Mikrotik Routers and "Persistent"/"Consistent" NAT

RouterOS General
1

Does Mikrotik RouterOS have a setting that turns on what Sonicwall calls “Consistent NAT”.

When I lookup Consistent NAT in relationship to Mikrotik Routers I get referred to “Load Balancing”.

Is there anything analogous to this in a Mikrotik? If so, what is it called and how does one set it?

We have been tasked to enable “Persistent”/“Consistent” NAT for a client using Verizon One Talk as their hosted VoIP solution.
The client has a Mikrotik RB750 with the latest RouterOS v6.42.3 and firmware v6.42.3 applied.

2

Sonicwall is referring to a 1 to 1 NAT & PAT, i.e.

/ip firewall nat
Add chain=dstnat action=dst-nat to-addresses=InternalIP dst-port=1234
 dst-address=StaticWanIp in-interface=WanInterface
 
 Add chain=srcnat action=src-nat to-addresses=StaticWanIp
 src-address=InternalIp src-port=1234

Order is important here, so make sure the above rules are placed above the standard src NAT / Masquerade rule

3

Thank-you for your responce.

This is how Sonicwall describes Consistent NAT.

https://www.sonicwall.com/en-us/support/knowledge-base/170505836533942

This is less secure because a single Destination (responce) Port is always pointing to internal LAN private IP Address.

4

CZFan

What you propose is for a single public IP Address to private IP Address Dst NAT. This would mean that we would need to apply a Dst NAT for each VoIP phone and have them either set with Static addresses or DHCP reservation. (Q: Can an Address List be assigned to a Dst NAT?).

Our problem is that they are using VoIP mobile phone Apps through their WiFi and the use of DHCP reservation is a bit more complicated or unfeasible.

What Sonicwall is creating a static Dst NAT (Public IP to Private IP Public port A to port A) on the fly and is only applied to the UDP protocol.

5

look into dstnat action=same, you can then specify a block of IP’s / ports