[afnog] PIX VPN & Backup Link Issues

[Bernard Wanyama]

Hi All,  
 
I have got a challenging scenario on my hands.  
 
Presently, I have a Cisco PIX doing an IPSec VPN with a remote 
business partner. 
The PIX is located on a /29 subnet provided by ISP A.  
 
I now need to bring in a backup link from a second ISP, ISP B to cover 
me in case the main link fails. 
 
Here is my ASCII network diagram  
 
212.x.x.x/30        193.x.x.x/29               192.168.x.x/24  
 
Primary   +--------+             +------+         +--------+ 
Link via  | Cisco  |             |Cisco |         |  LAN   | LAN PCs 
 ---------| 2620   |-------------|PIX   |---------| Switch |-------- 
ISP A     |        |             |      |         |        | 
          +---+----+             +------+         +--------+ 
              | 
              |Proposed 
              |Backup Link 
              |via ISP B 
              | 
          81.x.x.x/30  
 
 
The question is, what is the easiest way of ensuring that traffic to 
my /29 subnet is routed back in case the primary link is down and I've 
engaged the backup link via ISP B.  
 
Remember that the /29 was obtained from ISP A. I also do not want to 
run BGP just yet.  
 
 
TIA,  
 
--  
Bernard Wanyama 
Support Engineer 
Linux Solutions  
Kampala, UGANDA 
Cell: +256 71 193979