Table Of Contents

Site-to-Site VPN Configuration Examples

Using Pre-Shared Keys

Scenario Description

Configuring PIX Firewall 1 with VPN Tunneling

Configuring PIX Firewall 2 for VPN Tunneling

Using PIX Firewall with a VeriSign CA

Scenario Description

Configuring PIX Firewall 1 with a VeriSign CA

Configuring PIX Firewall 2 with a VeriSign CA

Using PIX Firewall with an In-House CA

Scenario Description

Configuring PIX Firewall 1 for an In-House CA

Configuring PIX Firewall 2 for an In-House CA

Using an Encrypted Tunnel to Obtain Certificates

Establishing a Tunnel Using a Pre-Shared Key

PIX Firewall 1 Configuration

PIX Firewall 2 Configuration

Establishing a Tunnel with a Certificate

PIX Firewall 1 Configuration

PIX Firewall 2 Configuration

Connecting to a Catalyst 6500 and Cisco 7600 Series IPSec VPN Services Module

Scenario Description

Configuring IPSec Using a Trunk Port

Configuring IPSec Using a Routed Port

Verifying Your Configuration

Manual Configuration with NAT

PIX Firewall 1 Configuration

PIX Firewall 2 Configuration

Site-to-Site VPN Configuration Examples

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A site-to-site VPN protects the network resources on your protected networks from unauthorized use by users on an unprotected network, such as the public Internet. The basic configuration for this type of implementation has been covered in Chapter 6, "Configuring IPSec and Certification Authorities." This chapter provides examples of the following site-to-site VPN configurations:

•Using Pre-Shared Keys

•Using PIX Firewall with a VeriSign CA

•Using PIX Firewall with an In-House CA

•Using an Encrypted Tunnel to Obtain Certificates

•Connecting to a Catalyst 6500 and Cisco 7600 Series IPSec VPN Services Module

•Manual Configuration with NAT

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Note Throughout the examples in this chapter, the local PIX Firewall unit is identified as PIX Firewall 1 while the remote unit is identified as PIX Firewall 2. This designation makes it easier to clarify the configuration required for each.

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Using Pre-Shared Keys

This section describes an example configuration for using pre-shared keys. It contains the following topics:

•Scenario Description

•Configuring PIX Firewall 1 with VPN Tunneling

•Configuring PIX Firewall 2 for VPN Tunneling

Scenario Description

In the example illustrated in Figure 7-1, the intranets use unregistered addresses and are connected over the public Internet by a site-to-site VPN. In this scenario, NAT is required for connections to the public Internet. However, NAT is not required for traffic between the two intranets, which can be transmitted using a VPN tunnel over the public Internet.

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Note If you do not need to do VPN tunneling for intranet traffic, you can use this example without the access-list or the nat 0 access-list commands. These commands disable NAT for traffic that matches the access list criteria.

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If you have a limited number of registered IP addresses and you cannot use PAT, you can configure PIX Firewall to use NAT for connections to the public Internet, but avoid NAT for traffic between the two intranets. This configuration might also be useful if you were replacing a direct, leased-line connection between two intranets.

Figure 7-1 VPN Tunnel Network

The configuration shown for this example uses an access list to exclude traffic between the two intranets from NAT. The configuration assigns a global pool of registered IP addresses for use by NAT for all other traffic. By excluding intranet traffic from NAT, you need fewer registered IP addresses.

Configuring PIX Firewall 1 with VPN Tunneling

Follow these steps to configure PIX Firewall 1:

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Step 1 Define a host name:

hostname NewYork

Step 2 Configure an ISAKMP policy:

isakmp enable outside

isakmp policy 9 authentication pre-share

isakmp policy 9 encrypt 3des

Step 3 Configure a pre-shared key and associate with the peer:

crypto isakmp key cisco1234 address 209.165.200.229

Step 4 Configure the supported IPSec transforms:

crypto ipsec transform-set strong esp-3des esp-sha-hmac

Step 5 Create an access list:

access-list 90 permit ip 192.168.12.0 255.255.255.0 10.0.0.0 255.0.0.0

This access list defines traffic from network 192.168.12.0 to 10.0.0.0. Both of these networks use unregistered addresses.

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Note Steps 5 and 6 are not required if you want to enable NAT for all traffic.

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Step 6 Exclude traffic between the intranets from NAT:

nat 0 access-list 90

This excludes traffic matching access list 90 from NAT. The nat 0 command is always processed before any other nat commands.

Step 7 Enable NAT for all other traffic:

nat (inside) 1 0 0

Step 8 Assign a pool of global addresses for NAT and PAT:

global (outside) 1 209.165.201.9-209.165.201.30

global (outside) 1 209.165.201.8

The pool of registered addresses are only used for connections to the public Internet.

Step 9 Define a crypto map:

crypto map toSanJose 20 ipsec-isakmp 

crypto map toSanJose 20 match address 90

crypto map toSanJose 20 set transform-set strong

crypto map toSanJose 20 set peer 209.165.200.229

Step 10 Apply the crypto map to the outside interface:

crypto map toSanJose interface outside

Step 11 Specify that IPSec traffic be implicitly trusted (permitted):

sysopt connection permit-ipsec

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Example 7-1 lists the configuration for PIX Firewall 1.

Example 7-1 PIX Firewall 1 VPN Tunnel Configuration

nameif ethernet0 outside security0

nameif ethernet1 inside security100

interface ethernet0 auto

interface ethernet1 auto

enable password 8Ry2YjIyt7RRXU24 encrypted

passwd 2KFQnbNIdI.2KYOU encrypted

hostname NewYork

domain-name example.com

fixup protocol ftp 21

fixup protocol http 80

fixup protocol smtp 25

fixup protocol h323 1720

fixup protocol rsh 514

fixup protocol sqlnet 1521

names

pager lines 24

no logging on

mtu outside 1500

mtu inside 1500

ip address outside 209.165.201.8 255.255.255.224

ip address inside 192.168.12.1 255.255.255.0

no failover

failover ip address outside 0.0.0.0

failover ip address inside 0.0.0.0

arp timeout 14400

nat (inside) 0 access-list 90

access-list 90 permit ip 192.168.12.0 255.255.255.0 10.0.0.0 255.0.0.0

nat (inside) 1 0 0

global (outside) 1 209.165.201.9-209.165.201.30

global (outside) 1 209.165.201.8

no rip outside passive

no rip outside default

rip inside passive

no rip inside default

route outside 0.0.0.0 0.0.0.0 209.165.201.7 1

timeout xlate 3:00:00 conn 1:00:00 half-closed 0:10:00 udp 0:02:00

timeout rpc 0:10:00 h323 0:05:00

timeout uauth 0:05:00 absolute

aaa-server TACACS+ protocol tacacs+

aaa-server RADIUS protocol radius

no snmp-server location

no snmp-server contact

snmp-server community public

no snmp-server enable traps

sysopt connection permit-ipsec

crypto ipsec transform-set strong esp-3des esp-sha-hmac

crypto map toSanJose 20 ipsec-isakmp

crypto map toSanJose 20 match address 90

crypto map toSanJose 20 set peer 209.165.200.229

crypto map toSanJose 20 set transform-set strong

crypto map toSanJose interface outside

isakmp enable outside

isakmp key cisco1234 address 209.165.200.229 netmask 255.255.255.255

isakmp policy 9 authentication pre-share

isakmp policy 9 encryption 3des

telnet timeout 5

terminal width 80

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Note In this example, the following statements are not used when enabling NAT for all traffic:
nat 0 access-list 90
access-list 90 permit ip 192.168.12.0 255.255.255.0 10.0.0.0 255.0.0.0

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Configuring PIX Firewall 2 for VPN Tunneling

Follow these steps to configure PIX Firewall 2:

---

Step 1 Define a host name:

hostname SanJose

Step 2 Define the domain name:

domain-name example.com

Step 3 Configure the ISAKMP policy:

isakmp enable outside

isakmp policy 8 authentication pre-share

isakmp policy 8 encryption 3des

Step 4 Configure a pre-shared key and associate it with the peer:

crypto isakmp key cisco1234 address 209.165.201.8

Step 5 Configure IPSec supported transforms:

crypto ipsec transform-set strong esp-3des esp-sha-hmac

Step 6 Create an access list:

access-list 80 permit ip 10.0.0.0 255.0.0.0 192.168.12.0 255.255.255.0

This access list defines traffic from network 10.0.0.0 to 192.168.12.0. Both of these networks use unregistered addresses.

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Note Step 7 and Step 8 are not required if you want to enable NAT for all traffic.

