rfc 1812 third party address on traceroute
Marc Storck
mstorck at voipgate.com
Wed Jun 1 21:50:28 UTC 2016
I'm not saying anyone is wrong here. I merely want to point out eventual incompatabilities.
So please don't get me wrong.
Regards,
Marc
> On 1 juin 2016, at 23:46, William Herrin <bill at herrin.us> wrote:
>
> On Wed, Jun 1, 2016 at 3:16 PM, Marc Storck <mstorck at voipgate.com> wrote:
>>> .-----------------.
>>> | |
>>> | B |--------- D
>>> S ---------| A R |
>>> | C |--------- (toward S)
>>> | |
>>> `-----------------'
>> With BCP38 in mind, could there be situations
>> where Router R is not allowed to source packets
>> with address A out of interface C?
>
> Hi Marc,
>
> I think you're right. Address A in a /30 from ISP A. ISP C accepts
> source addresses from your /24 but not the A /30. So if the router
> does not follow the RFC (sends an ICMP packet out C with a source
> address from A), typical asynchronous routing can result in
> black-holding the ICMP error message.
>
> You've hit on a good reason to follow the RFC by default instead of
> doing what Randy wants. ;)
>
> -Bill
>
>
>
>
> --
> William Herrin ................ herrin at dirtside.com bill at herrin.us
> Owner, Dirtside Systems ......... Web: <http://www.dirtside.com/>
More information about the NANOG
mailing list