1. The ONT *must* assign a public IP via DHCP.
2. The static public IP block is then routed through this DHCP public IP.
Generally, when an AT&T modem/gateway is being used, it would first get its DHCP public IP, then the customer would enter his purchased /29 block into the modem as "public subnet". Then he can enter one of these purchased static IPs on a router connected to the modem. When this is done, any outgoing WAN traffic will show the static public IP, not the DHCP public IP (even though it is routed through the DHCP IP).
Now I have bypassed the AT&T modem/gateway, and instead have two blocks of IPs assigned on the same interface in RouterOS. One block is obtained via a DHCP client on the interface (this would be the DHCP public IP), the purchased static /29 is manually entered under IP -> addresses.
The connection is live. Both the DHCP public IP and static public IPs are reachable from the internet. However, outgoing WAN traffic always uses the DHCP public IP as the source IP.
Below is the default routing table generated by RouterOS ,using mock IPs. 11.11.100.101 is the DHCP public IP, with gateway 11.11.100.1, whereas 22.22.100.156 is the static public IP, with gateway 22.22.100.158.
Code: Select all
Dst. Address Gateway Distance Routing Mark Pref.Source
0.0.0.0/0 11.11.100.1 reachable wan 1
11.11.100.0/22 wan reachable 0 11.11.100.101
22.22.100.152/29 wan reachable 0 22.22.100.156
Please note that 22.22.100.152/29 does depend on 11.11.100.0/22 being live to be "reachable".
So my question is, how do I adjust the routing table such that my wan uses 22.22.100.156 as outgoing IP instead of 11.11.100.101?
Your help would be greatly appreciated.