# ipv6 ping issue

## Mgiese

hi there,

from my gentoo box i can not ping my router nor other devices that use ipv6. 

but the gentoo box obtains a ipv6 adress and is pingable from other devices. i have no firewall installed,i`d say it`s a kernel related issue 

but i want to have a second opinion before building a new kernel

thanks a lot

btw : 

```
$ ping fe80::xxxx:xxxx:xxxx:xxxx

ping: unknown host fe80::xxxx:xxxx:xxxx:xxxx
```

edit : i just noticed big differences in /etc/hosts(between my gentoo box and a linux running settopbox), i added :

```
127.0.0.1   localhost.localdomain      localhost

# The following lines are desirable for IPv6 capable hosts

::1     localhost ip6-localhost ip6-loopback

fe00::0 ip6-localnet

ff00::0 ip6-mcastprefix

ff02::1 ip6-allnodes

ff02::2 ip6-allrouters
```

 but it did not help ...

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## Roman_Gruber

Why not use a network sniffer to get to the root cause?

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## kurly

fe80 is a link-local address which is not routable outside your LAN.  Those addresses need to be scoped to a device; syntax varies, but appending %eth0 (or appropriate device) to the IP should work with ping6.

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## Ant P.

kurly's answer is correct, but if typing %foo all the time is too much hassle you can also give your devices RFC4193 private IPs in fdxx::/56 (fd + 10 random hex digits), or just install avahi and nss-mdns to address them by name.

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## Mgiese

hi,

thanks for your suggestions. 

```
$ ping6 fe80::xxxx:xxxx:xxxx:xxx

connect: Invalid argument

```

 any ideas ?

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## NeddySeagoon

Mgiese,

```
ping6 fe80::2e0:4cff:fe69:1509 -I eth0
```

Link local IPv6 addresses are not routable, so you need to give an interface that the packets are to be sent over.

Link local addresses are also self assigned, not allocated by your router.

If you have a real IPv6 address that can be used on the internet, it will start with a 2.

Then you need an IPv6 firewall somewhere too as there is no NAT to hide you from the big bad internet.

----------

