I maintain a private communications system and am not an expert in networking. I hope to describe an intermittent problem that I am seeing and have the experts determine if it could be a network issue.
In the communication system, there is a device that serves as a hot standby. The ethernet cable of this device runs through an A/B switch that opens or closes the connection to an ethernet switch when necessary. The hot standby device is typically activated once a week as a test but can be turned on at any given time. The device communicates with a server and they exchange three messages which registers the device in the server. Intermittently, the device will not register when activated. However the problem appears to be corrected by pinging the device.
A crude diagram is as follows:
Server0 <---> Switch0 <---> Router0 <---> T1 <---> Router2 <---> Switch 2 <---> A/B Switch2 <---> Device2
The basic registration messages that are exchanged are:
Device2 to Server0 - Boot message "Device2 is at this IP address"
Server0 to Device2 - Config message "OK Device2, here is your configuration"
Device2 to Server0 - Ack message "I acknowledge the configuration"
REGISTERED
Switch2 logs show what I believe to be appropriate: Interface12 up, line protocol for port 12 up
My questions begin with:
Since it may be a period of several days between activating Device2, is something cached in a table that would make either the Boot message or Config message not deliverable after a period of time?
Why does a ping seem to solve the problem?
