RE: [MBONED] multiple SSM sources behind a NAT

> -----Original Message-----
> From: Dan Wing [mailto:[email protected]] 
 
> During some offline discussions, Prashant Jhingran brought up an issue
> we aren't sure how to best resolve.
> 
> The problem is that if two (or more) SSM sources are on the 'inside'
> of a NAT, they can choose the same multicast IP address (G).  This
> works fine on the 'inside' of the NAT -- they are distinguished
> because their SSM channel is unique because they have different
> source IP addresses (S).  However, if their traffic is NATted, they
> will share the same IP source address on the Internet, as in the
> following diagram:
> 
>                       +-----+
>     SSM source A -----+     |
>      192.168.1.1      | NAT +------------- Internet
>                       |     |192.0.2.1  
>     SSM source B -----+     |
>      192.168.1.2      +-----+
> 
> 
> There seems to be only one viable approach to address this problem:

My assumption was always that the only NAT readily usable for this
scenario would be a 1:1 NAT. In other words, a NAT, not a NAPT.

Bert