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ip nat log translations with NVI enabled

Sergey Lazarev
Level 1
Level 1

Hello everyone,

I faced with a strange problem. I'm trying to enable translations logging for NAT NVI, but it doesn't work at all.

The scheme is very simple: R1-R2-R3

Config R1:

interface FastEthernet0/0
 ip address 10.0.0.1 255.255.255.252

router ospf 1
 network 10.0.0.1 0.0.0.0 area 0

Config R2:

interface Loopback0
 ip address 1.1.1.1 255.255.255.255
 ip nat enable
!
interface FastEthernet0/0
 ip address 10.0.0.2 255.255.255.252
 ip nat enable

interface FastEthernet0/1
 ip address 10.0.0.5 255.255.255.252
 ip nat enable

router ospf 1
 network 10.0.0.2 0.0.0.0 area 0
 network 10.0.0.5 0.0.0.0 area 0

ip nat log translations syslog
ip nat pool 1 1.1.1.1 1.1.1.1 prefix-length 30
ip nat source list 110 pool 1 overload
!
access-list 110 permit icmp any any

Config R3:

interface FastEthernet0/0
 ip address 10.0.0.6 255.255.255.252

router ospf 1
 network 10.0.0.6 0.0.0.0 area 0

ip route 1.1.1.1 255.255.255.255 10.0.0.5

 

Ping from R1 to R3 is successful,  and on R2 I see translations

R2#sh ip nat nvi translations
Pro Source global      Source local       Destin  local      Destin  global
icmp 1.1.1.1:5         10.0.0.1:5         10.0.0.6:5         10.0.0.6:5


BUT! in logs appear such things:

%IPNAT-6-CREATED: icmp 0.0.0.0:0 0.0.0.0:0 0.0.0.0:0 0.0.0.0:0
%IPNAT-6-CREATED: icmp 0.0.0.0:0 0.0.0.0:0 0.0.0.0:0 0.0.0.0:0

 

And as a result I cannot see in history who exactly initiated a connection.

I tried different IOS images on different routers.

Current release is Cisco IOS Software, 7200 Software (C7200-ADVENTERPRISEK9-M), Version 15.2(4)M7

If I use ip nat inside/outside, then I see translations in syslog, but I have to use NAT NVI for different reasons.

Is it possible to make a router to show correct translations?

 

1 Reply 1

Sergey Lazarev
Level 1
Level 1

Any ideas?

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