2801 with NAT - Can't get Netflix to work

[jmaurin12]

Hi!

Again, in my test lab at home, I'm trying to use 2801 with iOS 12.4 as my router. I have only one valid ip (ipv4) and i'm using NAT for my devices. All is working fine, except Netflix on my smart TV (on PC works fine!).

I read about redirect of port 80 and 443 for incomming connection, but that's not my case. First, i have a webserver running on my home and port 80 and 443 are redirected to this server (internal IP different from Smart TV). Second, I tried to redirect port 80 and 443 to my internal TV address; stil not working.

Before this, I had a simple Wireless router doing routing on my home and everything was working fine, including Netflix. Also, in my smart TV, I CAN access and brownse Netflix. Te problem is when I try to start streaming....they sai that is not possible to play, to check latter. If I switch to my old router (wireless TPLink router), everything start to work.

This is my router configuration. I have some port redirects to my server (22.2, 22.4), but none for my Smart TV (the same way that was working in my wireless router).

BTW: theres no security enabled in router.

[devils_advocate]

I don't see why you need any static NAT to watch Netflix as the stream is being initiated from inside the network.

Are any of the static nat entries in your config the TV itself?

It may be worth starting a stream from the TV and checking the NAT translations to see if you can work out what port its trying to use.

[jmaurin12]

No, theres no port redirection for my TV, only for my servers. Is there any way to track/debug nat in 2801? 

I'm trying to avoid re-install my old router and run wireshark to see what's going on.....but, i'll do this as my last try.

[devils_advocate]

You can do:

#show ip nat translations

You may be able to use the pipe and include just the private IP address of the TV:

#show ip nat translations | i 192.168.1.1

Start a stream and see if you can see what ports its trying to use.

You can also debug NAT if you want to.

Why don't you run a wireshark now?

The TV should be able to access the internet like every other host, using Netflix should not need port translations inbound or outbound. The TV will try to connect to one of Netflix's Public IP addresses and will then start a stream on a Port which I believe it 80 or 443.

[jmaurin12]

I agree with you, but just don't work :(

I'll try to see translations today.

[jmaurin12]

Well, I've made some tests.....could not test command that you said, but here's what i've tested:

1) Change MTU from 1492 to 1480 (my old router has 1480). Still not working

2) I've conected my old router as a main router and disconnected cisco. Opened TV and Netflix. Start streaming a serie. Stop streaming, but keep netflix opened. Disconnect old router and connect Cisco again, as main router (keeping both same IP, but only one 'on' at same time). Start streaming and works.

So, looks like my TV isn't reaching DNS for streaming netflix.....also, when I open "Samsung Apps", I can't see icons.....everything works, except load of 'icon' for applications. In the old router, this doesn't ocour, all is fine. I alread tried to change DNS on my TV to: my cisco router (has DNS server relay configured); my local DNS server; my ISP DNS server; google DNS server (8.8.8.8); In all cases, TV Network status report that everything is ok and TV CAN reach internet, but still the same problem with Samsung Apps and Netflix streaming. The strange thing is that netflix open, get titles, my account info, etc etc......just streaming doesn't work!

[devils_advocate · Accepted solution]

What if you change your DHCP scope to use 8.8.8.8 as the DNS server?

Either that or give your TV a static IP address and use 8.8.8.8 as the DNS server.

[jmaurin12]

Hummm.... I've clicked 'correct answer' by mistake :/  is there any way to undo this?

BTW, I've tried to manually enter DNS on my TV and set to 8.8.8.8, same problem. TV Can reach internet, open netflix, etc etc....just don't start streaming :(

[Jon Marshall]

From everything I have read you need to port forward 80 and 443 but then you say you tried that and in addition with your test of disconnecting old router and putting Cisco in it's place it carried on streaming so perhaps not.

Can you -

1) clear all NAT translations - "clear ip nat translations *"

2) do a "debug ip nat translations"

3) post results together with the output of "sh ip nat translations"

and also what is the IP address of your TV ?

Jon

[jmaurin12]

Simples doesn't work! Nothing on Smarthub looks to work! But this happens only on TV, nothing else. Is there any way to redirect all packets to an internal IP by default?

In my wireless router this is called "DMZ". Every packet that does not have specific port redirect, is sent to an internal specific IP (default). Is there any way to do this in iOS 12.4?