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Step 7 Exclude traffic between the intranets from NAT:

nat 0 access-list 80

This excludes traffic matching access list 80 from NAT. The nat 0 command is always processed before any other nat commands.

Step 8 Enable NAT for all other traffic:

nat (inside) 1 0 0

Step 9 Assign a pool of global addresses for NAT and PAT:

global (outside) 1 209.165.200.240-209.165.200.250

global (outside) 1 209.165.202.251

The pool of registered addresses are only used for connections to the public Internet.

Step 10 Define a crypto map:

crypto map newyork 10 ipsec-isakmp 

crypto map newyork 10 match address 80

crypto map newyork 10 set transform-set strong

crypto map newyork 10 set peer 209.165.201.8

Step 11 Apply the crypto map to an interface:

crypto map newyork interface outside

Step 12 Specify that IPSec traffic be implicitly trusted (permitted):

sysopt connection permit-ipsec

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Example 7-2 lists the configuration for PIX Firewall 2.

Example 7-2 PIX Firewall 2 VPN Tunnel Configuration

nameif ethernet0 outside security0

nameif ethernet1 inside security100

nameif ethernet2 dmz security50

nameif ethernet3 perimeter security40

enable password 8Ry2YjIyt7RRXU24 encrypted

passwd 2KFQnbNIdI.2KYOU encrypted

hostname SanJose

domain-name example.com

fixup protocol ftp 21

fixup protocol http 80

fixup protocol smtp 25

fixup protocol h323 1720

fixup protocol rsh 514

fixup protocol sqlnet 1521

names

pager lines 24

no logging on

interface ethernet0 auto

interface ethernet1 auto

interface ethernet2 auto

interface ethernet3 auto

mtu outside 1500

mtu inside 1500

mtu dmz 1500

mtu perimeter 1500

ip address outside 209.165.200.229 255.255.255.224

ip address inside 10.0.0.1 255.0.0.0

ip address dmz 192.168.101.1 255.255.255.0

ip address perimeter 192.168.102.1 255.255.255.0

no failover

failover ip address outside 0.0.0.0

failover ip address inside 0.0.0.0

failover ip address dmz 0.0.0.0

failover ip address perimeter 0.0.0.0

arp timeout 14400

nat 0 access-list 80

access-list 80 permit ip 10.0.0.0 255.0.0.0 192.168.12.0 255.255.255.0

nat (inside) 1 0 0

global (outside) 1 209.165.200.240-209.165.200.250

global (outside) 1 209.165.202.251

no rip outside passive

no rip outside default

no rip inside passive

no rip inside default

no rip dmz passive

no rip dmz default

no rip perimeter passive

no rip perimeter default

route outside 0.0.0.0 0.0.0.0 209.165.200.228 1

timeout xlate 3:00:00 conn 1:00:00 half-closed 0:10:00 udp 0:02:00

timeout rpc 0:10:00 h323 0:05:00

timeout uauth 0:05:00 absolute

aaa-server TACACS+ protocol tacacs+

aaa-server RADIUS protocol radius

no snmp-server location

no snmp-server contact

snmp-server community public

no snmp-server enable traps

sysopt connection permit-ipsec

crypto ipsec transform-set strong esp-3des esp-sha-hmac

crypto map newyork 10 ipsec-isakmp

crypto map newyork 10 match address 80

crypto map newyork 10 set peer 209.165.201.8

crypto map newyork 10 set transform-set strong

crypto map newyork interface outside

isakmp enable outside

isakmp key cisco1234 address 209.165.201.8 netmask 255.255.255.255

isakmp policy 8 authentication pre-share

isakmp policy 8 encryption 3des

telnet timeout 5

terminal width 80

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Note In Example 7-2, the following statements are not used when enabling NAT for all traffic:
nat 0 access-list 80
access-list 80 permit ip 10.0.0.0 255.0.0.0 192.168.12.0 255.255.255.00

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Using PIX Firewall with a VeriSign CA

This section provides configuration examples showing how to configure interoperability between two PIX Firewall units (PIX Firewall 1 and 2) for site-to-site VPN using the VeriSign CA server for device enrollment, certificate requests, and digital certificates for the IKE authentication. This section includes the following topics:

•Scenario Description

•Configuring PIX Firewall 1 with a VeriSign CA

•Configuring PIX Firewall 2 with a VeriSign CA

Scenario Description

The two VPN peers in the configuration examples are shown to be configured to enroll with VeriSign at the IP address of 209.165.202.130 and to obtain their CA certificates from this CA server. VeriSign is a public CA that issues its CA-signed certificates over the Internet. Once each peer obtains its CA-signed certificate, tunnels can be established between the two VPN peers using digital certificates as the authentication method used during IKE authentication. The peers dynamically authenticate each other using the digital certificates.

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Note VeriSign's actual CA server address differs. The example CA server address is to be used for example purposes only.

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For the general procedures to configure the PIX Firewall for a CA, see "Using Certification Authorities" in Chapter 6, "Configuring IPSec and Certification Authorities."

This section provides an example configuration for the specific network illustrated in Figure 7-2.

Figure 7-2 VPN Tunnel Network

Configuring PIX Firewall 1 with a VeriSign CA

Perform the following steps to configure PIX Firewall 1 to use a public CA:

---

Step 1 Define a host name:

hostname NewYork

Step 2 Define the domain name:

domain-name example.com

Step 3 Generate the PIX Firewall RSA key pair:

ca generate rsa key 512

This command is not stored in the configuration.

Step 4 Define VeriSign-related enrollment commands:

ca identity example.com 209.165.202.130

ca configure example.com ca 2 20 crloptional

These commands are stored in the configuration. "2" is the retry period, "20" is the retry count, and the crloptional option disables CRL checking.

Step 5 Authenticate the CA by obtaining its public key and its certificate:

ca authenticate example.com

This command is not stored in the configuration.

Step 6 Request signed certificates from your CA for your PIX Firewall's RSA key pair. Before entering this command, contact your CA administrator because they will have to authenticate your PIX Firewall manually before granting its certificate.

ca enroll example.com abcdef

"abcdef" is a challenge password. This can be anything. This command is not stored in the configuration.

Step 7 Verify that the enrollment process was successful using the show ca certificate command:

show ca certificate

Step 8 Save keys and certificates, and the CA commands (except those indicated) in Flash memory:

ca save all

write memory

---

Note Use the ca save all command any time you add, change, or delete ca commands in the configuration. This command is not stored in the configuration.

---

Step 9 Configure an IKE policy:

isakmp enable outside

isakmp policy 8 auth rsa-sig

Step 10 Create a partial access list:

access-list 90 permit ip 192.168.12.0 255.255.255.0 10.0.0.0 255.0.0.0

Step 11 Configure a transform set that defines how the traffic will be protected:

crypto ipsec transform-set strong esp-3des esp-sha-hmac

Step 12 Define a crypto map:

crypto map toSanJose 20 ipsec-isakmp 

crypto map toSanJose 20 match address 90

crypto map toSanJose 20 set transform-set strong

crypto map toSanJose 20 set peer 209.165.200.229

Step 13 Apply the crypto map to the outside interface:

crypto map toSanJose interface outside

Step 14 Tell the PIX Firewall to implicitly permit IPSec traffic:

sysopt connection permit-ipsec

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Example 7-3 lists the configuration for PIX Firewall 1. PIX Firewall default configuration values and certain CA commands are not displayed in configuration listings.

