TABLE OF CONTENTS

• Question:
  • Case1: URL strings match
  • Case2: Regex pattern match
  • Case3: Complex regex pattern match
  • Pattern Test:

Question:

How to use url string and regex pattern match in URL filtering

Solution:

In Versa flexvnf, URL based traffic filtering can be done based on url string or pattern match.

To match based on url string, define the exact url. e.g. www.facebook.com.

Case1: URL strings match

Incases where url filtering is based on pattern,we need to use regex to match url string, e.g .*facebook.* 

(.*<string>.*) for url string www.facebook.com. 

IMP NOTE: We use standard regex pattern and it is recommended to defined strict pattern match, else it may cause similar url's strings to match defined patterns.

Case2: Regex pattern match

Case3: Complex regex pattern match (\w*\.)microsoftonline\.com(\/.*)" 

NOTE:- Tested on 21.2.3 

admin@SDWAN-Branch3-cli(config)% show orgs org-services Tenant1 url-filtering
user-defined-url-categories {
    URL_with_Blackslash {
        urls {
            patterns "(\w*\.)microsoftonline\.com(\/.*)" {
                reputation trustworthy;
            }
        }
    

Pattern Test:

Open public site as regexr.com or regextester.com can be used to validate the url string match to defined regex pattern.

Example 1: 

Defined pattern *.sex*  to match www.sex.com is also matching url string like search.com.

Making the pattern *.sex.*  match strict, avoids matching similar url string.

Example 2: 

Defined pattern .*kp.*  to match all north korean domain but its matching non korean domain url strings.

Correct pattern  .*(\.kp)($|\/.*) to match all and only north korean domains.