09-11-2014 08:27 AM - edited 02-21-2020 05:16 AM
Hi Community
Below is a config example but I'd like to understand how the ACL's work on the BVI and dialer0 interface. The BVI has OUTBOUND-ACL coming IN which is permit ip any any, however the dialer0 interface has INBOUND-ACL coming IN which only has a host and a external network for telnet and deny everything else, so how do users still manage to get out to the internet when the returning traffic coming back IN to the dialer0 interface has a deny all....
Thanks in advance for your assistance...
ip dhcp pool DHCP_POOL
import all
network 192.168.1.0 255.255.255.0
default-router 192.168.1.254
dns-server 208.****
domain-name *****
!
!
ip cef
ip inspect name FIREWALL tcp
ip inspect name FIREWALL udp
ip inspect name FIREWALL ftp
ip inspect name FIREWALL icmp
ip inspect name FIREWALL cuseeme
ip inspect name FIREWALL h323
ip inspect name FIREWALL rcmd
ip inspect name FIREWALL realaudio
ip inspect name FIREWALL rtsp
ip inspect name FIREWALL sqlnet
ip inspect name FIREWALL streamworks
ip inspect name FIREWALL tftp
ip inspect name FIREWALL vdolive
no ip domain lookup
ip domain name *****
ip name-server 20.*.*.*
ip name-server 20.*.*.*
vpdn enable
vpdn-group pptp
! Default PPTP VPDN group
accept-dialin
protocol pptp
virtual-template 1
!
!
!
crypto pki trustpoint sshcert
revocation-check crl
rsakeypair sshcert
!
!
!
!
!
crypto isakmp policy 1
encr aes 256
authentication pre-share
!
crypto isakmp policy 20
encr aes
authentication pre-share
group 5
crypto isakmp key **** address ********
crypto isakmp key **** address **********
!
crypto ipsec security-association lifetime seconds 28800
!
crypto ipsec transform-set VPN-TRANSET esp-aes 256 esp-sha-hmac
!
crypto map VPN-CRYPTOMAP 10 ipsec-isakmp
set peer ********
set transform-set VPN-TRANSET
match address VPNTRAFFIC-ACL
crypto map VPN-CRYPTOMAP 20 ipsec-isakmp
set peer ********
set transform-set VPN-TRANSET
match address HS-VPNTRAFFIC-ACL
!
bridge irb
!
!
interface ATM0
no ip address
no ip redirects
no ip unreachables
no atm ilmi-keepalive
pvc 0/38
encapsulation aal5mux ppp dialer
dialer pool-member 1
!
dsl operating-mode auto
!
interface FastEthernet0
!
interface FastEthernet1
!
interface FastEthernet2
!
interface FastEthernet3
!
interface Virtual-Template1
ip unnumbered BVI1
ip mroute-cache
peer default ip address pool pptp
ppp encrypt mppe auto required
ppp authentication ms-chap-v2 ms-chap
!
interface Vlan1
no ip address
bridge-group 1
!
interface Dialer0
ip address negotiated
ip access-group INBOUND-ACL in
no ip redirects
no ip unreachables
no ip proxy-arp
ip mtu 1492
ip inspect FIREWALL out
ip nat outside
ip virtual-reassembly
encapsulation ppp
dialer pool 1
dialer-group 1
no cdp enable
ppp authentication chap callin
ppp chap hostname **********
ppp chap password ***********
crypto map VPN-CRYPTOMAP
!
interface BVI1
ip address 192.168.1.254 255.255.255.0
ip access-group OUTBOUND-ACL in
ip nat inside
ip virtual-reassembly
!
ip local pool pptp 192.168.1.201 192.168.1.220
ip route 0.0.0.0 0.0.0.0 Dialer0
!
ip nat source static 192.168.1.2 #.#.#.# route-map NAT-MAP extendable
ip nat inside source static tcp 192.168.1.2 80 interface Dialer0 80
ip nat inside source static tcp 192.168.1.2 443 interface Dialer0 443
ip nat inside source static tcp 192.168.1.1 3389 interface Dialer0 3389
ip nat inside source static tcp 192.168.1.2 25 interface Dialer0 25
ip nat inside source route-map NAT-MAP interface Dialer0 overload
!
ip access-list extended HS-VPNTRAFFIC-ACL
permit ip 192.168.0.0 0.0.0.255 172.*.*.* *.*.*.*
ip access-list extended INBOUND-ACL
deny ip 10.0.0.0 0.255.255.255 any
deny ip 172.16.0.0 0.15.255.255 any
deny ip 192.168.0.0 0.0.255.255 any
deny ip 127.0.0.0 0.255.255.255 any
deny ip host 255.255.255.255 any
deny ip host 0.0.0.0 any
permit tcp any any eq 1723
permit gre any any
permit icmp any any echo-reply
permit icmp any any time-exceeded
permit icmp any any unreachable
permit tcp host #.#.#.# any eq 22
permit tcp *.*.* *.*.*.* any eq 22
deny tcp any any eq smtp
deny ip any any
ip access-list extended NONVPNTRAFFIC-ACL
deny ip 192.168.1.0 0.0.0.255 10.0.0.0 0.0.0.255
deny ip 192.168.1.0 0.0.0.255 172.0.0.0 0.0.0.255
permit ip 192.168.1.0 0.0.0.255 any
ip access-list extended OUTBOUND-ACL
deny ip host 255.255.255.255 any
deny ip 127.0.0.0 0.255.255.255 any
permit ip any any
ip access-list extended VPNTRAFFIC-ACL
permit ip 192.168.1.0 0.0.0.255 10.0.0.0 0.0.0.255
ip access-list extended VTY-ACL
permit ip 192.168.1.0 0.0.0.255 any
permit ip #.#.#.# #.#.#.# any
!
route-map NAT-MAP permit 10
match ip address NONVPNTRAFFIC-ACL
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