CONFIGURING ASA,, LAN-to-LAN IPSec VPN with Overlapping Networks Configuration, Example

 

Head office  ASA Configuration
Interface	E0/0	E0/1
IP Address	172.162.1.1	192.168.1.1
Net mask	255.255.255.0	255.255.255.0
Branch Office ASA Configuration
Interface	E0/0	E0/1
IP Address	172.162.1.2	192.168.2.1
Net mask	255.255.255.0	255.255.255.0
HO -USER1 Router
Interface	E1/0
IP Address	192.168.1.10
Net mask	255.255.255.0
HO –USER2 Router
Interface	E1/0
IP Address	192.168.1.11
Net mask	255.255.255.0
BO -USER1 Router
Interface	E1/0
IP Address	192.168.1.10
Net mask	255.255.255.0
BO –USER2 Router
Interface	E1/0
IP Address	192.168.1.11
Net mask	255.255.255.0

NETWORK USED TO OVERCOME NETWORK OVERLAPPING

HO OFFICE NETEWORK: 192.168.2.0 /24

BO OFFICE NETWORK: 192.168.3.0 /24

ASA HO  CONFIGURATION

HO# show run

: Saved

:

ASA Version 8.0(2)

!

hostname HO

enable password 8Ry2YjIyt7RRXU24 encrypted

names

!

interface Ethernet0/0

 nameif outside

 security-level 0

 ip address 172.162.1.1 255.255.255.0

!

interface Ethernet0/1

 nameif inside

 security-level 100

 ip address 192.168.1.1 255.255.255.0

!

access-list new extended permit ip 192.168.2.0 255.255.255.0 192.168.3.0 255.255.255.0

access-list policy-nat extended permit ip 192.168.1.0 255.255.255.0 192.168.3.0 255.255.255.0

pager lines 24

mtu outside 1500

mtu inside 1500

no failover

icmp unreachable rate-limit 1 burst-size 1

no asdm history enable

arp timeout 14400

global (outside) 1 interface

nat (inside) 1 0.0.0.0 0.0.0.0

static (inside,outside) 192.168.2.0  access-list policy-nat

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 0:05:00

timeout sip 0:30:00 sip_media 0:02:00 sip-invite 0:03:00 sip-disconnect 0:02:00

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

crypto ipsec transform-set CISCO esp-des esp-md5-hmac

crypto map outside_map 20 match address new

crypto map outside_map 20 set peer 172.162.1.2

crypto map outside_map 20 set transform-set CISCO

crypto map outside_map interface outside

crypto isakmp identity address

crypto isakmp enable outside

crypto isakmp policy 65535

 authentication pre-share

 encryption des

 hash md5

 group 2

 lifetime 86400

telnet timeout 5

ssh timeout 5

console timeout 0

threat-detection basic-threat

threat-detection statistics access-list

!

!

tunnel-group 172.162.1.2 type ipsec-l2l

tunnel-group 172.162.1.2 ipsec-attributes

 pre-shared-key  12345678

prompt hostname context

Cryptochecksum:00000000000000000000000000000000

: end

HO#

ASA BO CONFIGURATION

BO# SHOW RUN

: Saved

:

ASA Version 8.0(2)

!

hostname BO

enable password 8Ry2YjIyt7RRXU24 encrypted

names

!

interface Ethernet0/0

 nameif outside

 security-level 0

 ip address 172.162.1.2 255.255.255.0

!

interface Ethernet0/1

 nameif inside

 security-level 100

 ip address 192.168.1.1 255.255.255.0

!

passwd 2KFQnbNIdI.2KYOU encrypted

ftp mode passive

access-list new extended permit ip 192.168.3.0 255.255.255.0 192.168.2.0 255.255.255.0

access-list policy-nat extended permit ip 192.168.1.0 255.255.255.0 192.168.2.0 255.255.255.0

pager lines 24

mtu outside 1500

mtu inside 1500

no failover

icmp unreachable rate-limit 1 burst-size 1

no asdm history enable

arp timeout 14400

global (outside) 1 interface

nat (inside) 1 0.0.0.0 0.0.0.0

static (inside,outside) 192.168.3.0  access-list policy-nat

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 0:05:00

timeout sip 0:30:00 sip_media 0:02:00 sip-invite 0:03:00 sip-disconnect 0:02:00

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

crypto ipsec transform-set CISCO esp-des esp-md5-hmac

crypto map outside_map 20 match address new

crypto map outside_map 20 set peer 172.162.1.1

crypto map outside_map 20 set transform-set CISCO

crypto map outside_map interface outside

crypto isakmp identity address

crypto isakmp enable outside

crypto isakmp policy 65535

 authentication pre-share

 encryption des

 hash md5

 group 2

 lifetime 86400

telnet timeout 5

ssh timeout 5

console timeout 0

threat-detection basic-threat

threat-detection statistics access-list

!

!

tunnel-group 172.162.1.1 type ipsec-l2l

tunnel-group 172.162.1.1 ipsec-attributes

 pre-shared-key  12345678

prompt hostname context

Cryptochecksum:00000000000000000000000000000000

: end

BO#

HO -USER1 ROUTER CONFIGURATION

hostname HO_USER1

!

interface Ethernet1/0

 ip address 192.168.1.10 255.255.255.0

 no shut

!

ip route 0.0.0.0 0.0.0.0 192.168.1.1

HO -USER2 ROUTER CONFIGURATION

hostname HO_USER2

!

interface Ethernet1/0

 ip address 192.168.1.11 255.255.255.0

 no shut

!

ip route 0.0.0.0 0.0.0.0 192.168.1.1

BO -USER1 ROUTER CONFIGURATION

hostname BO_USER1

!

interface Ethernet1/0

 ip address 192.168.1.10 255.255.255.0

 no shut

!

ip route 0.0.0.0 0.0.0.0 192.168.1.1

BO -USER2 ROUTER CONFIGURATION

hostname BO_USER2

!

interface Ethernet1/0

 ip address 192.168.1.11 255.255.255.0

 no shut

!

ip route 0.0.0.0 0.0.0.0 192.168.1.1

Testing

Ping from HO-USER1 ROUTER to BO-USER1 ROUTER

HO_USER1# ping 192.168.3.10

Ping from BO-USER2 ROUTER to HO-USER2 ROUTER

BO_USER2# ping 192.168.2.11