How to set static public IP for router 819 with a SIM card

[longtran51313]

Dear community,

I am trying to setup a public static IP for cisco router 819 with a SIM card. Could you help advise please? 

Thanks in advance

[Georg Pauwen]

Hello,

I am not sure what the options are under the cellular interface...does it support 'ip unnumbered'.

interface cellular 0

ip unnumbered Loopback0

!

interface Loopback0

ip address x.x.x.x y.y.y.y

[Giuseppe Larosa]

Hello @longtram51313,

mobile providers usually  do not provide fixed public IPv4 to their customers.

The main reason is that each mobile operator has so many users that overcome the number of public IP addresses they own.

So you may receive either a dynamic public IP address or a dynamic Private IP address (RFC 1918 10/8 and so on) but then in the internet the provider can use CGNAT Carrier Grade NAT to perform NAT.

If you need to be able to connect to your device over time you can use a dynamic DNS solution with your device registering at each session with a dynDNS server so that you can reach it pointing to its URL resolved by DNS.

We did so in one case and it worked

Hope to help

Giuseppe

Hope to help

Giuseppe