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Multiple entries for Static NAT

Godwin_S
Level 1
Level 1

Hi,

I have a small doubt from below NAT translation output. I only do outside nating here. 

My Questions:

1) If all three sources initiate traffic to 172.16.91.130 at same time, can this static nat be translated for all three flows?

2) If only first source initiate traffic to 172.16.91.130, the nat will be translated and populated in nat table. Once this flow is terminated, considering the nat table still has entry due to timeout, if second source initiate traffic to 172.16.91.130, can the static translation be used again, regardless of the entry in nat table.

 

Just trying to understand how all 3 sources mapped to single nat entry in nat table.

 

 

 

Config:

ip nat outside source static 172.31.112.19 172.16.91.130

 

Output:

tcp 10.217.14.2:33285 10.217.14.2:33285 172.16.91.130:344 172.31.112.19:344
tcp 10.217.14.7:33262 10.217.14.7:33262 172.16.91.130:344 172.31.112.19:344
tcp 10.217.14.8:33346 10.217.14.8:33346 172.16.91.130:344 172.31.112.19:344

 

 

Thanks,

Godwin. S

1 Accepted Solution

Accepted Solutions

Hello

Nat will utilise a ephemeral (dynamic) port for each duplicate nat session, As your can see in your own translation post.

tcp 10.217.14.2:33285 10.217.14.2:33285 172.16.91.130:344 172.31.112.19:344
tcp 10.217.14.7:33262 10.217.14.7:33262 172.16.91.130:344 172.31.112.19:344
tcp 10.217.14.8:33346 10.217.14.8:33346 172.16.91.130:344 172.31.112.19:344

 

res

Paul


Please rate and mark as an accepted solution if you have found any of the information provided useful.
This then could assist others on these forums to find a valuable answer and broadens the community’s global network.

Kind Regards
Paul

View solution in original post

1 Reply 1

Hello

Nat will utilise a ephemeral (dynamic) port for each duplicate nat session, As your can see in your own translation post.

tcp 10.217.14.2:33285 10.217.14.2:33285 172.16.91.130:344 172.31.112.19:344
tcp 10.217.14.7:33262 10.217.14.7:33262 172.16.91.130:344 172.31.112.19:344
tcp 10.217.14.8:33346 10.217.14.8:33346 172.16.91.130:344 172.31.112.19:344

 

res

Paul


Please rate and mark as an accepted solution if you have found any of the information provided useful.
This then could assist others on these forums to find a valuable answer and broadens the community’s global network.

Kind Regards
Paul
Review Cisco Networking for a $25 gift card