10-02-2013 09:24 AM - edited 03-01-2019 05:41 PM
I have a Cisco AP 1262 running 15.2.4-JA1 which has IPv6 support.
I want to leave IPv6 neighbor discovery on but I want to disable router discovery so I can manually specify what default gateway to use.
You can do this on windows:
netsh inter ipv6 set interface XX routerdiscovery=disabled
I can't seem to find the command in IOS.
Thanks.
10-02-2013 11:48 AM
You do not have to do anything - by default IOS routers do not install the routes nor configure the interfaces in response to router advertisements.
if you want to do SLAAC, then you will configure "ipv6 address autoconfig", if you also want to
select default gateway based on RA, you will do "ipv6 address autoconfig default".
If you do not have this command, you will need to put all the routers manually or use a routing protocol.
10-02-2013 12:14 PM
On the contrary,
It seems my 1262 AP is doing this by default.
I did nothing but assign an IPv6 address to my AP and it was able to ping IPv6 Internet.
interface BVI1
ip address XXX.XXX.1.250 255.255.255.0
no ip route-cache
ipv6 address XXXX:XXXX:XXXX:1:FFFF:FFFF:FFFF:FFFA/64
ipv6 enable
ap#show ipv6 inter bvi1
BVI1 is up, line protocol is up
IPv6 is enabled, link-local address is FE80::462B:3FF:FE91:XXXX
No Virtual link-local address(es):
Global unicast address(es):
XXXX:XXXX:XXXX:1:FFFF:FFFF:FFFF:FFFA, subnet is XXXX:XXXX:XXXX:1::/64
Joined group address(es):
FF02::1
FF02::1:FF91:3C8D
FF02::1:FFFF:FFFA
MTU is 1500 bytes
ICMP error messages limited to one every 100 milliseconds
ICMP redirects are enabled
ICMP unreachables are sent
ND DAD is enabled, number of DAD attempts: 1
ND reachable time is 30000 milliseconds (using 30000)
ND NS retransmit interval is 1000 milliseconds
Default router is FE80::C2EA:E4FF:FE09:XXXX on BVI1
10-02-2013 12:47 PM
Ah, good point - seems like the ipv6 unicast-routing is off, and my claim indeed is incorrect for the host mode.
Several things to do:
A) just configure the ::/0 route with the appropriate interface/next hop - it will override the default which was obtained via received RA, even if the "sh ipv6 int X" will still show that.
B) make it a router, but disable all the RAs on the interface (I imagine you are bridging IPv6 to something else on the segment ?)
1) suppress all RAs on the BVI interface before enabling the routing: "ipv6 nd ra suppress all"
2) enable "ipv6 unicast-routing".
C) Alternatively, you can take care of this on the routers themselves by manipulating the lifetime - set it to zero on those that you do *not* wish to be selected as default router:
int X
ipv6 nd ra lifetime 0
This way you can affect the configuration on all the hosts at once.
--a
10-02-2013 01:19 PM
Thanks Andrew.
I can't beleive Cisco does not have this option and M$ does.
Option A is my only choice.
Option B is not avaliable on my AP.
There is no command ipv6 nd ra suppress all
There is no command ipv6 unicast-routing
ap#config t
Enter configuration commands, one per line. End with CNTL/Z.
ap(config)#inter bvi1
ap(config-if)#ipv6 nd ra suppress all
^
% Invalid input detected at '^' marker.
ap(config-if)#end
ap#ipv6 unicast-routing
^
% Invalid input detected at '^' marker.
Option C is not really applicable for my topology becuase the AP is on a trunk port on a switch operating in L3 mode and the wireless clients still need the RA to access IPv6.
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