ISR 4331 Router Smart License Registratin Call-Home failed

[SaintEvn]

We've registered ISR 4331 Router with Smart Licensing .
We created smart token and put it in our Router but it failed and show the following error.

Registration: Status: REGISTERING - REGISTRATION IN PROGRESS Export-Controlled Functionality: NOT ALLOWED Initial Registration: FAILED on Aug 26 15:46:11 2020 Failure reason: Fail to send out Call Home HTTP message. 

 Our ISR 4331 router have internet connectivity.Can you guys please help me with this ? What should I do now ?
we cannot ping tools.cisco.com and also cannot telnet tools.cisco.com with 443.

[balaji.bandi]

First i will check are you able to resolve :

nslookup tools.cisco.com - is this works ?

try ip address https://x.x.x.x - see is that works ? also try https://tools.cisco.com - is this works ?

[SaintEvn]

Hi,
If it's was from Router CLi , no it can't be resolved.
If it was from the computer that connects to the router, it is resolved .
And I can't also ping tools.cisco.com from ISR first.But after I've added "ip host tools.cisco.com 173.37.145.8"
it can ping now.
I've also tried "telnet tools.cisco.com 443" but it is not work.

[balaji.bandi]

Looks like Device is not resolving the DNS entries.

before trying to register with smartlicense server, try from device

1. you able to ping tools.cisco.com

2. Make sure your  ACL allow Port 443 to connect cisco

3. try telnet tools.cisco.com 443 ( you need to allow in VTY lines use telnet)

below guide for reference :