[Openswan Users] OpenSWAN load balancing setup

[Willie Gillespie]

To be honest... I don't know.  I'm not sure if Openswan just looks at 
the %defaultroute once, or if it is constantly monitoring it.

The default for leftnexthop is "%direct (meaning right)."  I imagine 
that the routing table takes effect like with any other connection. 
Since once a route is established, the kernel caches it -- it should 
continue to use that ISP.

If the IPsec connection is started from your Openswan box, I don't see 
much of an issue as long as the link it is using remains up.

Having never played with load balancing, I can see a slight problem. 
Imagine a connection made over ISP1.  Then they disconnect and reconnect 
over ISP2 (perhaps by using round-robin DNS).  I believe that the old 
route will still be cached on your box and go out ISP1 even if it came 
in through ISP2.

That's not really an Openswan problem, but a load balancing one.

I'd be curious to hear the results of any experiments you do, however.

Willie

plug bert wrote:
> Hello,
> 
> 
>     Please advise if the following setup will work; end goal is to distribute VPN traffic over the two ISPs, and possibly set up automatic failover.
> 
>     Say that the OpenSWAN box is configured as follows:
> 
>                                  +------------>(eth0) ISP1
>                                  |
> subnet1 <-->(eth2) OpenSWAN box--+
>                                  |
>                                  +------------>(eth1) ISP2
> 
> If i configure load balancing over the two links via iproute command
> 
> ip route add default scope global nexthop via $ISP1 dev eth0 weight 1 nexthop via $ISP2 dev eth1 weight 1 
> 
> 
> and set 
> 
> leftnexthop=%defaultroute
> 
> 
> will this do the job? tia
> 
> 
> 
> 
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