Verifone P400 -goes offline constantly

workerchimpworkerchimp Member Posts: 24

My credit card terminal keeps freezing up and I have to unplug it constantly to reboot it which takes several minutes which is an eternity when you have a line of customers. Nobody seems to understand this product. I am supposed to have ports 443 and 4443 open (was anyone else told this during their installation? I wasn't and AT&T cannot get the job done either.) Is it necessary to have a private VPN for the credit card terminal, or is there a workaround getting those impossible ports open? Anyone else having issues with their terminal going offline or do you all have enough money to support an IT manager?


  • gregaricangregarican Member Posts: 997 
    edited October 2021

    The credit card terminals can reside on the private, internal LAN. As long as they grab the proper client IP, DNS server, gateway, etc. values from a DHCP server on the LAN then they should get out to the Internet just fine.

    If you are a smaller outfit then most likely your internal network devices go out an AT&T cable modem for Internet. And if the devices are connected (either via hardwired Ethernet or WiFi) to the cable modem then the cable modem should be automatically handing out all of the DHCP values.

    Most ISP's have firewalls in place where inbound access to your internal network is blocked. But that's for the Internet getting in. These credit card terminals are just needing to go from the internal network out. As long as no outbound blocking is taking place things should just work?

  • workerchimpworkerchimp Member Posts: 24

    Thanks for the insight. I was just checking the settings in the terminal using the key sequence of 04268 (status) and it does have an internal IP address right now. However, I noticed that the DNS1 field is set to the gateway's address of which is strange because I thought DNS is supposed to have single digits (DNS2 is blank)

    I was told to set the DNS at the iPad (POS) to and Should the terminal also reflect these values? If so, how is this changed?

  • gregaricangregarican Member Posts: 997 

    Your gateway likely acts as a DNS server, which means it probably just forwards DNS requests to a "real" public DNS server. Like the Google ones at and If your credit card terminals, your iPads, and your desktop computers are all on the same network --- usually this means if one can get out then they all can get out. Assuming they are all automatically assigned their client IP address, their DNS server addresses, their gateway address, etc. from the gateway.

    Working IT in a retail environment for over 21 years now, I can relate to the frustration in spending hours on the phone with the payment processor support folks. Where they are going through every single scripted question from square one. Long story short is if the credit card terminal works most of the time and freezes up periodically, assuming your Internet connection is consistent, that usually means bad hardware. Unless there's a terminal configuration update that the payment provider can push down to the device.

  • DGNewnanDGNewnan Member Posts: 7

    Setting up payment terminal to a static IP will also fix this.

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