Yes, on MikroTik devices, you can modify the Time to Live (TTL) of the IP packets that pass through the router.

The TTL is a field in the IP header that limits the number of routers (hops) a packet can pass through before being discarded. Modifying the TTL can be useful in several scenarios, such as controlling packet propagation or in certain VPN or NAT configurations.

MikroTik RouterOS allows adjusting the TTL using mangrove rules in the firewall.

Here is a general guide on how to modify the TTL on a MikroTik device using mangle rules:

Step 1: Access Winbox or the Web Interface

First, log in to your MikroTik device using Winbox or the web interface (WebFig).

Step 2: Open the Firewall

From the main menu, navigate to IP > Firewall and select the tab Mangle.

Step 3: Create a New Mangle Rule

Click on the + to add a new mangrove rule. Here you will configure the criteria for the packages you want to modify.

Step 4: Configure the Mangle Rule

• chain: Choose prerouting to modify incoming packets or postrouting for outgoing packages, depending on your need.
• Mr. Address/Dst. Address: Optionally, specify source or destination addresses if you want to limit the rule to certain packets.
• Action: Choose change TTL.
• New TTL: Sets the desired TTL value. You can increase, decrease or set a fixed value for the TTL.
• Comment: Add a comment to your rule to remember its purpose.

Step 5: Apply and Verify

Click on Apply and then OK to keep the rule. It is good practice to verify that the rule is working as expected using tools such as traceroute or by examining the logs, if necessary.

Important notes

• Careful use: Changing the TTL of packets can have implications for how packets are handled on your network and on external networks. Use it with knowledge of the possible consequences.
• Compatibility: Make sure the version of RouterOS supports the actions you want to perform.

Modifying the TTL can be a powerful tool in network administration, but it must be used with an understanding of its effects on network traffic.

Mangrove rules offer significant flexibility for handling IP packets on MikroTik routers, allowing fine adjustments to how these packets are processed and routed.