Example 7-3 PIX Firewall 1 with Public CA

nameif ethernet0 outside security0

nameif ethernet1 inside security100

enable password 8Ry2YjIyt7RRXU24 encrypted

passwd 2KFQnbNIdI.2KYOU encrypted

hostname NewYork

domain-name example.com

fixup protocol ftp 21

fixup protocol http 80

fixup protocol smtp 25

fixup protocol h323 1720

fixup protocol rsh 514

fixup protocol sqlnet 1521

names

pager lines 24

no logging on

interface ethernet0 auto

interface ethernet1 auto

mtu outside 1500

mtu inside 1500

ip address outside 209.165.201.8 255.255.255.224

ip address inside 192.168.12.1 255.255.255.0

no failover

failover ip address outside 0.0.0.0

failover ip address inside 0.0.0.0

arp timeout 14400

nat (inside) 0 0.0.0.0 0.0.0.0 0 0

nat 0 access-list 90

access-list 90 permit ip 192.168.12.0 255.255.255.0 10.0.0.0 255.0.0.0

no rip outside passive

no rip outside default

rip inside passive

no rip inside default

route outside 0.0.0.0 0.0.0.0 209.165.201.7 1

timeout xlate 3:00:00 conn 1:00:00 half-closed 0:10:00 udp 0:02:00

timeout rpc 0:10:00 h323 0:05:00

timeout uauth 0:05:00 absolute

aaa-server TACACS+ protocol tacacs+

aaa-server RADIUS protocol radius

no snmp-server location

no snmp-server contact

snmp-server community public

no snmp-server enable traps

sysopt connection permit-ipsec

crypto ipsec transform-set strong esp-3des esp-sha-hmac

crypto map toSanJose 20 ipsec-isakmp

crypto map toSanJose 20 match address 90

crypto map toSanJose 20 set peer 209.165.200.229

crypto map toSanJose 20 set transform-set strong

crypto map toSanJose interface outside

isakmp policy 8 authentication rsa-sig

isakmp policy 8 encryption des

isakmp policy 8 hash sha

isakmp policy 8 group 1

isakmp policy 8 lifetime 86400

ca identity example.com 209.165.202.130:cgi-bin/pkiclient.exe

ca configure example.com ca 1 100 crloptional

telnet timeout 5

terminal width 80

Configuring PIX Firewall 2 with a VeriSign CA

---

Note The following steps are nearly the same as those in the previous section "Configuring PIX Firewall 1 with a VeriSign CA" for configuring PIX Firewall 2. The differences are in Steps 1 and 2, and Steps 11 to 13, which are specific for the PIX Firewall 2 in this example.

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Perform the following steps to configure PIX Firewall 2 for using a VeriSign CA:

---

Step 1 Define a host name:

hostname SanJose

Step 2 Define the domain name:

domain-name example.com

Step 3 Generate the PIX Firewall RSA key pair:

ca generate rsa key 512

This command is not stored in the configuration.

Step 4 Define VeriSign-related enrollment commands:

ca identity example.com 209.165.202.130

ca configure example.com ca 2 20 crloptional

These commands are stored in the configuration. "2" is the retry period, "20" is the retry count, and the crloptional option disables CRL checking.

Step 5 Authenticate the CA by obtaining its public key and its certificate:

ca authenticate example.com

This command is not stored in the configuration.

Step 6 Request signed certificates from your CA for your PIX Firewall's RSA key pair:

ca enroll example.com abcdef

Before entering this command, contact your CA administrator because they will have to authenticate your PIX Firewall manually before granting its certificate.

"abcdef" is a challenge password. This can be anything. This command is not stored in the configuration.

Step 7 Verify that the enrollment process was successful using the following command:

show ca certificate

Step 8 Save keys and certificates, and the CA commands (except those indicated) in Flash memory:

ca save all

write memory

---

Note Use the ca save all command any time you add, change, or delete ca commands in the configuration. This command is not stored in the configuration.

---

Step 9 Configure an IKE policy:

isakmp enable outside

isakmp policy 8 auth rsa-sig

Step 10 Create a partial access list:

access-list 80 permit ip 10.0.0.0 255.0.0.0 192.168.12.0 255.255.255.0

Step 11 Configure a transform set that defines how the traffic will be protected:

crypto ipsec transform-set strong esp-3des esp-sha-hmac

Step 12 Define a crypto map:

crypto map newyork 10 ipsec-isakmp 

crypto map newyork 10 match address 80

crypto map newyork 10 set transform-set strong

crypto map newyork 10 set peer 209.165.201.8

Step 13 Apply the crypto map to the outside interface:

crypto map newyork interface outside

Step 14 Tell the PIX Firewall to implicitly permit IPSec traffic:

sysopt connection permit-ipsec

---

Example 7-4 lists the configuration for PIX Firewall 2. PIX Firewall default configuration values and certain CA commands are not displayed in a configuration listing.

Example 7-4 PIX Firewall 2 CA Configuration

nameif ethernet0 outside security0

nameif ethernet1 inside security100

nameif ethernet2 dmz security50

nameif ethernet3 perimeter security40

enable password 8Ry2YjIyt7RRXU24 encrypted

passwd 2KFQnbNIdI.2KYOU encrypted

hostname SanJose

domain-name example.com

fixup protocol ftp 21

fixup protocol http 80

fixup protocol smtp 25

fixup protocol h323 1720

fixup protocol rsh 514

fixup protocol sqlnet 1521

names

pager lines 24

no logging on

interface ethernet0 auto

interface ethernet1 auto

interface ethernet2 auto

interface ethernet3 auto

mtu outside 1500

mtu inside 1500

mtu dmz 1500

mtu perimeter 1500

ip address outside 209.165.200.229 255.255.255.224

ip address inside 10.0.0.1 255.0.0.0

ip address dmz 192.168.101.1 255.255.255.0

ip address perimeter 192.168.102.1 255.255.255.0

no failover

failover ip address outside 0.0.0.0

failover ip address inside 0.0.0.0

failover ip address dmz 0.0.0.0

failover ip address perimeter 0.0.0.0

arp timeout 14400

nat (inside) 0 10.0.0.0 255.0.0.0 0 0

nat 0 access-list 80

access-list 80 permit ip 10.0.0.0 255.0.0.0 192.168.12.0 255.255.255.0

no rip outside passive

no rip outside default

no rip inside passive

no rip inside default

no rip dmz passive

no rip dmz default

no rip perimeter passive

no rip perimeter default

route outside 0.0.0.0 0.0.0.0 209.165.200.228 1

timeout xlate 3:00:00 conn 1:00:00 half-closed 0:10:00 udp 0:02:00

timeout rpc 0:10:00 h323 0:05:00

timeout uauth 0:05:00 absolute

aaa-server TACACS+ protocol tacacs+

aaa-server RADIUS protocol radius

no snmp-server location

no snmp-server contact

snmp-server community public

no snmp-server enable traps

sysopt connection permit-ipsec

crypto ipsec transform-set strong esp-3des esp-sha-hmac

crypto map newyork 10 ipsec-isakmp

crypto map newyork 10 match address 80

crypto map newyork 10 set peer 209.165.201.8

crypto map newyork 10 set transform-set strong

crypto map newyork interface outside

isakmp policy 8 authentication rsa-sig

isakmp policy 8 encryption des

isakmp policy 8 hash sha

isakmp policy 8 group 1

isakmp policy 8 lifetime 86400

ca identity example.com 209.165.202.130:cgi-bin/pkiclient.exe

ca configure example.com ca 2 20 crloptional

telnet timeout 5

terminal width 80

Using PIX Firewall with an In-House CA

For the general procedures to configure the PIX Firewall for a CA, see "Using Certification Authorities" in Chapter 6, "Configuring IPSec and Certification Authorities." This section provides a specific example for the network illustrated in Figure 7-3 and includes the following topics:

•Scenario Description

•Configuring PIX Firewall 1 for an In-House CA

•Configuring PIX Firewall 2 for an In-House CA

Scenario Description

PIX Firewall supports the use of the following certification authorities (CAs):

•VeriSign support is provided through the VeriSign Private Certificate Services (PCS) and the OnSite service, which lets you establish an in-house CA system for issuing digital certificates.

•Entrust, Entrust VPN Connector, version 4.1 (build 4.1.0.337) or higher. The Entrust CA server is an in-house CA server solution.

•Baltimore Technologies, UniCERT Certificate Management System, version 3.1.2 or higher. The Baltimore CA server is an in-house CA server solution.

•Microsoft Windows 2000, specifically the Windows 2000 Advanced Server, version 5.00.2195 or higher. The Windows 2000 CA server is an in-house CA server solution.

These are all in-house CA servers, except for VeriSign, which provides both a public CA and a private CA solution.

---

Note The example CA server address is to be used for example purposes only.

---

The in-house CA server in the following example is placed within the DMZ network of one PIX Firewall network (PIX Firewall 1). The VPN peer, PIX Firewall 2, should enroll and obtain its CA-signed certificates from the CA server residing within the network of PIX Firewall 1. PIX Firewall 2's enrollment and certificate request process is accomplished through the Internet.

The two VPN peers in the configuration examples are shown to be configured to enroll with and obtain their CA-signed certificates from the Entrust CA server. PIX Firewall 1 will obtain its certificate from the CA's local IP address of 10.1.0.2. PIX Firewall 2 will obtain its certificate from the CA's global IP address of 209.165.202.131. After each peer obtains its CA-signed certificate, tunnels can be established between the two VPN peers. The peers dynamically authenticate each other using the digital certificates.

Figure 7-3 VPN Tunnel Network

Configuring PIX Firewall 1 for an In-House CA

Follow these steps to configure PIX Firewall 1 for use with an in-house CA. These steps are similar to the procedure shown in "Using PIX Firewall with a VeriSign CA."

