# Duplicate Address Detection



## Priyaamaresh (Jun 18, 2012)

Hi,

Am trying to detect any presence of duplicate IPv6 address in FreeBSD 7.4/i386. *W*hen I tried with 

```
# net.ipv6.conf.bce0.accept_ra
net.ipv6.conf.bce0.accept_ra: Command not found.
```
where bce0 is the interface.

Can *y*ou please explain me is there any possibility for duplicate address detection?


----------



## DutchDaemon (Jun 18, 2012)

You appear to be running a sysctl(8) OID as a command, which is not possible. I have no idea whether the OID you're trying to read actually exists, but it should be run with a command like [cmd=]sysctl net.ipv6.conf.bce0.accept_ra[/cmd]. If that doesn't result in anything, run commands like [cmd=]sysctl net.ipv6.conf.bce0[/cmd] or [cmd=]sysctl net.ipv6.conf[/cmd] to find out what alternatives you might have.


----------



## Priyaamaresh (Jun 18, 2012)

*Duplicate Address Detection.*

Hi,
   I tried with all commands that were mentioned but I received:

```
# sysctl net.ipv6.conf.bce0
sysctl: unknown oid 'net.ipv6.conf.bce0'
# sysctl net.ipv6.conf
sysctl: unknown oid 'net.ipv6.conf'
# sysctl net.ipv6.conf.bce0.accept_ra
sysctl: unknown oid 'net.ipv6.conf.bce0.accept_ra'
```

Says unknown OID, please explain me what does it mean to and suggest how to make duplicate IPv6 address possible.


----------



## DutchDaemon (Jun 18, 2012)

No idea about the second question. You can run [cmd=]sysctl -a | less[/cmd] and have a look through the output to see which OIDs are available. Maybe SirDice or other IPcv6 fanatics have an idea about the actual question


----------



## DutchDaemon (Jun 18, 2012)

P.S.: try [cmd=]sysctl net.inet6.ip6 | grep dad[/cmd] This seems to contain at least a net.inet6.ip6.dad_count. Though this gives me a value of '1' on a system that doesn't even do IPv6, so whether this is useful is up for debate.

More tips may be gleaned from http://www.google.com/search?q=freebsd+ipv6+duplicate+address


----------

