# "Error, eth0: ARPOP_REPLY received from [ip/mac]"

## thewtex

Hi, 

I received the following error repeatedly during bootup

 *Quote:*   

> Error, eth0: ARPOP_REPLY received from [ip/mac]

 

This is on a machine with dhcpcd installed.

The ip address was another machine connected to the same switch.  Both machines are supposed to get their DHCP information from the router.  After shutting down the offending machine, the error ceased and everything booted correctly.

Please help me understand this error and what I should do to prevent it in the future.

Thanks,

thewtex

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## UberLord

Does it claim the other machine has the IP address? Also, try dhcpcd-3.1.9 as that's the latest.

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## thewtex

I haven't been able to get the problem to repeat.  

Thanks for the tip on dhcpcd-3.1.9 -- will try it out  :Smile: 

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## mimosinnet

I am getting the exact same problem. Why should this interface (A) claim the other interface IP (B)? In the previous boot both interfaces got the same IP. Nevertheless, I have now rebooted computer A and these are the results:

```
# ifconfig eth0

eth0      Link encap:Ethernet  HWaddr 00:A0:D1:CB:54:C2

          UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1

          RX packets:394 errors:0 dropped:0 overruns:0 frame:0

          TX packets:335 errors:0 dropped:0 overruns:0 carrier:0

          collisions:0 txqueuelen:1000

          RX bytes:76218 (74.4 Kb)  TX bytes:91814 (89.6 Kb)

          Interrupt:17 Base address:0xdead

NinLug joanet # dhcpcd eth0

Error, eth0: ARPOP_REPLY received from 192.168.1.105 (00:a0:d1:cb:2f:38)

Error, eth0: ARPOP_REPLY received from 192.168.1.105 (00:a0:d1:cb:2f:38)
```

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## b1f30

I've built my laptop from a stage4, and I'm also getting the same results:

err, eth0 ARPOP_REPLY

Odd, that the error also gives the IP/MAC of the workstation the laptop stage4 was built from.

udev related maybe?

Any ideas?

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## UberLord

 *b1f30 wrote:*   

> Odd, that the error also gives the IP/MAC of the workstation the laptop stage4 was built from.

 

If working from a stage4, you should ensure that /var/lib/dhcpcd is empty on new hosts.

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## KWhat

Any solutions to this issue?

I seem to have created this problem by cloning gentoo virtual machine in vmware.  I can not run 2 copies of the clones at the same time.

Is there something with the ip address cache in dhcp ?  

Note i have 2 different mac addresses.

*** Updated:  I solved this by rm /var/lib/dhcpcd/* on one of the two machines.  Seems it was some type of cache issue.

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## b1f30

 *UberLord wrote:*   

>  *b1f30 wrote:*   Odd, that the error also gives the IP/MAC of the workstation the laptop stage4 was built from. 
> 
> If working from a stage4, you should ensure that /var/lib/dhcpcd is empty on new hosts.

 

SOLVED.

That did the trick. Thanks Uber.

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## LavaJoe

 *b1f30 wrote:*   

>  *UberLord wrote:*    *b1f30 wrote:*   Odd, that the error also gives the IP/MAC of the workstation the laptop stage4 was built from. 
> 
> If working from a stage4, you should ensure that /var/lib/dhcpcd is empty on new hosts. 
> 
> SOLVED.
> ...

 

I got this error on my laptop when tryng to connect to a wireless network in Germany (the last time I had connected from Linux was in the US; I connected using Windows on this machine in Germany just before rebooting into Linux).  I also got a different error after another reboot, but it still would not get me an IP.

Removing the files from /var/lib/dhcpcd did the trick for me as well, but this was *not* a cloned machine.  I am running dhcpcd-3.2.3.

-Joe

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## UberLord

You probably encountered a server that doesn't understand DUID stuff then.

You'll be please to know that with dhcpcd-4 it's turned off by default (unless the compat USE flag is enabled AND a duid file exists).

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## shabbychef

I'm getting this error on a newly installed gentoo box (amd64) from a stage 3. As suggested above, I deleted all files in /var/lib/dhcpcd yet I still get the error:

err, eth0: ARPOP_REPLY received from 192.168.1.64 (XX:XX:XX:XX:XX:XX)

or whatever.

here's where I think I may be screwing things up:

```
phone line <-> dsl modem <-> netgear router --- new gentoo box which cannot start up dhcpcd (ARPOP_REPLY)

                                         |

                                         |

                                      working gentoo box w/ IP 192.168.1.64
```

(sorry, no <pre> codes here. the diagram is supposed to show the two boxen attached to the router.)

I am guessing that somehow the new gentoo box is trying to communicate with the old box rather than dhcp via the router. or the dsl modem can only hand out one IP address?? ack.

