Yeah, I have to retract on this one...I answered too quickly and not thoroughly.
When a request comes from the phone to DNS, DNS returns the next address in its list of Host A records for the FQDN. If that host does not respond to the phones provisioning request, the phone will ask again and get the next address in the list.
So, DNS just serves up IP addresses in round-robin fashion to each request that comes in. The phone has to know to request again instead of just failing and stopping there.
Which the supported phones do.
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George Ganahl CCXP, GCP
Principal Technology Consultant
Genesys
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Original Message:
Sent: 07-12-2019 03:25
From: Valery CHHOA
Subject: [SIP Phone provisionning] What happen if a one of the Edge is offline
Hello George,
Thanks for this answer. That's what I explain to the customer but got challenged since the Network It admin replied that the DNS won't know if one of the server is down. It's only job is to reply the IPs in a round robin way for each FQDN request. It won't ping the IP to check it's alive or not.
And since I'm no expert on DNS or DHCP, I couldn't argue with him ...
Envoyé de mon iPhone
Original Message------
Option 160 points to the FQDN, so DNS figures out which IP address is actually responding and will supply that IP address to the phone to use for the provisioning. All part of DNS functionality.
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George Ganahl CCXP, GCP
Principal Technology Consultant
Genesys
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