PIX/ASA 7.x and Later: Block the Peer-to-Peer (P2P) and Instant Messaging (IM) Traffic Using MPF Configuration Example

CiscoASA#show run
: Saved
:
ASA Version 7.1(1)
!
hostname CiscoASA
enable password 8Ry2YjIyt7RRXU24 encrypted
names
!


!--- Output Suppressed



http-map inbound_http
 content-length min 100 max 2000 action reset log
 content-type-verification match-req-rsp action reset log
 max-header-length request 100 action reset log
 max-uri-length 100 action reset log
 port-misuse p2p action drop
 port-misuse im action drop
 port-misuse default action allow


!--- The http-map "inbound_http" inspects the http traffic !--- as per various parameters such as content length, header length, !--- url-length as well as matches the P2P & IM traffic and drops them.


!


!--- Output Suppressed


!
class-map inspection_default
 match default-inspection-traffic
class-map http-port
 match port tcp eq www


!--- The class map "http-port" matches !--- the http traffic which uses the port 80.


!
!
policy-map global_policy
 class inspection_default
  inspect dns maximum-length 512
  inspect ftp
  inspect h323 h225
  inspect h323 ras
  inspect netbios
  inspect rsh
  inspect rtsp
  inspect skinny
  inspect esmtp
  inspect sqlnet
  inspect sunrpc
  inspect tftp
  inspect sip
  inspect xdmcp
policy-map inbound_policy
 class http-port
  inspect http inbound_http


!--- The policy map "inbound_policy" matches !--- the http traffic using the class map "http-port" !--- and drops the IM traffic as per http map !--- "inbound_http" inspection.


!
service-policy global_policy global
service-policy inbound_policy interface inside


!--- Apply the policy map "inbound_policy" !--- to the inside interface.


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CiscoASA#

CiscoASA#show running-config
: Saved
:
ASA Version 8.0(2)
!
hostname pixfirewall
enable password 8Ry2YjIyt7RRXU24 encrypted
names



!--- Output Suppressed


class-map inspection_default
 match default-inspection-traffic
class-map imblock
 match any


!--- The class map "imblock" matches !--- all kinds of traffic.


class-map P2P
 match port tcp eq www


!--- The class map "P2P" matches !--- http traffic.


!
policy-map type inspect dns preset_dns_map
 parameters
  message-length maximum 512

policy-map type inspect im impolicy
 parameters
 match protocol msn-im yahoo-im
  drop-connection



!--- The policy map "impolicy" drops the IM !--- traffic such as msn-im and yahoo-im .


policy-map type inspect http P2P_HTTP
 parameters
 match request uri regex _default_gator
  drop-connection log
 match request uri regex _default_x-kazaa-network
  drop-connection log


!--- The policy map "P2P_HTTP" drops the P2P !--- traffic that matches the some built-in reg exp's.



 
  

policy-map IM_P2P
 class imblock
  inspect im impolicy
 class P2P
  inspect http P2P_HTTP  



!--- The policy map "IM_P2P" drops the !--- IM traffic matched by the class map "imblock" as well as P2P traffic matched by class map "P2P".


policy-map global_policy
 class inspection_default
  inspect dns preset_dns_map
  inspect ftp
  inspect h323 h225
  inspect h323 ras
  inspect netbios
  inspect rsh
  inspect rtsp
  inspect skinny
  inspect esmtp
  inspect sqlnet
  inspect sunrpc
  inspect tftp
  inspect sip
  inspect xdmcp
!
service-policy global_policy global
service-policy IM_P2P interface inside


!--- Apply the policy map "IM_P2P" !--- to the inside interface.


