# problem with router MAC's reported by mrtg

## dmpogo

Yesterday I have set up mrtg-2.16.4-r1  to track my router network usage,  and generated config file with

```

cfgmaker --global "WorkDir: /var/lib/mrtg" --global "Options[_]: growright,bits" --ifref=ip 192.168.1.254 > /etc/mrtg.conf

```

to obtain, in particular, 

```

 ### Interface 6 >> Descr: '' | Name: '' | Ip: '' | Eth: 'e8-be-81-f6-c3-57' ###

### The following interface is commented out because:

### * --ifref=ip is not unique for this interface

# 

# Target[192.168.1.254_6]: 6:public@192.168.1.254:

........

```

Today I wanted to play with eth selection and run

```

cfgmaker --global "WorkDir: /var/lib/mrtg" --global "Options[_]: growright,bits" --ifref=eth 192.168.1.254   | less

```

I have obtained

```

### Interface 6 >> Descr: '' | Name: '' | Ip: '' | Eth: '30-78-65-38-62-65-38-31-66-36-63-33-35-37' ###

Target[192.168.1.254_30-78-65-38-62-65-38-31-66-36-63-33-35-37]: !30-78-65-38-62-65-38-31-66-36-63-33-35-37:public@192.168.1.254:

```

Since then for the sake of me I cannot get the correct MAC addresses.   Even when I return back to selection by IP

```

cfgmaker --global "WorkDir: /var/lib/mrtg" --global "Options[_]: growright,bits" --ifref=ip 192.168.1.254 | less

```

I get

```

### Interface 6 >> Descr: '' | Name: '' | Ip: '' | Eth: '30-78-65-38-62-65-38-31-66-36-63-33-35-37' ###

```

I have rebooted my router to no help. What's going on ?

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## anxt

Could it be that the router is returning the wrong value?  

Perhabs you can snmpwalk the router with something like

```

snmpwalk -v 2c -c public 192.168.1.254

```

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## dmpogo

 *anxt wrote:*   

> Could it be that the router is returning the wrong value?  
> 
> Perhabs you can snmpwalk the router with something like
> 
> ```
> ...

 

Thanks for the hint.    version 2 does not work for my router,  I did   snmpwalk - v 1 -c public 192.168.1.254,  and all MAC's seem OK

 *Quote:*   

> 
> 
> IF-MIB::ifPhysAddress.1 = STRING: e8:be:81:f6:c3:55
> 
> IF-MIB::ifPhysAddress.2 = STRING: 
> ...

 

----------

