[FFmpeg-user] Resolve (was Re: key frame)

[Carl Zwanzig]

On 6/29/2024 7:00 PM, Mark Filipak wrote:
> Everything is down to what your router does. 
Which in the vast majority of small installations (e.g. homes) is _also_ 
working as a NAT device and performs some filtering and basic firewall 
functions. Or, at least I hope the device you have does, it's hard to 
get one that doesn't.

> The world knows you by the IP that your ISP has assigned.
Sure, call it 198.3.160.206/24 (outside interface).

Let's then assume that the inside interface of the firewall is 
192.168.12.1/24 and the systems A & B are on .11 and .12.

> The only way that A or B are not publicly 
> addressable is if you're not connected to the Internet. 
Not correct if they are using RFC1918 addresses when pretty much by 
definition they are not "publicly addressable". If you have a single 
system directly connected to the ISP (without NAT/etc), then yes, that 
system will get the 198 address and be publicly accessible, but that's 
only ONE system. The only way for A and B to both be publicly 
addressable is if the ISP gives each on a separate IP and if routes 
exist to them.

BTW, "publicly accessible" means that datagrams from anywhere outside 
can be routed to a specific system, not that the system can send 
datagrams outbound.


> 192.168.0.xxx does not route to the Internet. 
More correctly, the router does not have a _route_ for that network and 
even if it did, the next hop would black-hole the datagrams.

> Do those 4 statements fit together in your mind? If not, ask.
Looked like 3, but never mind that.


> ...this is networking 101...
Yes, please study it, you seem to be mistaken in how things work and 
general network engineering practice.

z!