This document describes how to troubleshoot IP source violation which are a frequent issue when Verizon is the carrier.

Problem:

Verizon assigns an IP address specifically to each client/SIM, and it expects to receive traffic sourced only from that IP.

Source violation occurs when Verizon detects that traffic sent from the client is sourced from a different IP than the one they previously assigned.

For example, if the IP address 6.6.7.8 was assigned, and Verizon receives traffic from the IP address 6.6.9.10, the issue is present or, if the traffic is hitting the Verizon Gateway without being translated, i.e. RFC1918 traffic hitting the Verizon gateway as is, will also violate the rule and the gateway will force disconnect the Gateway.

Every time Verizon receives over 10 packets from the device with a different IP address, the connection to the cellular network flaps and stops. As a result, a new connection is initiated from the cellular device, and it can get either the same IP address as before or a new one.

Solution/Configuration check required:

Please check if RFC1918 is not hitting the Verizon Gateway IP without being translated to the WAN interface source IP.

All traffic exiting the VOS must be set to use the assigned interface WAN IP either using the IP Verizon assigned as a DHCP server, or the statically assigned IP allocated by Verizon.