T.6 Protection against IP address spoofing in GGSN

33.2033G Security3GPPAccess security for IP-based servicesTS

All GGSNs that offer connection to IMS shall implement measures to prevent source IP address spoofing. Specifically, a UE attached to the GGSN shall not be able to successfully transmit an IP packet with a source IP address (or the prefix in the case of IPv6 stateless autoconfiguration) that is different to the one assigned by the GGSN during PDP context activation. If IP address spoofing is detected the GGSN shall drop the packet. It shall be possible for the GGSN to log the event in its security log against the subscriber information (IMSI/MSISDN), e.g. based on operator configuration.