JUNOS forwards IPv6 link-local packets

Phil Bedard bedard.phil at gmail.com
Mon Apr 30 16:41:29 CDT 2012

On 4/30/12 2:36 PM, "Justin M. Streiner" <streiner at cluebyfour.org> wrote:

>On Fri, 27 Apr 2012, Chris Adams wrote:
>> I don't think that will work, because there's an automatic direct route
>> for fe80::/64 to all interfaces with family inet6 configured.  The only
>> way I see around it is to apply a firewall filter to all IPv6 interfaces
>> that blocks anything with a source in fe80::/64 and destination _not_ in
>> fe80::/64.
>I've verified this between two M7is in my lab, running Junos 10.3.  I
>tried to verify similar behavior between a 6509 running 12.2(33)SXJ2 and
>my target M7i, but either the Cisco box doesn't appear to allow the
>traffic, or the command parser in that version of IOS is smart enough
>not to allow a ping sourced from a link-local address, but destined to a
>non-link-local address.

When I tried this on IOS-XR I first tried a local ping and it did not
allow a ping sourced from a link-local address to ping any global address
except for one assigned to the same interface.  However that didn't stop
it from forwarding frames coming into an interface from another device.


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