---

Step 1 Define a host name:

hostname NewYork

Step 2 Define the domain name:

domain-name example.com

Step 3 Generate the PIX Firewall RSA key pair:

ca generate rsa key 512

This command is entered at the command line and does not get stored in the configuration.

Step 4 Define CA-related enrollment commands:

ca identity abcd 10.1.0.2 10.1.0.2

ca configure abcd ra 2 20 crloptional

These commands are stored in the configuration. 2 is the retry period, 20 is the retry count, and the crloptional option disables CRL checking.

---

Note For a Microsoft CA server, specify the internal network address followed by a colon and the pathname to the server executable, such as 10.1.0.2:/CERTSRV/mscep/mscep.dll.

---

Step 5 Authenticate the CA by obtaining its public key and its certificate:

ca authenticate abcd

This command is entered at the command line and does not get stored in the configuration.

Step 6 Request signed certificates from your CA for your PIX Firewall's RSA key pair:

ca enroll abcd cisco

Before entering this command, contact your CA administrator because they will have to authenticate your PIX Firewall manually before granting its certificate.

"cisco" is a challenge password. This can be anything. This command is entered at the command line and does not get stored in the configuration.

Step 7 Verify that the enrollment process was successful using the show ca certificate command:

show ca certificate

Step 8 Save keys and certificates, and the CA commands (except those indicated) in Flash memory:

ca save all

write memory

---

Note Use the ca save all command any time you add, change, or delete ca commands in the configuration. This command is not stored in the configuration.

---

Step 9 Map a local IP address to a global IP address:

static (dmz, outside) 209.165.202.131 10.1.0.2 netmask 255.255.255.255

Step 10 Permit the host (PIX Firewall 2) to access the global host via LDAP, port 389:

access-list globalhost permit tcp 209.165.200.229 255.255.255.255 host 209.165.202.131 eq 
389

Step 11 Permit the host (PIX Firewall 2) to access the global host via HTTP:

access-list globalhost permit tcp 209.165.200.229 255.255.255.255 host 209.165.202.131 eq 
http 

Step 12 Create an access group to bind the access list to an interface:

access-group globalhost in interface outside 

Step 13 Configure an IKE policy:

isakmp enable outside

isakmp policy 8 auth rsa-sig

isakmp identity hostname

Step 14 Configure a transform set that defines how the traffic will be protected:

crypto ipsec transform-set strong esp-3des esp-sha-hmac

Step 15 Create a partial access list:

access-list 90 permit ip 192.168.12.0 255.255.255.0 10.0.0.0 255.0.0.0

Step 16 Define a crypto map:

crypto map toSanJose 20 ipsec-isakmp 

crypto map toSanJose 20 match address 90

crypto map toSanJose 20 set transform-set strong

crypto map toSanJose 20 set peer 209.165.200.229

Step 17 Apply the crypto map to the outside interface:

crypto map toSanJose interface outside

Step 18 Tell the PIX Firewall to implicitly permit IPSec traffic:

sysopt connection permit-ipsec

---

Example 7-5 lists the configuration for PIX Firewall 1.

Example 7-5 PIX Firewall 1 VPN Tunnel Configuration

nameif ethernet0 outside security0

nameif ethernet1 inside security100

enable password 8Ry2YjIyt7RRXU24 encrypted

passwd 2KFQnbNIdI.2KYOU encrypted

hostname NewYork

domain-name example.com

fixup protocol ftp 21

fixup protocol http 80

fixup protocol smtp 25

fixup protocol h323 1720

fixup protocol rsh 514

fixup protocol sqlnet 1521

names

pager lines 24

no logging on

interface ethernet0 auto

interface ethernet1 auto

mtu outside 1500

mtu inside 1500

ip address outside 209.165.201.8 255.255.255.224

ip address inside 192.168.12.1 255.255.255.0

no failover

failover ip address outside 0.0.0.0

failover ip address inside 0.0.0.0

arp timeout 14400

static (dmz, outside) 209.165.202.131 10.1.0.2 netmask 255.255.255.255

access-list globalhost permit tcp 209.165.200.229 255.255.255.255 host 209.165.202.131 eq 
389

access-list globalhost permit tcp 209.165.200.229 255.255.255.255 host 209.165.202.131 eq 
http

access-group globalhost in interface outside 

nat 0 access-list 90

access-list 90 permit ip 192.168.12.0 255.255.255.0 10.0.0.0 255.0.0.0

no rip outside passive

no rip outside default

rip inside passive

no rip inside default

route outside 0.0.0.0 0.0.0.0 209.165.201.7 1

timeout xlate 3:00:00 conn 1:00:00 half-closed 0:10:00 udp 0:02:00

timeout rpc 0:10:00 h323 0:05:00

timeout uauth 0:05:00 absolute

aaa-server TACACS+ protocol tacacs+

aaa-server RADIUS protocol radius

no snmp-server location

no snmp-server contact

snmp-server community public

no snmp-server enable traps

sysopt connection permit-ipsec

crypto ipsec transform-set strong esp-3des esp-sha-hmac

crypto map toSanJose 20 ipsec-isakmp

crypto map toSanJose 20 match address 90

crypto map toSanJose 20 set peer 209.165.200.229

crypto map toSanJose 20 set transform-set strong

crypto map toSanJose interface outside

isakmp policy 8 authentication rsa-sig

isakmp policy 8 encryption des

isakmp policy 8 hash sha

isakmp policy 8 group 1

isakmp policy 8 lifetime 86400

ca identity abcd 10.1.0.2 10.1.0.2

ca configure abcd ra 1 100 crloptional

telnet timeout 5

terminal width 80

Configuring PIX Firewall 2 for an In-House CA

Follow these steps to configure PIX Firewall 2:

---

Step 1 Define a host name:

hostname SanJose

Step 2 Define the domain name:

domain-name example.com

Step 3 Configure an IKE policy:

isakmp enable outside

isakmp policy 8 auth rsa-sig

Step 4 Define CA-related enrollment commands:

ca identity abcd 209.165.202.131 209.165.202.131

ca configure abcd ra 2 20 crloptional

These commands are stored in the configuration. 2 is the retry period, 20 is the retry count, and the crloptional option disables CRL checking.

---

Note For a Microsoft CA server, specify the external (global) network address followed by a colon and the pathname to the server executable, such as 209.165.202.131:/certserv/mscep/mscep.dll.

---

Step 5 Generate the PIX Firewall RSA key pair:

ca generate rsa key 512

This command is entered at the command line and does not get stored in the configuration.

Step 6 Get the public key and the certificate of the CA server:

ca authenticate abcd

This command is entered at the command line and does not get stored in the configuration.

Step 7 Contact your CA administrator and send your certificate request:

ca enroll abcd cisco

"cisco" is a challenge password. This can be anything. This command is entered at the command line and does not get stored in the configuration.

Step 8 Configure supported IPSec transforms:

crypto ipsec transform-set strong esp-3des esp-sha-hmac

Step 9 Save keys and certificates, and the CA commands (except those indicated) in Flash memory:

ca save all

write memory

---

Note Use the ca save all command any time you add, change, or delete ca commands in the configuration. This command is not stored in the configuration.

---

Step 10 Create a partial access list:

access-list 80 permit ip 10.0.0.0 255.0.0.0 192.168.12.0 255.255.255.0

Step 11 Define a crypto map:

crypto map newyork 20 ipsec-isakmp 

crypto map newyork 20 match address 80

crypto map newyork 20 set transform-set strong

crypto map newyork 20 set peer 209.165.201.8

Step 12 Apply the crypto map to the outside interface:

crypto map newyork interface outside

Step 13 Tell the PIX Firewall to implicitly permit IPSec traffic:

sysopt connection permit-ipsec

---

Example 7-6 lists the configuration for PIX Firewall 2.

