The best source is the IPv4 standard RFC 791: "The Options provide for control functions needed or useful in some situations but unnecessary for the most common communications. The options include provisions for timestamps, security, and special routing....The options may appear or not in datagrams...The option field is variable in length. "
The following options exist (from my own TCP/IP course): +++++++++++++++++++++++++++++++++++++++++++++++++ o the security if the data field is encrypted, o the source routing (loose or strict) where the actual route followed by the datagram may be specified as a list of router addresses, o the route recording, where the addresses of the visited routers are recorded during the transit of the datagram through the internet path, o the time recording (timestamp) used by the visited routers to register the current time in the processed datagram. ++++++++++++++ For more details, codes etc. go to the RFC. As options are extremely rarely used I wonder whether some filtering upon them would be available on routers? Rita Aamer Kaleem wrote: > > Can anyone shed some light on "Options" in the IP Packet. On CCO, it is said > that they can used for security etc. Also how can we filter packets based on > "option types". > > Thanx, > > Aamer kaleem Message Posted at: http://www.groupstudy.com/form/read.php?f=7&i=31388&t=31364 -------------------------------------------------- FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
