[j-nsp] Basic doubt on unit

[Kevin Oberman]

> Date: Mon, 25 Jan 2010 23:03:58 +0530
> From: Taqdir Singh <singh.taqdir at gmail.com>
> Sender: juniper-nsp-bounces at puck.nether.net
> 
> Hi All,
> 
>  I am new to juniper.l could you please share  why junos is made such like
> we must define unit (subinterface) for any configuration like ip etc ?

Because Juniper is a modern router OS and does not carry the legacy
assumptions that some types of interface must be either simple P2P or
p2MP connections. IOS dates from before the concepts that make
sub-interfaces generally available all interfaces and as a result makes
them a "special case" in a horribly convoluted configuration language.

JUNOS was designed to be consistent as possible in all cases (and it
still comes fairly close) so that the syntax can be more readily parsed,
both by JUNOS, itself, and by external tools (and people). Internally,
the configuration is really in XML, so the first things JUNOS does with
new configuration is to convert it to XML..
-- 
R. Kevin Oberman, Network Engineer
Energy Sciences Network (ESnet)
Ernest O. Lawrence Berkeley National Laboratory (Berkeley Lab)
E-mail: oberman at es.net			Phone: +1 510 486-8634
Key fingerprint:059B 2DDF 031C 9BA3 14A4  EADA 927D EBB3 987B 3751