Example 7-6 PIX Firewall 2 VPN Tunnel Configuration

nameif ethernet0 outside security0

nameif ethernet1 inside security100

nameif ethernet2 dmz security50

nameif ethernet3 perimeter security40

enable password 8Ry2YjIyt7RRXU24 encrypted

passwd 2KFQnbNIdI.2KYOU encrypted

hostname SanJose

domain-name example.com

fixup protocol ftp 21

fixup protocol http 80

fixup protocol smtp 25

fixup protocol h323 1720

fixup protocol rsh 514

fixup protocol sqlnet 1521

names

pager lines 24

no logging on

interface ethernet0 auto

interface ethernet1 auto

interface ethernet2 auto

interface ethernet3 auto

mtu outside 1500

mtu inside 1500

mtu dmz 1500

mtu perimeter 1500

ip address outside 209.165.200.229 255.255.255.224

ip address inside 10.0.0.1 255.0.0.0

ip address dmz 192.168.101.1 255.255.255.0

ip address perimeter 192.168.102.1 255.255.255.0

no failover

failover ip address outside 0.0.0.0

failover ip address inside 0.0.0.0

failover ip address dmz 0.0.0.0

failover ip address perimeter 0.0.0.0

arp timeout 14400

nat 0 access-list 80

access-list 80 permit ip 10.0.0.0 255.0.0.0 192.168.12.0 255.255.255.0

no rip outside passive

no rip outside default

no rip inside passive

no rip inside default

no rip dmz passive

no rip dmz default

no rip perimeter passive

no rip perimeter default

route outside 0.0.0.0 0.0.0.0 209.165.200.228 1

timeout xlate 3:00:00 conn 1:00:00 half-closed 0:10:00 udp 0:02:00

timeout rpc 0:10:00 h323 0:05:00

timeout uauth 0:05:00 absolute

aaa-server TACACS+ protocol tacacs+

aaa-server RADIUS protocol radius

no snmp-server location

no snmp-server contact

snmp-server community public

no snmp-server enable traps

sysopt connection permit-ipsec

crypto ipsec transform-set strong esp-3des esp-sha-hmac

crypto map newyork 10 ipsec-isakmp

crypto map newyork 10 match address 80

crypto map newyork 10 set peer 209.165.201.8

crypto map newyork 10 set transform-set strong

crypto map newyork interface outside

isakmp policy 8 authentication rsa-sig

isakmp policy 8 encryption des

isakmp policy 8 hash sha

isakmp policy 8 group 1

isakmp policy 8 lifetime 86400

ca identity abcd 209.165.202.131 209.165.202.131

ca configure abcd ra 1 100 crloptional

telnet timeout 5

terminal width 80

Using an Encrypted Tunnel to Obtain Certificates

This section shows an example of how to perform CA enrollment and certificate requests via a site-to-site VPN tunnel between two PIX Firewall units (PIX Firewall 1 and 2). In the example, both PIX Firewall units enroll and request certificates from a CA server protected by PIX Firewall 1. PIX Firewall 2 enrolls and requests its certificate using an encrypted tunnel.

To accomplish this, you first establish a tunnel between the PIX Firewalls using a pre-shared key. You then use this tunnel to enroll and request the certificate for PIX Firewall 2. After obtaining a certificate, clear the IKE and IPSec SAs on both units and then configure them to use digital certificates.

---

Note The example CA server address is to be used for example purposes only.

---

This section includes the following topics:

•Establishing a Tunnel Using a Pre-Shared Key

•Establishing a Tunnel with a Certificate

This example uses the network diagram shown in Figure 7-4.

Figure 7-4 VPN Tunnel Network

Establishing a Tunnel Using a Pre-Shared Key

This section describes how to establish a tunnel using a pre-shared key. It includes the following topics:

•PIX Firewall 1 Configuration

•PIX Firewall 2 Configuration

PIX Firewall 1 Configuration

Follow these steps to configure PIX Firewall 1:

---

Step 1 Define a host name:

hostname NewYork

Step 2 Define the domain name:

domain-name example.com

Step 3 Configure an IKE policy:

isakmp enable outside

isakmp policy 8 auth pre-share

isakmp key cisco address 209.165.200.229 netmask 255.255.255.255

Step 4 Create a partial access list:

access-list 90 permit ip host 10.1.0.2 host 209.165.200.229

Step 5 Configure NAT 0:

nat (dmz) 0 access-list 90

Step 6 Configure a transform set that defines how the traffic will be protected:

crypto ipsec transform-set strong esp-3des esp-sha-hmac

Step 7 Define a crypto map:

crypto map toSanJose 20 ipsec-isakmp 

crypto map toSanJose 20 match address 90

crypto map toSanJose 20 set transform-set strong

crypto map toSanJose 20 set peer 209.165.200.229

Step 8 Apply the crypto map to the outside interface:

crypto map toSanJose interface outside

Step 9 Tell the PIX Firewall to implicitly permit IPSec traffic:

sysopt connection permit-ipsec

Step 10 Generate the PIX Firewall RSA key pair:

ca generate rsa key 512

This command is entered at the command line and does not get stored in the configuration.

Step 11 Define CA-related enrollment commands:

ca identity abcd 10.1.0.2:/certsrv/mscep/mscep.dll

ca configure abcd ra 1 20 crloptional

These commands are stored in the configuration.

---

Note The ca identity command shown is specific to the Microsoft CA. The ca identity you use depends on the CA you are using.

---

Step 12 Get the public key and the certificate of the CA server:

ca authenticate abcd

This command is entered at the command line and does not get stored in the configuration.

Step 13 Contact your CA administrator and send your certificate request:

ca enroll abcd cisco

The string "cisco" is a challenge password. This can be anything. This command is entered at the command line and does not get stored in the configuration.

Step 14 Save keys and certificates, and the ca commands (except those indicated) in Flash memory:

ca save all

write memory

---

Note Use the ca save all command any time you add, change, or delete ca commands in the configuration. This command is not stored in the configuration.

---

---

PIX Firewall 2 Configuration

Follow these steps to configure PIX Firewall 2:

---

Step 1 Define a host name:

hostname SanJose

Step 2 Define the domain name:

domain-name example.com

Step 3 Configure an IKE policy:

isakmp enable outside

isakmp policy 8 auth pre-share

isakmp key cisco address 209.165.201.8 netmask 255.255.255.255

Step 4 Create a partial access list:

access-list 80 permit ip host 209.165.200.229 host 10.1.0.2 

Step 5 Configure NAT 0:

nat (inside) 0 access-list 80

Step 6 Configure a transform set that defines how the traffic will be protected:

crypto ipsec transform-set strong esp-3des esp-sha-hmac

Step 7 Define a crypto map:

crypto map newyork 20 ipsec-isakmp 

crypto map newyork 20 match address 80

crypto map newyork 20 set transform-set strong

crypto map newyork 20 set peer 209.165.201.8

Step 8 Apply the crypto map to the outside interface:

crypto map newyork interface outside

Step 9 Tell the PIX Firewall to implicitly permit IPSec traffic:

sysopt connection permit-ipsec

Step 10 Generate the PIX Firewall RSA key pair:

ca generate rsa key 512

This command is entered at the command line and does not get stored in the configuration.

Step 11 Define CA-related enrollment commands:

ca identity abcd 10.1.0.2:/certsrv/mscep/mscep.dll

ca configure abcd ra 1 20 crloptional

These commands are stored in the configuration.

---

Note The ca identity command shown is specific to the Microsoft CA. The ca identity you use depends on the CA you are using.

---

Step 12 Authenticate the CA by obtaining its public key and its certificate:

ca authenticate abcd

This command is entered at the command line and does not get stored in the configuration.

Step 13 Request signed certificates from your CA for your PIX Firewall's RSA key pair. Before entering this command, contact your CA administrator because they will have to authenticate your PIX Firewall manually before granting its certificate:

ca enroll abcd cisco

"cisco" is a challenge password. This can be anything. This command is entered at the command line and does not get stored in the configuration.

Step 14 Save keys and certificates, and the CA commands (except those indicated) in Flash memory:

ca save all

write memory

---

Note Use the ca save all command any time you add, change, or delete ca commands in the configuration. This command is not stored in the configuration.

---

---

Establishing a Tunnel with a Certificate

This section describes how to clear the SAs on each PIX Firewall and to establish a tunnel using a certificate. It includes the following topics:

•PIX Firewall 1 Configuration

•PIX Firewall 2 Configuration

PIX Firewall 1 Configuration

Follow these steps to configure PIX Firewall 1:

---

Step 1 Clear the IPSec SAs:

clear ipsec sa

Step 2 Clear the ISAKMP SAs:

clear isakmp sa

Step 3 Create a partial access list:

access-list 90 permit ip 192.168.12.0 255.255.255.0 10.0.0.0 255.0.0.0 

Step 4 Configure NAT 0:

nat (inside) 0 access-list 90

Step 5 Specify the authentication method of rsa-signatures for the IKE policy:

isakmp policy 8 auth rsa-sig

---

PIX Firewall 2 Configuration

Follow these steps to configure PIX Firewall 2:

---

Step 1 Clear the IPSec SAs:

clear ipsec sa

Step 2 Clear the ISAKMP SAs:

clear isakmp sa

Step 3 Create a partial access list:

access-list 80 permit ip 10.0.0.0 255.0.0.0 192.168.12.0 255.255.255.0 

Step 4 Specify the authentication method of rsa-signatures for the IKE policy:

isakmp policy 8 auth rsa-sig

---

Connecting to a Catalyst 6500 and Cisco 7600 Series IPSec VPN Services Module

This section describes how to create an IPSec site-to-site tunnel between a Cisco Catalyst 6500 series switch with the Catalyst 6500 and Cisco 7600 Series IPSec VPN Services Module (VPNSM) and a PIX Firewall. It includes the following topics:

•Scenario Description

•Configuring IPSec Using a Trunk Port

•Configuring IPSec Using a Routed Port

•Verifying Your Configuration

Scenario Description

Figure 7-5 illustrates the network setup used in this example configuration.

