[j-nsp] SSG5 Dual WAN failover functionality

[Jason Lixfeld]

I'm pretty new to Juniper, so please forgive any blatant missteps in  
terminology.

I've got a requirement to build three sites using SSG5s.  The three  
sites will all have dual WAN - PPPoE DSL and DHCP cable.  We will be  
using provider space for the dual WANs, so we won't be using our own  
IP space, BGP or anything of the like; only static routing to 0/0 to  
one of the two WANs.

The three sites will be meshed with LAN to LAN IPSec tunnels.  I  
understand I'll need to build two meshes on each device; one for each  
WAN circuit because they will both have two different WAN IPs.

Can the SSG5 intelligently sense that a WAN link is broken and  
failover to the other?  In the DSL and Cable worlds, rarely is an  
outage caused by a hard link failure, rather something in between  
causing traffic to stop.  Can the SSG5 detect outages such as this and  
make a decision to fail over?  Can it also make the same determination  
in order to fail back once the primary WAN link has been restored?  If  
I have two IPSec meshes, can SSG's do any sort of IPSec WAN tracking  
so the only one mesh is up at at time?