0/0 is up, line protocol is up
IPv6 is enabled, link-local address is FE80::CA00:10FF:FE84:0
Global unicast address(es):
2001:AAA:BBBB:CCCC:CA00:10FF:FE84:0, subnet is 2001:AAA:BBBB:CCCC::/64
Joined group address(es):
FF02::1
FF02::2
FF02::1:FF84:0

On the second router I have gone trough the ipv6 steps:
1. I have enable ipv6: #ipv6 enable.
I do see that the link-local address has been created: FE80::CA02:10FF:FE84:0
Below is a # show ipv6 interface on R2:


FastEthernet0/0 is up, line protocol is up
IPv6 is enabled, link-local address is FE80::CA02:10FF:FE84:0
No global unicast address is configured
Joined group address(es):
FF02::1
FF02::2
FF02::1:FF84:0


My question is as follows: why doesn't get Router2 the global prefix information in the ipv6 address from Router 1
I do see a RA send from R1 to R2.


R1#


*Mar 1 00:40:37.455: ICMPv6-ND: Sending RA to FF02::1 on FastEthernet0/0
*Mar 1 00:40:37.455: ICMPv6-ND: MTU = 1500
*Mar 1 00:40:37.455: ICMPv6-ND: prefix = 2001:AAA:BBBB:CCCC::/64 onlink autoconfig
*Mar 1 00:40:37.455: ICMPv6-ND: 2592000/604800 (valid/preferred)
*Mar 1 00:40:37.455: IPV6: source FE80::CA00:10FF:FE84:0 (local)
*Mar 1 00:40:37.455: dest FF02::1 (FastEthernet0/0)
*Mar 1 00:40:37.455: traffic class 224, flow 0x0, len 104+1396, prot 58, hops 255, originating
*Mar 1 00:40:37.455: IPv6: Sending on FastEthernet0/0


R2(config)#
*Mar 1 00:39:42.275: ICMPv6-ND: Received RA from FE80::CA00:10FF:FE84:0 on FastEthernet0/0


What I also see is that R1 is getting RA from R2:
R1#
*Mar 1 00:47:56.199: ICMPv6-ND: Received RA from FE80::CA02:10FF:FE84:0 on FastEthernet0/0


many thanks in advance,
Lino

fsanyee

on R2's fa0/0: ipv6 address autoconfig

LinoCatucci

Hi fsanyee,

What does ipv6 address autoconfig exactly do?

fsanyee

it configures an ipv6 address automaticaly on the interface (using the advertised prefix + eui).

LinoCatucci

hi fsanyee,
thanks, that did the trick. I do see now RS and RA coming in. Also a nice global prefix.