Figure 7-5 VPN Tunnel Between PIX Firewall and Catalyst 6500 with VPNSM

The VPNSM has two Gigabit Ethernet (GE) ports with no externally visible connectors. These ports are addressable for configuration purposes only. Port 1 is always the inside port. This port handles all traffic from and to the inside network. The second port (port 2) handles all traffic from and to the WAN or outside networks. These two ports are always configured in 802.1q trunking mode.

Packets are processed by a pair of VLANs, one Layer 3 (L3) inside VLAN and one Layer 2 (L2) outside VLAN. The packets are routed to the inside VLAN. After encrypting the packets the VPNSM uses the corresponding outside VLAN. In the decryption process, the packets from the outside to the inside are bridged to the VPNSM using the outside VLAN. After the VPNSM decrypts the packet and maps the VLAN to the corresponding inside VLAN, EARL routes the packet to the appropriate LAN port. The L3 inside VLAN and the L2 VLANs are joined together by issuing the crypto connect vlan command. There are three types of ports in the Catalyst 6500 series switches:

•Routed Ports—By default all Ethernet ports are routed ports. These ports have a hidden VLAN associated with them.

•Access Ports—These ports have an external or VLAN Trunking Protocol (VTP) VLAN associated with them. You can associate more than one port to a defined VLAN.

•Trunk Ports—These ports carry many external or VTP VLANs, on which all packets are encapsulated with an 802.1q header.

Configuring IPSec Using a Trunk Port

Perform the following steps to configure an IPSec tunnel using the Catalyst 6500 trunk port configuration:

---

Step 1 Add the inside VLANs to the inside port of the VPNSM. Assuming that the VPNSM is on slot 3, use VLAN 100 as the inside VLAN and VLAN 200 as the outside, and configure the GE ports on the VPNSM as follows.

interface GigabitEthernet3/1 

no ip address 

switchport 

switchport trunk encapsulation dot1q 

switchport trunk allowed vlan 1,100,1002-1005 

switchport mode trunk 

interface GigabitEthernet3/2

no ip address

switchport

switchport trunk encapsulation dot1q

switchport trunk allowed vlan 1,200,1002-1005

switchport mode trunk

Step 2 Add the VLAN 100 interface and the interface where the tunnel will be terminated (in this case, FastEthernet2/2):

interface Vlan100

ip address 209.165.201.1 255.255.255.0

interface FastEthernet2/2

no ip address

switchport

switchport access vlan 200

switchport mode access

crypto connect vlan 100

Step 3 Create an ACL (in this case, ACL 100) defining the traffic from the inside network 10.10.10.0/24 to the remote network 10.20.20.0/24:

access-list 100 permit ip 10.10.10.0 0.0.0.255 10.20.20.0 0.0.0.255

Step 4 Define your Internet Security Association and Key Management Protocol (ISAKMP) policy proposals:

crypto isakmp policy 1

hash md5

authentication pre-share

group 2

Step 5 In this example, pre-shared keys are used and defined by issuing the following command:

crypto isakmp key cisco address 209.165.200.225

Step 6 Define your IPSec proposals:

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

Step 7 Create your crypto map statement:

crypto map cisco 10 ipsec-isakmp

set peer 209.165.200.225

set transform-set cisco

match address 100

Step 8 Apply the crypto map to the VLAN 100 interface:

interface vlan100

crypto map cisco

---

Example 7-7 shows the complete configuration for the VPNSM.

Example 7-7 VPNSM Configuration

!--- Define Phase 1 policy. 

crypto isakmp policy 1

hash md5

authentication pre-share

group 2

crypto isakmp key cisco address 209.165.200.225

!

!

!--- Define the encryption policy for this setup. 

crypto ipsec transform-set cisco ESP-Des esp-md5-hmac

!

!--- Define a static crypto map entry for the peer 

!--- with mode ipsec-isakmp. 

!--- This indicates that Internet Key Exchange (IKE) 

!--- will be used to establish the IPSec 

!--- Security Associations (SAs) for protecting the traffic 

!--- specified by this crypto map entry. 

crypto map cisco 10 ipsec-isakmp

set peer 209.165.200.225

set transform-set cisco

match address 100

!

!

no spanning-tree vlan 100

!

!

!

interface GigabitEthernet1/1

no ip address

shutdown

snmp trap link-status

switchport

!

interface GigabitEthernet1/2

no ip address

shutdown

!

interface FastEthernet2/1

ip address 10.10.10.1 255.255.255.0

no keepalive

!

!--- This is the secure port which is configured in routed port mode. 

!--- This routed port mode purposely does not have an L3 IP address 

!--- configured, which is normal for the BITW process. 

!--- The IP address was moved from this interface to the VLAN 100 to

!--- accomplish BITW, thereby bringing the VPN Services Module into

!--- the packet path. This will be the L2 port VLAN on which the

!--- VPN Services Module's outside port also belongs. 

interface FastEthernet2/2

no ip address

snmp trap link-status

switchport

switchport access vlan 200

switchport mode access

crypto connect vlan 100

!

interface GigabitEthernet3/1

no ip address

snmp trap link-status

switchport

switchport trunk encapsulation dot1q

!--- VLAN 100 is defined as the Interface VLAN (IVLAN).

switchport trunk allowed vlan 1,100,1002-1005

switchport mode trunk

flowcontrol receive on

cdp enable

!

interface GigabitEthernet3/2

no ip address

snmp trap link-status

switchport

switchport trunk encapsulation dot1q

!--- The Port VLAN (PVLAN) configuration is handled by the VPN Services Module

!--- transparently without user configuration

!--- or involvement. It also is not shown in the configuration.

!--- Note that for every IVLAN a corresponding PVLAN exists. 

switchport trunk allowed vlan 1,200,1002-1005

switchport mode trunk

flowcontrol receive on

cdp enable

!

interface Vlan1

no ip address

shutdown

!

!--- This is the IVLAN configured for intercepting the traffic 

!--- destined to the secure port on which the VPN Services Module's inside port 

!--- is the only port present. 

Interface Vlan100

ip address 209.165.201.1 255.255.255.0

crypto map cisco

!

interface Vlan200

no ip address

!

ip classless

!--- Configure the routing so that the device

!--- knows how to reach its destination network. 

ip route 0.0.0.0 0.0.0.0 172.18.124.1

!

!--- This is the crypto ACL. 

access-list 100 permit ip 10.10.10.0 0.0.0.255 10.20.20.0 0.0.0.255

Example 7-8 shows the complete configuration for the PIX Firewall.

Example 7-8 PIX Firewall Configuration

nameif ethernet0 outside security0

nameif ethernet1 inside security100

nameif ethernet2 intf2 security10

nameif ethernet3 intf3 security15

nameif ethernet4 intf4 security20

nameif ethernet5 intf5 security25

enable password 8Ry2YjIyt7RRXU24 encrypted

passwd 2KFQnbNIdI.2KYOU encrypted

hostname pix515B

domain-name cisco.com

fixup protocol ftp 21

fixup protocol http 80

fixup protocol h323 h225 1720

fixup protocol h323 ras 1718-1719

fixup protocol ils 389

fixup protocol rsh 514

fixup protocol rtsp 554

fixup protocol smtp 25

fixup protocol sqlnet 1521

fixup protocol sip 5060

fixup protocol skinny 2000

names

!--- Traffic to the router.

