[j-nsp] AS_PATH regular expression question.

[Vladimir S. Blazhkun]

True or False: The regular expression of: 64512 .+ matches an AS path of
64521 64567 65000?

Theory ( JNCIS study guide by Joseph M. Soricelli ) says: false.

Practice ( my Juniper M5 based network ) says: true.

test at lab> show route aspath-regex "64512 .+" terse
Restart Complete
+ = Active Route, - = Last Active, * = Both

A Destination        P Prf   Metric 1   Metric 2  Next hop        AS path
   3.0.0.0/8          B 170        100        210 >10.186.0.125   64512 702 703 80 I
   6.5.0.0/19         B 170        100        210 >10.186.0.125   64512 702 702 702 702 I

As you see it matches AS_PATH "64512 702 703 80", and not only "64512 702 702 702 702".

What is the right answer you think?

-- 
Vladimir S. Blazhkun,
Lead IP NCC Specialist, JNCIA #773, OOO "PCS-Moscow",
Work phone: +7 095 7847617.