Re: [OPSEC] [v6ops] WGLC for draft-ietf-opsec-v6

[[e-mail]]

Fernando,

>>>> The ping pong attack is mitigated in RFC4443.
>>> 
>>> I must be missing something.. what does RFC4443 have to do with this? A
>>> ping pong attack does not require the attack packets to be ICMPv6 echo
>>> requests...
>> 
>> https://tools.ietf.org/html/rfc4443#section-3.1
>>  One specific case in which a Destination Unreachable message is sent
>>  with a code 3 is in response to a packet received by a router from a
>>  point-to-point link, destined to an address within a subnet assigned
>>  to that same link (other than one of the receiving router's own
>>  addresses).  In such a case, the packet MUST NOT be forwarded back
>>  onto the arrival link.
>> 
>> Most implementations I'm aware of now implement this.
> 
> Why wouldn't an attacker send *any* packet meant for the p2p link, but
> that not correspond to the address of any of the two endpoints?
> 
> i.e., I don't see the need to focus on a specific kind of packet... I
> guess I'm missing something?

Yes, you are missing something.
RFC4443 specifies what behaviour should be if a router receives a packet on a point to point link that would end up being forwarded back out the same link. The specified behaviour is drop and send destination unreachable.
That solves the problem for any packet obviously. And any prefix length assigned to the link.

Cheers,
Ole