BLOCKING URL'S AND INSTANT MESSENGER IN ASA Example
nameif outside
security-level 0
ip address 192.168.137.2 255.255.255.0
no shut
!
interface Ethernet0/1
nameif inside
security-level 100
ip address 192.168.1.1 255.255.255.0
no shut
global (outside) 1 interface
nat (inside) 1 0.0.0.0 0.0.0.0
route outside 0.0.0.0 0.0.0.0 192.168.137.1
URLs to be
block with domain name like facebook
regex url1 "facebook.com"
regex url2 "myspace.com"
regex url4 "twitter.com"
regex url2 "myspace.com"
regex url4 "twitter.com"
Create Class
map by name urleg in order to match the domain names to be blocked
class-map type regex match-any urlreg
match regex url1
match regex url2
match regex url4
Inspecting http
traffic by the name http_url_policy
class-map type inspect http match-all http_url_policy
match request header host regex class urlreg
Inspecting IM
traffic by the name im-traffic
class-map type inspect im match-all im-traffic
match protocol msn-im yahoo-im
Create ACL of the interesting traffic for http
access-list http
permit tcp any any eq 80
Create ACL of the interesting traffic for IM
access-list 101 line 1 extended
deny ip 192.168.1.0 255.255.255.0 any
access-list 101 extended permit
ip any any
Create a class by the name http-inspection to capture
http interesting traffic and assign access-list i.e http
class-map http-inspection
match access-list http
match access-list http
Create a class by the name im_inspection to capture IM interesting traffic and
assign access-list i.e 101
class-map im_inspection
match access-list 101
Create Http inspection policy by the name http_policy
and map class-map i.e http_url_policy
policy-map type inspect http http_policy
parameters
class http_url_policy
drop-connection
parameters
class http_url_policy
drop-connection
Create IM inspection policy by the name im_policy and
map class-map ie im-traffic
policy-map type inspect im im-policy
parameters class im-traffic
drop-connection log
Create
policy-map by the name block-url-im and Map the inspection policy-map to the
class
policy-map block-url-im
class http-inspection
inspect http http_policyclass http-inspection
class im_inspection
inspect im im-policy
service-policy block-url-im
interface outside
