Events And Alarms; Ip Control Protocol (Ipcp) - Enterasys Security Router X-PeditionTM User Manual

PPP Features
Table 8-2 Multi-Class MLPPP Negotiation (continued)
present
present
The class number is defaulted to five for both short and the long sequence numbers. That includes
four suspendable levels from 0 to 4 with the highest level at 5. The current limits on memory and
throughput set the optimized number of class to 4 for the XSR.
The result of the number of suspendable classes after negotiation will set MLPPP to support up to
that level of classes both for transmission and receipt. The suspendable level could differ between
transmission and receipt depending on negotiation with the peer. For example, if the local peer is
defaulted at a level of five classes and the remote peer has a level of two classes, following
negotiation, the local peer could have two transmitting classes acknowledged by the remote peer
and five receiving classes acknowledged by the remote peer.

Events and Alarms

Multi-Class Option Negotiation
When Multi-Class is enabled on MLPPP, every member under the bundle uses the same value to
perform negotiation, and the member link under the bundle sets the negotiated value for Multi-
Class, such as header format and suspendable level. The remainder of the member link must have
same negotiated values, otherwise it will be rejected from joining the same bundle.
Multi-Class Receiving Packet
When a MLPPP packet is received with the class number outside the negotiated suspendable
levels, as:
• A class number larger than the negotiated suspendable level,
• A non-zero class number is present when the non Multi-Class option is negotiated,
The packet is silently discarded and the discard count for the bundle statistics increased. Also, the
following PPP debug message is generated:
MLPPP: Invalid Class Num

IP Control Protocol (IPCP)

IPCP negotiates the following options, as referenced in RFC-1332:
• The IP address of the system
• The compression protocol to be applied on IP datagrams (Van Jacobson Compressed TCP/IP)
Along with the above support, the following IPCP extension is also offered:
• Primary and Secondary DNS and NBNS address
Once negotiation is successful, IPCP allows IP traffic over the established PPP link. The negotiated
IP addresses and MTU of the interface are passed on to the higher layer (IP) to update its tables.
8-8 Configuring PPP
Option Type
nil present/Code = 6
present present
MLPPP with Short Sequence # & Multi-Class
Not valid