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## mimosinnet

 *shabbychef wrote:*   

> I'm getting this error on a newly installed gentoo box (amd64) from a stage 3. As suggested above, I deleted all files in /var/lib/dhcpcd yet I still get the error:
> 
> err, eth0: ARPOP_REPLY received from 192.168.1.64 (XX:XX:XX:XX:XX:XX)

 

I had got this message when I cloned two machines and they were having the same IP and and files in /var/lib/dhcpcd. How does the "working gentoo box" receives the 192.168.1.64 IP address? (In other words, what is the /etc/conf.d/net of both boxes).

Cheers!

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## shabbychef

something odd indeed. when box1 is turned off, and box2 (new gentoo install) is turned on, I do not get this error. rather dhcpcd works fine.

then, when I turned on box1 (which has been fine for months), it get this same error ARPOP_REPLY.... It keeps displaying this error. If I then issue halt on box2,

dhcpcd succeeds on box1 and I get internet. So the problem for me is that I cannot have 2 boxen both using dhcpcd on the same router? I am guessing that

it is the dsl modem which hands out the IP address, and they both compete for it or something like that. FWIW, here are the /etc/conf.d/net files

box1:

```

config_eth0=( "dhcp" )

dhcpcd_eth0="-H -t 20"

#this part added by ntp?

postup(){

 grep -e '^server' /etc/ntp.conf > /etc/ntpd.conf ||\

        echo "servers pool.ntp.org" > /etc/ntpd.conf

 /etc/init.d/ntpd restart

 }

```

box2:

```

config_eth0=( "dhcp" )

dhcpcd_eth0="-H -t 5"

```

both are running dhcpcd 3.2.3 on amd64. I am guessing I should read the home router HOWTO first before posting any more...

----------

## UberLord

Is the IP address handed out by the router different for each box?

Is the MAC address different for each card?

Have you tried dhcpcd-4.0.0-beta5?

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## shabbychef

* no: both get 192.168.1.64 (ack?)

* I am not sure, but I am guessing that the MAC addresses are different: These two machines were previously connected to a router at work (box 2 had windows on it, tho), where they were assigned distinct IP addresses. So I am guessing they have different MAC addresses

* Was not aware 4.0.0 was out. Am emerge --sync now and will return.

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## UberLord

Then the error is correct - they can't use the same IP at the same time  :Smile: 

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## shabbychef

This is to say that the hardware is at fault? i.e. the router which hands out the same IP to multiple MAC cards it 

sees at the same time. Any hints on how to correct this short of a hammer?

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## UberLord

Heh, no  :Smile: 

dhcpcd-3.x creates a uses a DUID by default. This is used to create an IAID which is used in the ClientID of the DHCP message. The ClientID is supposed to be unique for each interface on the network. The DUID persists in /var/lib/dhcpcd and should not be copied between hosts. The chances are this is what has happened. So on each machine erase /var/lib/dhcpcd/* and restart dhcpcd. You should then get unique addresses and the ARP error will go away.

You can also use the -I '' flag to stop DUID from being used, like so in /etc/conf.d/net

```
dhcpcd_eth0="-I ''"
```

This behaviour has been stopped in dhcpcd-4 - we no longer use a DUID by default (unless the compat USE flag is enabled AND a duid file exists).

Of course, you could also have a buggy DHCP server  :Smile: 

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## shabbychef

hmm. well, both boxen are now running dhcpcd-4.0.0_beta5, and I have set 

/etc/conf.d/net to:

```
config_eth0=( "dhcp" )

dhcpcd_eth0="-H -t 20 -I ''"
```

Now both boxen get 192.168.1.64 IP address. When this happens, they both cannot access the internet (using ping, say).

now what? Is this a problem with my ISP? My dsl modem? my router setup?

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## UberLord

I would guess router.

To be sure, capture a tcpdump and email or post them somewhere. To make a capture do this on each machine

```
tcpdump -s 0 -w /tmp/dump1.cap -i eth0
```

Then run dhcpcd or restart the interface.

Then ctrl-C the tcpdump to finish. Rinse and repeat on the other box.

I'll analyse the two dumps and let you know  :Smile: 

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## lsegalla

Had the same problem, i solved using the following code in /etc/conf.d/net

```

config_eth0=( "dhcp" )

dhcpcd_eth0="-H -t 5"

```

Then:

```

/etc/init.d/net.eth0 stop

cd /var/lib/dhcpcd

mv *.* /tmp

/etc/init.d/net.eth0 start

```

I only get an error message after i started eth0 (but it seems that the pc is working)

```

Running dhcpcd ...

err, eth0: Failed to lookup hostname via DNS: Name or service not known

eth0 received address 192.168.1.178/24

```

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## UberLord

That's an old error from dhcpcd-3, which has been long fixed in dhcpcd-4.

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