Junos Asymmetric Routing
Larry Sheldon
LarrySheldon at cox.net
Fri May 28 01:49:06 UTC 2010
On 5/27/2010 19:38, Ken Gilmour wrote:
> Wow, very fast responses, Thanks Larry Sheldon and Ricardo Tavares!
>
> On 27 May 2010 18:07, Ricardo Tavares <curupas at gmail.com> wrote:
>
>> Not sure if I correctly undestand you but default route its the route
>> that the packet must follow if it do not have a specific route for the
>> destination, so, if the next-hop for the source IP (3.3.3.3) is not in
>> the route table then the packet will follow the default route (ISP1).
>>
>
> Yes I believe that would be the default if the session was initiated on the
> inside, but if it comes from outside on a particular interface which is not
> the default route, why would the router then send the packet out another
> interface? Should the device not route session-based traffic according to
> where it originated?
I'm close to the edge of what I know (or remember--i've been inactive
for a while) but when a packet arrives on an interface, the routing
engine has to decide where to poke it bqased on what is in the
packet--there is no information as to where it came from, or to what it
is a response. If it isn't in the IP header, it isn't available for
routing decisions. ("Policy routing" can provide additional data, as
can source routing. But one requires a human being to provide the rule,
and the other requires somebody or something else outside the router to
calculate the route. I don't think anybody much allows source routing
anymore.)
--
Somebody should have said:
A democracy is two wolves and a lamb voting on what to have for dinner.
Freedom under a constitutional republic is a well armed lamb contesting
the vote.
Requiescas in pace o email
Ex turpi causa non oritur actio
Eppure si rinfresca
ICBM Targeting Information: http://tinyurl.com/4sqczs
http://tinyurl.com/7tp8ml
More information about the NANOG
mailing list