[126730] in North American Network Operators' Group
Re: Junos Asymmetric Routing
daemon@ATHENA.MIT.EDU (Ken Gilmour)
Thu May 27 20:39:00 2010
In-Reply-To: <AANLkTim-wx9j_3JnDCeg_kaS9P1_NOBdE1fLvwwkMb6U@mail.gmail.com>
From: Ken Gilmour <ken.gilmour@gmail.com>
Date: Thu, 27 May 2010 18:38:11 -0600
To: Ricardo Tavares <curupas@gmail.com>
Cc: nanog@nanog.org
Errors-To: nanog-bounces+nanog.discuss=bloom-picayune.mit.edu@nanog.org
Wow, very fast responses, Thanks Larry Sheldon and Ricardo Tavares!
On 27 May 2010 18:07, Ricardo Tavares <curupas@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?
>
> So, this behavior will be correct if next-hop for 3.3.3.0/24 is not
> installed. Just for troubleshooting purpose install a static route
> like:
>
> set routing-options static route 3.3.3.0/24 next-hop
> <the-correct-gateway-address> (ISP2)
>
Yes sir, this works, but when you change the static route to point
0.0.0.0/0to the next hop on the virtual router for the particular
interface (ISP2) it
starts going over the interface for ISP1 again. I also set
qualified-next-hop for ISP2 in the main routing table to no avail.
> If this works fine then verify the route table, are you using BGP to
> receive such routing info? If you are not filtering the update maybe
> the sender is. Verify the received routes using the "show route
> protocol bgp receive-protocol bgp x.x.x.x" (x.x.x.x is the bgp
> neighbor)
>
Yes sir, I have also gone to the extent of deactivating BGP and using only
static routes.
Thanks for your help!
Regards,
Ken