Access-list 100 permit ip 10.20.20.0 255.255.255.0 10.10.10.0 255.255.255.0

pager lines 24

interface ethernet0 auto

interface ethernet1 auto

interface ethernet2 auto shutdown

interface ethernet3 auto shutdown

interface ethernet4 auto shutdown

interface ethernet5 auto shutdown

mtu outside 1500

mtu inside 1500

mtu intf2 1500

mtu intf3 1500

mtu intf4 1500

mtu intf5 1500

ip address outside 209.165.200.225 255.255.255.0

ip address inside 10.20.20.1 255.255.255.0

ip address intf2 127.0.0.1 255.255.255.255

ip address intf3 127.0.0.1 255.255.255.255

ip address intf4 127.0.0.1 255.255.255.255

ip address intf5 127.0.0.1 255.255.255.255

ip audit info action alarm

ip audit attack action alarm

no failover

failover timeout 0:00:00

failover poll 15

failover ip address outside 0.0.0.0

failover ip address inside 0.0.0.0

failover ip address intf2 0.0.0.0

failover ip address intf3 0.0.0.0

failover ip address intf4 0.0.0.0

failover ip address intf5 0.0.0.0

pdm history enable

arp timeout 14400

access-list host1 permit icmp any any

access-group host1 in interface outside

route outside 0.0.0.0 0.0.0.0 14.36.1.1 1

timeout xlate 3:00:00

timeout conn 1:00:00 half-closed 0:10:00 udp 0:02:00 rpc 0:10:00 h323

   0:05:00 sip 0:30:00 sip_media 0:02:00

timeout uauth 0:05:00 absolute

aaa-server TACACS+ protocol tacacs+

AAA-server RADIUS protocol radius

AAA-server LOCAL protocol local

no snmp-server location

no snmp-server contact

snmp-server community public

no snmp-server enable traps

floodguard enable

!--- IPSec policies.

sysopt connection permit-ipsec

no sysopt route dnat

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

crypto map cisco 10 ipsec-isakmp

crypto map cisco 10 match address 100

crypto map cisco 10 set peer 209.165.201.1

crypto map cisco 10 set transform-set cisco

crypto map cisco interface outside

!--- IKE policies.

isakmp enable outside

isakmp key ******** address 209.165.201.1 netmask 255.255.255.255

isakmp policy 1 authentication pre-share

isakmp policy 1 encryption des

isakmp policy 1 hash md5

isakmp policy 1 group 2

isakmp policy 1 lifetime 86400

telnet timeout 5

ssh timeout 5

terminal width 80

Cryptochecksum:02a61666fbc808eaf2ba99b69d544df7

: end

[OK]

Configuring IPSec Using a Routed Port

Perform the following steps to configure IPSec using the routed port configuration on the Catalyst 6500 VPN Services Module.

---

Step 1 Add the inside VLANs to the inside port of the VPNSM. Assuming that the VPNSM is on slot 3, use VLAN 100 as the inside VLAN and VLAN 200 as the outside, and configure the GE ports on the VPNSM as follows.

interface GigabitEthernet3/1 

no ip address 

switchport 

switchport trunk encapsulation dot1q 

switchport trunk allowed vlan 1,100,1002-1005 

switchport mode trunk 

interface GigabitEthernet3/2

no ip address

switchport

switchport trunk encapsulation dot1q

switchport trunk allowed vlan 1,200,1002-1005

switchport mode trunk

Step 2 Add the VLAN 100 interface, and the interface where the tunnel will be terminated (in this case, FastEthernet2/2):

interface Vlan100

ip address 209.165.201.1 255.255.255.0

interface FastEthernet2/2

no ip address

crypto connect vlan 100

Step 3 Create an ACL (in this case, ACL 100) defining the traffic from the inside network 10.10.10.0/24 to the remote network 10.20.20.0/24:

access-list 100 permit ip 10.10.10.0 0.0.0.255 10.20.20.0 0.0.0.255

Step 4 Define your ISAKMP policy proposals:

crypto isakmp policy 1

hash md5

authentication pre-share

group 2

Step 5 In this example, pre-shared keys are used and defined by issuing the following command:

crypto isakmp key cisco address 209.165.200.225

Step 6 Define your IPSec proposals:

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

Create your crypto map statement.

crypto map cisco 10 ipsec-isakmp

 set peer 209.165.200.225

 set transform-set cisco

 match address 100

Step 7 Apply the crypto map to the VLAN 100 interface:

interface vlan100

crypto map cisco

---

Example 7-9 shows the complete configuration for the VPNSM.

Example 7-9 Catalyst 6500 Configuration

!--- Define Phase 1 policy. 

crypto isakmp policy 1

hash md5

authentication pre-share

group 2

crypto isakmp key cisco address 209.165.200.225

!

!

!--- Define the encryption policy for this setup. 

crypto ipsec transform-set cisco ESP-Des esp-md5-hmac

!

!--- Define a static crypto map entry for the peer 

!--- with mode ipsec-isakmp. This indicates that IKE 

!--- will be used to establish the IPSec 

!--- SAs for protecting the traffic 

!--- specified by this crypto map entry. 

crypto map cisco 10 ipsec-isakmp

set peer 209.165.200.225

set transform-set cisco

match address 100

!

!

no spanning-tree vlan 100

!

!

!

interface GigabitEthernet1/1

no ip address

shutdown

snmp trap link-status

switchport

!

interface GigabitEthernet1/2

no ip address

shutdown

!

interface FastEthernet2/1

ip address 10.10.10.1 255.255.255.0

no keepalive

!

!--- This is the secure port which is configured in routed port mode. 

!--- This routed port mode does not have an L3 IP address 

!--- configured, which is normal for the BITW process. 

!--- The IP address was moved from this interface to the VLAN 100 to

!--- accomplish BITW, thereby bringing the VPN Services Module into

!--- the packet path. This will be the L2 port VLAN on which the

!--- VPN Services Module's outside port also belongs.

Interface FastEthernet2/2

no ip address

crypto connect vlan 100

!

interface GigabitEthernet3/1

no ip address

snmp trap link-status

switchport

switchport trunk encapsulation dot1q

!--- VLAN 100 is defined as the IVLAN.

switchport trunk allowed vlan 1,100,1002-1005

switchport mode trunk

flowcontrol receive on

cdp enable

!

interface GigabitEthernet3/2

no ip address

snmp trap link-status

switchport

switchport trunk encapsulation dot1q

!--- The PVLAN configuration is handled by the VPN Services Module

!--- transparently without user configuration

!--- or involvement. It also is not shown in the configuration.

!--- Note that for every IVLAN a corresponding PVLAN exists. 

switchport trunk allowed vlan 1,200,1002-1005

switchport mode trunk

flowcontrol receive on

cdp enable

!

interface Vlan1

no ip address

shutdown

!

!--- This is the IVLAN configured for intercepting the traffic 

!--- destined to the secure port on which the VPN Services Module's inside port 

!--- is the only port present. 

Interface Vlan100

ip address 209.165.201.1 255.255.255.0

crypto map cisco

!

interface Vlan200

no ip address

!

ip classless

!--- Configure the routing so that the device

!--- knows how to reach its destination network. 

ip route 0.0.0.0 0.0.0.0 172.18.124.1

ip route 10.20.20.0 255.255.255.0 209.165.200.225

!

!--- This is the crypto ACL.

Access-list 100 permit ip 10.10.10.0 0.0.0.255 10.20.20.0 0.0.0.255

Example 7-10 shows the complete configuration for the PIX Firewall.

Example 7-10 PIX Firewall Configuration

nameif ethernet0 outside security0

nameif ethernet1 inside security100

nameif ethernet2 intf2 security10

nameif ethernet3 intf3 security15

nameif ethernet4 intf4 security20

nameif ethernet5 intf5 security25

enable password 8Ry2YjIyt7RRXU24 encrypted

passwd 2KFQnbNIdI.2KYOU encrypted

hostname pix515B

domain-name cisco.com

fixup protocol ftp 21

fixup protocol http 80

fixup protocol h323 h225 1720

fixup protocol h323 ras 1718-1719

fixup protocol ils 389

fixup protocol rsh 514

fixup protocol rtsp 554

fixup protocol smtp 25

fixup protocol sqlnet 1521

fixup protocol sip 5060

fixup protocol skinny 2000

names

!--- Traffic to the router.

