We have an HP procurve network and about 20 of the standard debit/credit pinpad terminals everyone is used to seeing at just about every store these days. They connect directly to the LAN and only communicate out to a payment site on SSL/443. No software or server in the middle.
The problem is that the devices usually give a TCP connection failure on the first attempted use. They'll then work fine for an hour straight. But, if allowed to sit idle for 10 - 15 mins (approx), they'll throw the initial error once.
Initially, they were all from a single company and we figured it had something to do with their setup, or the make/model. But recently, we've installed some new devices from a completely different vendor, using different types of pinpads ... and they have the same error.
We've tried static vs. DHCP IP addressing. We've added the outside payment site to a special firewall rule that allows them to exit without the normal threat checks. We've tried them on various Vlans. We've tried conencting them to various types of areas switches. Have even tried a scheduled batch file that pings them (home made stay-alive), every 3 mins. Nothing makes any difference. In terms of network problems, the devices are all conencted to the exact same vlans and areas switches as their nearby cash computers/printers - and we have no problems with anything else. The cash systems run full client/server/database apps and if the same disconenct issue was present for them because the networking in the area was bad, we'd hear about it fast.
Latest theory I'm about to tackle is related to arp cache timeouts, but I'm just getting started.
Would appreciate some assistance ... crazy ideas also welcome.