I try to use two ASR 1k routers to set up 464XLAT environment but find something strange on CLAT side (multiple prefix stateless NAT64). My configuration on CLAT is as following: (IOS: asr1000rp1-advipservicesk9.03.05.02.S.152-1.S2)
------------------------
ipv6 unicast-routing
!
interface GigabitEthernet0/0/0
ip address 10.1.1.1 255.255.255.0
negotiation auto
nat64 enable
!
interface GigabitEthernet0/0/1
no ip address
negotiation auto
ipv6 address 2001:CA0:1:100::81/64
ipv6 enable
ipv6 nd ra suppress
no ipv6 redirects
nat64 enable
nat64 prefix stateless v6v4 2001:CA0:1:900::/96
!
ipv6 route 2001:CA0:1:900::/96 2001:CA0:1:100::4
!
nat64 prefix stateless v4v6 2001:CA0:1:A00::/96
!
nat64 route 1.0.0.0/8 GigabitEthernet0/0/1
nat64 route 2.0.0.0/7 GigabitEthernet0/0/1
nat64 route 4.0.0.0/6 GigabitEthernet0/0/1
nat64 route 8.0.0.0/7 GigabitEthernet0/0/1
nat64 route 11.0.0.0/8 GigabitEthernet0/0/1
nat64 route 12.0.0.0/6 GigabitEthernet0/0/1
nat64 route 16.0.0.0/4 GigabitEthernet0/0/1
nat64 route 32.0.0.0/3 GigabitEthernet0/0/1
nat64 route 64.0.0.0/2 GigabitEthernet0/0/1
nat64 route 128.0.0.0/2 GigabitEthernet0/0/1
nat64 route 192.0.0.0/2 GigabitEthernet0/0/1
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I have a IPv4 host on the LAN of ASR GE 0/0/0 side to send out IPv4-only traffic.
The strange results are:
If the host address is set to 10.1.1.8/24, It can ping www.google.com.tw but fails to ping to 168.95.1.1 (public DNS Server).
However, if the host address is changed to 10.1.1.1/24, it fails to ping www.google.com.tw, but can ping 168.95.1.1
I find that the problem is caused by the stateless NAT64 router (CLAT), because in the fail case, there are v4->v6 packets log on CLAT cisco router, but I can not see any translated IPv6 packets appear on GE 0/0/1 interface (it means that the translated IPv6 packets are not sent out).
It seems there are some kind of source route ???????????
I have checked the related Cisco documents but still can not find any solutions.