Syslog Protocol Definitions | Cisco 400-251 Exam | CCIE Security

Syslog Protocol Definitions

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Which two options represent definitions that are found in the syslog protocol (RFC 5426)? (Choose two.)



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A. B. C. D. E.


Syslog is a standard protocol used to send log messages and event notifications within a network. It uses the User Datagram Protocol (UDP) to send messages between network devices, such as routers, switches, firewalls, and servers. RFC 5426 defines the protocol for syslog message transport.

A. Syslog message transport is reliable. This option is incorrect because syslog message transport is not reliable. UDP, the protocol used by syslog, does not guarantee delivery or reliability. Messages can be lost or dropped in transit, and there is no acknowledgment of receipt or confirmation.

B. Each syslog datagram must contain only one message. This option is correct. RFC 5426 requires that each syslog datagram contains only one message. A message can span multiple datagrams, but each datagram should only contain one message. This requirement helps ensure the integrity and consistency of syslog messages.

C. IPv6 syslog receivers must be able to receive datagrams of up to 1180 bytes. This option is incorrect. RFC 5426 does not specify a maximum datagram size for syslog messages. However, it recommends that datagrams should not exceed the Maximum Transmission Unit (MTU) of the network to avoid fragmentation.

D. Syslog messages must be prioritized with an IP precedence of 7. This option is incorrect. Syslog messages do not use IP precedence as a priority mechanism. Instead, they use a facility and severity level to classify the messages based on their importance and urgency.

E. Syslog servers must use NTP for the accurate time stamping of message arrival. This option is incorrect. RFC 5426 recommends that syslog messages include a timestamp to indicate when the event occurred. However, it does not require syslog servers to use Network Time Protocol (NTP) for timestamping. The accuracy of the timestamp depends on the clock synchronization of the sender and receiver devices.