prompt hostname context
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CiscoASA#

regex _default_GoToMyPC-tunnel "machinekey"
regex _default_GoToMyPC-tunnel_2 "[/\\]erc[/\\]Poll"
regex _default_yahoo-messenger "YMSG"
regex _default_httport-tunnel "photo[.]exectech[-]va[.]com"
regex _default_gnu-http-tunnel_uri "[/\\]index[.]html"
regex _default_firethru-tunnel_1 "firethru[.]com"
regex _default_gator "Gator"
regex _default_firethru-tunnel_2 "[/\\]cgi[-]bin[/\\]proxy"
regex _default_shoutcast-tunneling-protocol "1"
regex _default_http-tunnel "[/\\]HT_PortLog.aspx"
regex _default_x-kazaa-network "[xX]-[kK][aA][zZ][aA][aA]-[nN][eE][tT][wW][oO][rR][kK]"
regex _default_msn-messenger "[Aa][Pp][Pp][Ll][Ii][Cc][Aa][Tt][Ii][Oo][Nn][/\\][Xx][-][Mm][Ss][Nn][-]
[Mm][Ee][Ss][Ss][Ee][Nn][Gg][Ee][Rr]"
regex _default_aim-messenger "[Hh][Tt][Tt][Pp][.][Pp][Rr][Oo][Xx][Yy][.][Ii][Cc][Qq][.][Cc][Oo][Mm]"
regex _default_gnu-http-tunnel_arg "crap"
regex _default_icy-metadata "[iI][cC][yY]-[mM][eE][tT][aA][dD][aA][tT][aA]"
regex _default_windows-media-player-tunnel "NSPlayer"

CiscoASA#show running-config
: Saved
:
ASA Version 8.0(2)
!
hostname pixfirewall
enable password 8Ry2YjIyt7RRXU24 encrypted
names
!
interface Ethernet0
 nameif inside
 security-level 100
 ip address 10.1.1.1 255.255.255.0
!
interface Ethernet1
 nameif outside
 security-level 0
 ip address 192.168.1.1 255.255.255.0
!


!--- Output Suppressed



passwd 2KFQnbNIdI.2KYOU encrypted
ftp mode passive

access-list 101 extended deny ip host 10.1.1.5 any
access-list 101 extended deny ip host 10.1.1.10 any
access-list 101 extended permit ip any any


!--- The ACL statement 101 is meant for deny the IP !--- traffic from the hosts 10.1.1.5 and 10.1.1.10 !--- whereas it allows the rest of the hosts.


pager lines 24
mtu inside 1500
mtu outside 1500
no failover
icmp unreachable rate-limit 1 burst-size 1
no asdm history enable
arp timeout 14400
timeout xlate 3:00:00
timeout conn 1:00:00 half-closed 0:10:00 udp 0:02:00 icmp 0:00:02
timeout sunrpc 0:10:00 h323 0:05:00 h225 1:00:00 mgcp 0:05:00 mgcp-pat
timeout sip 0:30:00 sip_media 0:02:00 sip-invite 0:03:00 sip-disconnect
timeout uauth 0:05:00 absolute
dynamic-access-policy-record DfltAccessPolicy
no snmp-server location
no snmp-server contact
snmp-server enable traps snmp authentication linkup linkdown coldstart
no crypto isakmp nat-traversal
telnet timeout 5
ssh timeout 5
console timeout 0
threat-detection basic-threat
threat-detection statistics access-list
!
class-map type inspect im match-all im-traffic
 match protocol msn-im yahoo-im


!--- The class map "im-traffic" matches all the IM traffic !--- such as msn-im and yahoo-im.



class-map im_inspection
 match access-list 101


!--- The class map "im_inspection" matches the access list !--- number 101.


class-map inspection_default
 match default-inspection-traffic
!
!
policy-map type inspect dns preset_dns_map
 parameters
  message-length maximum 512
policy-map global_policy
 class inspection_default
  inspect dns preset_dns_map
  inspect ftp
  inspect h323 h225
  inspect h323 ras
  inspect netbios
  inspect rsh
  inspect rtsp
  inspect skinny
  inspect esmtp
  inspect sqlnet
  inspect sunrpc
  inspect tftp
  inspect sip
  inspect xdmcp
policy-map type inspect im im-policy
 parameters
 class im-traffic
  drop-connection log


!--- The policy map "im-policy" drops and logs the !--- IM traffic such as msn-im and yahoo-im.



policy-map impol
 class im_inspection
  inspect im im-policy


!--- The policy map "impol" inspects the IM traffic !--- as per traffic matched by the class map "im_inspection". !--- So, it allows the IM traffic from the host 10.1.1.5 !--- and 10.1.1.10 whereas it blocks from rest.


!
service-policy global_policy global
service-policy impol interface inside


!--- Apply the policy map "impol" to the inside !--- interface.


prompt hostname context
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