The Definitions of Managed Objects for the IP Network Control Protocol of the Point-to-Point Protocol
Extracted elements (17)
Objects were selected for the MIB by requiring they be essential for fault or configuration management, considering evidence of current use, limiting total object count, and excluding objects derivable from other MIBs. Objects solely for debugging implementations were explicitly excluded.
The PPP IP Group is separated into a status/statistics table (pppIpTable) and a configuration table (pppIpConfigTable) to facilitate placing configuration variables in a separate MIB view, enabling finer-grained access control.
The values of IPCP negotiation objects (compression protocol, max slot IDs) are undefined until IPCP negotiation completes and pppIpOperStatus reaches opened; the value returned before that point is implementation-dependent.
Implementation of the PPP IP Group is mandatory for all PPP implementations that support IP over PPP. All objects in the group must be implemented if the group's semantics are applicable.
pppIpConfigAdminStatus is a read-write INTEGER (open(1), close(2)) that injects administrative open or close events into the IPCP finite state machine when written.
pppIpConfigCompression is a read-write INTEGER (none(1), vj-tcp(2)) with default none(1) that controls whether the local node attempts to negotiate IP compression during IPCP; changes take effect when the link is next restarted. References RFC 1332 Section 4.0.
pppIpConfigTable (OID ppp.3.2) is a separate read-write configuration table for IPCP parameters per PPP link, indexed by ifIndex, designed to allow placement in a distinct MIB view for access control.
pppIpLocalMaxSlotId is an INTEGER(0..255) reporting the Max-Slot-Id parameter advertised by the local node for VJ-TCP header compression; value is 0 if VJ-TCP compression is not in use. Only meaningful when pppIpOperStatus is opened.
pppIpLocalToRemoteCompressionProtocol indicates the IP compression protocol the local PPP-IP entity uses when sending to the remote entity; values are none(1) or vj-tcp(2). Only meaningful when pppIpOperStatus is opened.
pppIpOperStatus is an INTEGER object (opened(1), not-opened(2)) indicating the operational status of the IP network protocol; a value of opened means the IPCP finite state machine has reached the Opened state.
pppIpRemoteMaxSlotId is an INTEGER(0..255) reporting the Max-Slot-Id parameter advertised by the remote node for VJ-TCP header compression; value is 0 if VJ-TCP compression is not in use. Only meaningful when pppIpOperStatus is opened.
pppIpRemoteToLocalCompressionProtocol indicates the IP compression protocol the remote PPP-IP entity uses when sending to the local entity; values are none(1) or vj-tcp(2). Only meaningful when pppIpOperStatus is opened.
pppIpTable (OID ppp.3.1) is a mandatory read-only table containing IP parameters and statistics for the local PPP entity, indexed by ifIndex.
All security-related variables are placed in separate MIB Tables to facilitate their identification and placement into protected SNMPv2 MIB View Subtrees, supporting the use of authentication and privacy protocols for access control.
Making security-risk variables READ-ONLY is not recommended because authentication protocol variables could still be easily read by unauthorized parties. Using SNMPv2 MIB views with authentication and privacy protocols is the preferred mitigation.
The PPP MIB allows operators to configure and control PPP links including authentication protocols, representing a security risk. To mitigate this, security-sensitive variables are placed in separate optional MIB Groups so implementors may elect not to implement them.
The IPCP finite state machine has at least two observable states: Opened and not-Opened. The pppIpOperStatus object reflects whether the FSM has reached the Opened state, which gates the validity of compression and slot-id negotiated parameters.