Route old IP (from old, now non-existent subnet) to LAN IP

  • I'm trying to find a solution to "catch" traffic for a non-existent IP (on a subnet that doesn't exist anymore), to no avail.

    Here's our network:
    LAN ->

    Now, the router has no knowledge of subnet, but I want to "map" or "redirect" traffic addressed to to say

    I tried different things, VIP, 1:1 NAT, and searched a lot on this, can't figure it out. I'm thinking this should not be too complicated, I must be missing something …

    Reason for this is we had to change subnet, and we have a piece of software that had an IP hardcoded in it (and we don't have source code).

  • If it is traffic destined for the firewall, you should be able to add an alias IP and rules to allow it. Which interface does the traffic come in on, and where is the destination machine?

  • The network is really basic, all clients are on subnet. Right now nobody knows about the subnet. I guess I'll have to have a route for the subnet and have my router IP the default gateway for it.

    Traffic comes in the LAN interface (, destination machine is

  • Tricky. Traffic shouldn't really be traversing the firewall at all if I'm following you. (Both source and destination are on the LAN)
    Crazy idea- maybe put a VIP on the WAN for, forward all needed ports to, enable NAT reflection- proxy+NAT for all NAT rules.

Log in to reply