NAT BGP on one router

RouterOS Forwarding Protocols
1

Hi - have some problem to routing.
Have BGP peer 90.189.107.149-90.189.107.150 on out interface.
Have srcnat on this interface too. Have default route 90.189.107.149
Have real ip 194.190.72.1. What need to do. All nat users need ip adress 194.190.72.1 not 90.189.107.150.

[Gunner@MikroTik] /ip firewall nat> print
Flags: X - disabled, I - invalid, D - dynamic
0 chain=srcnat action=masquerade src-address-list=!Real
out-interface=new bgp

[Gunner@MikroTik] /ip route> print
Flags: X - disabled, A - active, D - dynamic,
C - connect, S - static, r - rip, b - bgp, o - ospf, m - mme,
B - blackhole, U - unreachable, P - prohibit

DST-ADDRESS PREF-SRC GATEWAY DISTANCE

0 ADb 0.0.0.0/0 90.189.107.149 20
1 A S 10.0.5.0/24 10.50.0.2 1
2 A S 10.10.100.0/24 10.50.0.2 1
3 A S 10.10.128.0/24 10.50.0.2 1
4 A S 10.20.0.0/24 10.50.0.2 1
5 ADC 10.50.0.0/24 10.50.0.3 10.50.0.3 0
6 ADC 10.50.1.0/24 10.50.1.1 new bgp 0
7 A S 10.200.0.0/24 10.50.0.2 1
8 ADC 90.189.107.148/30 90.189.107.150 new bgp 0
9 A S 192.168.0.0/16 10.50.0.2 1

What i need to do ? Sorry for my bad english it not my first language.

2

I don’t see that IP address in your route list, but in general you’d just use srcnat as an action rather than masquerade, and specify a to-address.

3

[Gunner@MikroTik] /ip route> print
Flags: X - disabled, A - active, D - dynamic,
C - connect, S - static, r - rip, b - bgp, o - ospf, m - mme,
B - blackhole, U - unreachable, P - prohibit

DST-ADDRESS PREF-SRC GATEWAY DISTANCE

0 ADb 0.0.0.0/0 90.189.107.149 20
1 A S 10.0.5.0/24 10.50.0.2 1
2 A S 10.10.100.0/24 10.50.0.2 1
3 A S 10.10.128.0/24 10.50.0.2 1
4 A S 10.20.0.0/24 10.50.0.2 1
5 ADC 10.50.0.0/24 10.50.0.3 10.50.0.3 0
6 ADC 10.50.1.0/24 10.50.1.1 new bgp 0
7 A S 10.200.0.0/24 10.50.0.2 1
8 ADC 90.189.107.148/30 90.189.107.150 new bgp 0
9 A S 192.168.0.0/16 10.50.0.2 1
10 ADC 194.190.72.0/22 194.190.72.1 new bgp 0
11 ADC 194.190.72.2/32 10.0.0.1 0
12 ADC 194.190.72.3/32 10.0.0.1 0
13 ADC 194.190.72.5/32 10.0.0.1 0

[Gunner@MikroTik] /ip address> print
Flags: X - disabled, I - invalid, D - dynamic

ADDRESS NETWORK BROADCAST INTERFACE

0 10.50.0.3/24 10.50.0.0 10.50.0.255 10.50.0.3
1 10.50.1.1/24 10.50.1.0 10.50.1.255 new bgp
2 90.189.107.150/30 90.189.107.148 90.189.107.151 new bgp
3 D 10.0.0.1/32 194.190.72.2 0.0.0.0
4 D 10.0.0.1/32 194.190.72.5 0.0.0.0
5 D 10.0.0.1/32 194.190.72.100 0.0.0.0
6 D 10.0.0.1/32 194.190.72.3 0.0.0.0
7 194.190.72.1/22 194.190.72.0 194.190.75.255 new bgp
8 D 10.0.0.1/32 194.190.72.72 0.0.0.0
Sorry not full.

use srcnat as an action rather than masquerade ? More detail please.

4

Read the wiki entry on NAT. To source NAT you have several options for actions. masquerade ‘magically’ picks an IP address on the interface the traffic is leaving through, so it picks the only IP you have configured on the interface. srcnat lets you specify what IP address to replace the source address with. Since 194.190.72.1 is known by your ISP to be reachable via 90.189.107.150 that’s a legitimate address to srcnat to, and return traffic will come back into the router and the srcnat will be undone.
http://wiki.mikrotik.com/wiki/Manual:IP/Firewall/NAT#Properties

5

new bgp is interface the traffic is leaving through. Have 2 ip 90.189.107.105 and 194.190.72.1. How i can say masquerade to pick 194.190.72.1 ?

6

ops sorry im just wake up.
In my case rule is.
[Gunner@MikroTik] /ip firewall nat> print
Flags: X - disabled, I - invalid, D - dynamic
0 chain=srcnat action=src-nat to-addresses=194.190.72.1