> Source: [sk170392](https://support.checkpoint.com/results/sk/sk170392)

# sk170392 - Proxy ARP advertises incorrect MAC addresses in Maestro environments

| Property | Value |
|----------|-------|
| Solution ID | sk170392 |
| Date Created | 2020-11-12 |
| Last Modified | 2020-11-16 |
| Technical Level | Advanced |
| Products | Scalable Platforms |
| Versions | R82.10, R82, R81.20 |
| OS | Gaia |

## Symptoms

- Proxy ARP advertises incorrect MAC addresses in Maestro environments.   
**Notes** :

* The IP of the Management interface is configured with an IP address that ends with `254`.
* The output of `[Expert@admin]# cat /etc/smodb.json | grep mac_magic` returns the value `254`.

<br />

## Cause

The MAC addresses, interfaces, and proxy ARP entries derive from the value of the `mac_magic` value. This value is set according to the last octet of the IP address of the Management interface.  

An algorithm that is fed the value `254 `from the `mac_magic` to calculate the MAC addresses functions differently than it does when the value is not `254`. This results in an incorrect calculation of the MAC addresses for the pseudo-interfaces used.

<br />

## Solution

This solution requires authentication. Please log in to view the full solution.

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