tailieunhanh - The Complete IS-IS Routing Protocol- Part 8

The Complete IS-IS Routing Protocol- P8: IS-IS has always been my favourite Interior Gateway Protocol. Its elegant simplicity, its well-structured data formats, its flexibility and easy extensibility are all appealing – IS-IS epitomizes link-state routing. Whether for this reason or others, IS-IS is the IGP of choice in some of the world’s largest networks. | Juniper Networks JUNOS CLI 57 Logging into the System and Authentication When you first log into a router running JUNOS the first difference you see from IOS is that the system prompts you in a UNIX fashion for a username and a password 20 45 hannes@unixbox telnet frankfurt Trying . Connected to frankfurt. Escape character is A . Frankfurt ttypO login hannes Password --- JUNOS built 2002-06-03 18 59 57 UTC hannes@Frankfurt This is because the underlying base OS for JUNOS is a heavily modified FreeBSD. FreeBSD is a free UNIX clone just like the more popular Linux UNIX. Your can get further information about FreeBSD at http . But make no mistake JUNOS and the original FreeBSD are different OSs and large parts of the networking-related kernel routines have been changed. FreeBSD is targeted for a host operating system environment much like a networked PC. Typically host operating systems have A single routing table 1-3 network interfaces Tens of routes to handle An operating system targeted for both edge and core routing functions has to handle many more of each. Specifically these needs are Hundreds of routing tables Thousands of interfaces 100 000s of routes However there are still lots of things that remained in JUNOS such as all the networking tools telnet SSH ping and traceroute utilities or as in the previous example the login procedure. Once you are logged in with your username you have a set of privileges that are associated with your username similar to IOS. You can display those privileges by issuing a show cli authorization command. hannes@Frankfurt show cli authorization Current user hannes class super-user Permissions admin -- Can view user accounts admin-control -- Can modify user accounts clear -- Can clear learned network information 58 3. Introduction to the IOS and JUNOS Command Line Interface configure control edit field floppy interface interface-control . security security-control -- Can enter .