User's Manual

SPEEDLAN Installation and Operation User Guide
11-18 SNMP Monitoring
• Default TTL
The default value inserted into the Time-To-Live field of the IP header of datagrams
originated at this entity, whenever a TTL value is not supplied by the transport-layer
protocol.
• Datagrams received
The total number of IP datagrams received by the host.
• Header errors
The number of input datagrams discarded due to errors in their IP headers, including bad
checksum errors, version-number mismatch, other format errors, time-to-live exceeded,
errors discovered in processing their IP options, etc.
• Invalid destinations
The number of input datagrams discarded because the IP address in their IP header's
destination field was not a valid address for this entity to receive. This count includes invalid
addresses (i.e., 0.0.0.0) and addresses of unsupported classes (i.e., Class E). For entities
which are not IP gateways and therefore do not forward datagrams, this counter includes
datagrams discarded because the destination address was not a local address.
• Unknown protocols
The number of locally-addressed datagrams received successfully but discarded because of
an unknown or unsupported protocol.
• Input Discards
The number of input IP datagrams for which no problems were encountered to prevent their
continued processing, but which were discarded anyway (e.g., for lack of buffer space).
Note that this counter does not include any datagrams discarded while awaiting re-
assembly.
• Deliveries
The total number of input datagrams successfully delivered to IP user-protocols.
• Output requests
The total number of IP datagrams that are user-protocols (including ICMP) supplied to IP in-
requests for transmission. Note that this counter does not include any datagrams counted in
Datagrams forwarded.
• Output discards
The number of output IP datagrams for which no problem was encountered to prevent their
transmission to their destination, but which were discarded anyway (e.g., for lack of buffer
space). Note that this counter would include datagrams counted in Datagrams forwarded if
any such packets met this (discretionary) discard criterion.