Stateful NAT Translation Table not exchanged

[ps12]

I have IP SLA running in the north-bound [A]. The redundancy works fine, however, on Router 1 and 3 I have configured Stateful NAT for the traffic leave out [B]. The NAT translation occurs but the NAT tables are not exchanged between router 1 and 3. 

I read that asymmetric routing is not supported in IP-SLA. Just want to confirm where should the asymmetry not be? In part A of the network or part B?  

In my network design, there is asymmetry only in B network, A network section has no asymmetry. Topology image is attached and sharing my configurations below- 

On Router 1-

ip access-list extended BLOCK_.65_.17_IP
deny ip any host 172.16.15.65
deny ip any host 172.16.15.17
permit ip any any
int FastEthernet0/1
ip access-group BLOCK_.65_.17_IP in


ip access-list standard NAT 
permit 188.115.126.192 0.0.0.63 
permit 188.115.127.192 0.0.0.63 

ip nat pool NAT 59.99.99.57 59.99.99.57 prefix-length 30
ip nat inside source list NAT pool NAT mapping-id 1 overload

ip nat stateful id 1
primary 172.16.15.50
peer 172.16.15.62
mapping-id 1

On Router 3 - 

ip access-list extended BLOCK_.53_.9_IP
deny ip any host 172.16.15.53
deny ip any host 172.16.15.9
permit ip any any
int FastEthernet0/1
ip access-group BLOCK_.53_.9_IP in


ip access-list standard NAT 
permit 188.115.126.192 0.0.0.63 
permit 188.115.127.192 0.0.0.63 

ip nat pool NAT 59.99.99.57 59.99.99.57 prefix-length 30
ip nat inside source list NAT pool NAT mapping-id 1 overload

ip nat stateful id 1
backup 172.16.15.50
peer 172.16.15.62
mapping-id 1

The SNAT Translation on R1 nut nothing on R3-

R1#sh ip nat translations
Pro Inside global Inside local Outside local Outside global
icmp 59.99.99.57:55 188.115.126.193:55 172.16.15.58:55 172.16.15.58:55
icmp 59.99.99.57:54 188.115.127.193:54 172.16.15.14:54 172.16.15.14:54

SNAT Distribution- 

R1#sh ip snat distributed verbose

Stateful NAT Connected Peers

SNAT: Mode PRIMARY
    : State READY
    : Local Address 172.16.15.50
    : Local NAT id 1
    : Peer Address 172.16.15.62
    : Peer NAT id 1
    : Mapping List 1
    : InMsgs 5, OutMsgs 0, tcb 0x6609A500, listener 0x0

R3#sh ip snat distributed verbose

Stateful NAT Connected Peers

SNAT: Mode BACKUP
    : State READY
    : Local Address 172.16.15.62
    : Local NAT id 1
    : Peer Address 172.16.15.50
    : Peer NAT id 1
    : Mapping List 1
    : InMsgs 53, OutMsgs 0, tcb 0x66138B04, listener 0x66118088

[Georg Pauwen]

Hello,

post the full configs of all three routers. SNAT with primary and backup is rather outdated as far as I recall, which IOS are you running ? 

[paul driver]

Hello

I don’t see any nat redundancy name - Is your snat relating to any hrsp peering ?

Also be aware after a certain iOS train snat isnt even support it is superseeded by B2B nat - here  - I found this out the hard way when upgrading some 3900 rtrs not so long ago!

Anyway can you test again with the following config

Both rtrs

Int  x/x

description hrsp interface  

standby x name SNAT

exit

Rtr1

ip nat Stateful id 1

redundancy SNAT

mapping-id 12

protocol   udp

exit

Rtr2

ip nat Stateful id 2

redundancy SNAT

mapping-id 12

protocol   udp

exit