Access-list 100 permit ip 10.20.20.0 255.255.255.0 10.10.10.0 255.255.255.0

pager lines 24

interface ethernet0 auto

interface ethernet1 auto

interface ethernet2 auto shutdown

interface ethernet3 auto shutdown

interface ethernet4 auto shutdown

interface ethernet5 auto shutdown

mtu outside 1500

mtu inside 1500

mtu intf2 1500

mtu intf3 1500

mtu intf4 1500

mtu intf5 1500

ip address outside 209.165.200.225 255.255.255.0

ip address inside 10.20.20.1 255.255.255.0

ip address intf2 127.0.0.1 255.255.255.255

ip address intf3 127.0.0.1 255.255.255.255

ip address intf4 127.0.0.1 255.255.255.255

ip address intf5 127.0.0.1 255.255.255.255

ip audit info action alarm

ip audit attack action alarm

no failover

failover timeout 0:00:00

failover poll 15

failover ip address outside 0.0.0.0

failover ip address inside 0.0.0.0

failover ip address intf2 0.0.0.0

failover ip address intf3 0.0.0.0

failover ip address intf4 0.0.0.0

failover ip address intf5 0.0.0.0

pdm history enable

arp timeout 14400

access-list host1 permit icmp any any

access-group host1 in interface outside

route outside 0.0.0.0 0.0.0.0 14.36.1.1 1

timeout xlate 3:00:00

timeout conn 1:00:00 half-closed 0:10:00 udp 0:02:00 rpc 0:10:00 h323

    0:05:00 sip 0:30:00 sip_media 0:02:00

timeout uauth 0:05:00 absolute

AAA-server TACACS+ protocol tacacs+

AAA-server RADIUS protocol radius

AAA-server LOCAL protocol local

no snmp-server location

no snmp-server contact

snmp-server community public

no snmp-server enable traps

floodguard enable

!--- IPSec policies.

sysopt connection permit-ipsec

no sysopt route dnat

crypto ipsec transform-set cisco ESP-Des esp-md5-hmac

crypto map cisco 10 ipsec-isakmp

crypto map cisco 10 match address 100

crypto map cisco 10 set peer 209.165.201.1

crypto map cisco 10 set transform-set cisco

crypto map cisco interface outside

!--- IKE policies.

isakmp enable outside

isakmp key ******** address 209.165.201.1 netmask 255.255.255.255

isakmp policy 1 authentication pre-share

isakmp policy 1 encryption Des

isakmp policy 1 hash md5

isakmp policy 1 group 2

isakmp policy 1 lifetime 86400

telnet timeout 5

ssh timeout 5

terminal width 80

Cryptochecksum:02a61666fbc808eaf2ba99b69d544df7

: end

[OK]

Verifying Your Configuration

You can use the following commands to confirm that your configuration is working properly.

To display the settings used by the current IPSec SAs, enter the following command:

show crypto ipsec sa

To display all the current IKE SAs at a peer, enter the following command:

show crypto isakmp sa

To display the VLAN associated with the crypto configuration, enter the following command:

show crypto vlan 

To display the VPNSM statistics, enter the following command:

show crypto eli

Manual Configuration with NAT

In this example, two PIX Firewall units are used to create a Virtual Private Network (VPN) between the networks on each PIX Firewall unit's inside interface. This section includes the following topics:

•PIX Firewall 1 Configuration

•PIX Firewall 2 Configuration

This network is part of an intranet. In this example, the VPN is created without the use of IKE or a CA and pre-shared keys are used.

PIX Firewall 1 Configuration

Follow these steps to program the PIX Firewall 1 unit for IPSec:

---

Step 1 Create a crypto map command statement.

Step 2 Create the access-list command entries to select traffic for this policy.

---

Note For manual keying, only one access-list permit command statement is permitted in the configuration.

---

Step 3 Create the transform set for the crypto command statement entry.

Step 4 Define cryptographic state informations. These include SPI, and the necessary keys for manual keying and policy negotiation for ISAKMP.

Step 5 Repeat Steps 1-4 for each group of policies.

Step 6 Associate the crypto map command statement with an interface.

---

Example 7-11 lists the configuration for PIX Firewall 1.

Example 7-11 Two Interfaces with IPSec—PIX Firewall 1 Configuration

nameif ethernet0 outside security0

nameif ethernet1 inside security100

interface ethernet0 auto

interface ethernet1 auto

ip address outside 192.168.1.1 255.255.255.0

ip address inside 10.1.1.1 255.255.255.0

enable password 8Ry2YjIyt7RRXU24 encrypted

passwd 2KFQnbNIdI.2KYOU encrypted

hostname pixfirewall

fixup protocol ftp 21

fixup protocol http 80

fixup protocol smtp 25

fixup protocol h323 1720

fixup protocol rsh 514

fixup protocol sqlnet 1521

access-list 10 permit ip host 192.168.128.3 host 209.165.200.225

no failover

failover ip address outside 0.0.0.0

failover ip address inside 0.0.0.0

names

pager lines 24

no logging timestamp

logging console debugging

logging monitor errors

logging buffered errors

no logging trap 

logging facility 20

mtu outside 1500

mtu inside 1500

arp timeout 14400

nat (inside) 1 0 0

global (outside) 1 192.168.1.100-192.168.1.150

static (inside,outside) 192.168.128.3 10.1.1.3 netmask 255.255.255.255 0 0

no rip outside passive

no rip outside default

no rip inside passive

no rip inside default

route outside 0.0.0.0 0.0.0.0 192.168.1.49 1

timeout xlate 3:00:00 conn 1:00:00 half-closed 0:10:00 udp 0:02:00

timeout rpc 0:10:00 h323 0:05:00

timeout uauth 0:05:00 absolute

no snmp-server location

no snmp-server contact

snmp-server community public

no snmp-server enable traps

sysopt connection tcpmss 1380

sysopt connection permit-ipsec

crypto ipsec transform-set myset ah-md5-hmac esp-des

crypto map mymap 10 ipsec-manual

crypto map mymap 10 match address 10

crypto map mymap 10 set peer 192.168.1.100 

crypto map mymap 10 set transform-set myset

crypto map mymap 10 set session-key inbound ah 400 123456789A123456789A123456789A12

crypto map mymap 10 set session-key outbound ah 300 123456789A123456789A123456789A12

crypto map mymap 10 set session-key inbound esp 400 cipher abcd1234abcd1234 

crypto map mymap 10 set session-key outbound esp 300 cipher abcd1234abcd1234 

telnet timeout 5

terminal width 80

crypto map mymap interface outside

PIX Firewall 2 Configuration

Follow these steps to program the PIX Firewall 2 unit for IPSec:

---

Step 1 Create a crypto map command statement.

Step 2 Create the access-list command entries to select traffic for this policy.

---

Note For manual keying, only one access-list permit command statement is permitted in the configuration.

---

Step 3 Create the transform set for the crypto command statement entry.

Step 4 Define cryptographic state informations. These include SPI, and the necessary keys for manual keying and policy negotiation for ISAKMP.

Step 5 Repeat Steps 1-4 for each group of policies.

Step 6 Associate the crypto map command statement with an interface.

---

Example 7-12 lists the configuration for PIX Firewall 2.

Example 7-12 Two Interfaces with IPSec—PIX Firewall 2 Configuration

nameif ethernet0 outside security0

nameif ethernet1 inside security100

interface ethernet0 auto

interface ethernet1 auto

ip address outside 209.165.201.3 255.255.255.224

ip address inside 10.0.0.3 255.255.255.0

enable password 8Ry2YjIyt7RRXU24 encrypted

passwd 2KFQnbNIdI.2KYOU encrypted

hostname pixfirewall

fixup protocol ftp 21

fixup protocol http 80

fixup protocol smtp 25

fixup protocol h323 1720

fixup protocol rsh 514

fixup protocol sqlnet 1521

access-list 10 permit ip host 209.165.200.225 host 192.168.128.3

no failover

failover ip address outside 0.0.0.0

failover ip address inside 0.0.0.0

names

pager lines 24

no logging timestamp

logging console debugging

logging monitor errors

logging buffered errors

no logging trap

logging facility 20

mtu outside 1500

mtu inside 1500

arp timeout 14400

nat (inside) 1 0 0

static (inside,outside) 209.165.200.225 10.0.0.3 netmask 255.255.255.255 0 0

route outside 0.0.0.0 0.0.0.0 192.168.1.49 1

route inside 10.0.0.0 255.255.255.0 10.0.0.3 1

timeout xlate 3:00:00 conn 1:00:00 half-closed 0:10:00 udp 0:02:00

timeout rpc 0:10:00 h323 0:05:00

timeout uauth 0:05:00 absolute

no snmp-server location

no snmp-server contact

snmp-server community public

no snmp-server enable traps

no rip outside passive

no rip outside default

no rip inside passive

no rip inside default

sysopt connection tcpmss 1380

crypto ipsec transform-set myset ah-md5-hmac esp-des

crypto map mymap 10 ipsec-manual

crypto map mymap 10 match address 10

crypto map mymap 10 set peer 192.168.1.1 

crypto map mymap 10 set transform-set myset

crypto map mymap 10 set session-key inbound ah 300 123456789A123456789A123456789A12

crypto map mymap 10 set session-key outbound ah 400 123456789A123456789A123456789A12

crypto map mymap 10 set session-key inbound esp 300 cipher abcd1234abcd1234 

crypto map mymap 10 set session-key outbound esp 400 cipher abcd1234abcd1234 

telnet timeout 5

terminal width 80