Product Documentation

Configuring a CloudBridge Connector tunnel between a Citrix ADC appliance and Cisco IOS device

You can configure a CloudBridge Connector tunnel between a Citrix ADC appliance and a Cisco device to connect two datacenters or extend your network to a Cloud provider. The Citrix ADC appliance and the Cisco IOS device form the end points of the CloudBridge Connector tunnel and are called peers.

Example of CloudBridge Connector tunnel configuration and data flow

As an illustration of the traffic flow in a CloudBridge Connector tunnel, consider an example in which a CloudBridge Connector tunnel is set up between the following devices:

  • Citrix ADC appliance NS_Appliance-1 in a datacenter designated as Datacenter-1
  • Cisco IOS device Cisco-IOS-Device-1 in a datacenter designated as Datacenter-2

NS_Appliance-1 and Cisco-IOS-Device-1 enable communication between private networks in Datacenter-1 and Datacenter-2 through the CloudBridge Connector tunnel. In the example, NS_Appliance-1 and Cisco-IOS-Device-1 enable communication between client CL1 in Datacenter-1 and server S1 in Datacenter-2 through the CloudBridge Connector tunnel. Client CL1 and server S1 are on different private networks.

On NS_Appliance-1, the CloudBridge Connector tunnel configuration includes IPSec profile entity NS_Cisco_IPSec_Profile, CloudBridge Connector tunnel entity NS_Cisco_Tunnel, and policy based routing (PBR) entity NS_Cisco_Pbr.

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For more information, refer to the CloudBridge Connector tunnel between a Citrix ADC appliance and Cisco IOS device settings pdf.

Points to Consider for a CloudBridge Connector tunnel configuration

Before configuring a CloudBridge Connector tunnel between a Citrix ADC appliance and a Cisco IOS device, consider the following points:

  • The following IPSec settings are supported for a CloudBridge Connector tunnel between a Citrix ADC appliance and a Cisco IOS device.
IPSec Properties Setting
IPSec mode Tunnel mode
IKE version Version 1
IKE authentication method Pre-Shared Key
IKE encryption algorithm AES, 3DES
IKE hash algorithm HMAC SHA1, HMAC SHA256, HMAC SHA384, HMAC SHA512, HMAC MD5
ESP encryption algorithm AES, 3DES
ESP hash algorithm HMAC SHA1, HMAC SHA256, HMAC SHA256, HMAC SHA256, HMAC MD5
  • You must specify the same IPSec settings on the Citrix ADC appliance and the Cisco IOS device at the two ends of the CloudBridge Connector.
  • Citrix ADC provides a common parameter (in IPSec profiles) for specifying an IKE hash algorithm and an ESP hash algorithm. It also provides another, and a common parameter for specifying an IKE encryption algorithm and an ESP encryption algorithm.  Therefore on the Cisco device, you must specify the same hash algorithm and same encryption algorithm for IKE (while creating IKE policy) and ESP (while creating IPSec transform set).
  • You must configure the firewall at the Citrix ADC end and Cisco device end to allow the following.
    • Any UDP packets for port 500
    • Any UDP packets for port 4500
    • Any ESP (IP protocol number 50) packets

Configuring Cisco IOS device for the CloudBridge Connector tunnel

To configure a CloudBridge Connector tunnel on a Cisco IOS device, use the Cisco IOS command line interface, which is the primary user interface for configuring, monitoring, and maintaining Cisco devices.

Before you begin the CloudBridge Connector tunnel configuration on a Cisco IOS device, make sure that:

  • You have a user account with administrator credentials on the Cisco IOS device.
  • You are familiar with the Cisco IOS command line interface.
  • The Cisco IOS device is UP and running, is connected to the Internet, and is also connected to the private subnets whose traffic is to be protected over the CloudBridge Connector tunnel.

Note:

The procedures for configuring CloudBridge Connector tunnel on a Cisco IOS device might change over time, depending on the Cisco release cycle. Citrix recommends that you follow the official Cisco product documention for more information, see Configuring IPSec VPN tunnels topic.

To configure a CloudBridge connector tunnel between a Citrix ADC appliance and a Cisco IOS device, perform the following tasks on the Cisco device’s IOS command line:

  • Create an IKE Policy. An IKE policy defines a combination of security parameters to be used during the IKE negotiation. For example, parameters such as hash algorithm, encryption algorithm, Diffie-Hellman group, and authentication method to be used in the IKE negotiation are set in this task.
  • Configure a Pre-shared key for IKE authentication. A pre-shared key is a text string, which the peers of a CloudBridge Connector tunnel use to mutually authenticate with each other.  The pre-shared keys are matched against each other for IKE authentication. Therefore, for the authentication to be successful, you must configure the same pre-shared key on the Cisco device and the Citrix ADC appliance.
  • Define a transform set and configure IPSec in tunnel mode. A transform set defines a combination of security parameters to be used in the exchange of data over the CloudBridge Connector tunnel after the IKE negotiation is successful.  Parameters such as hash algorithm and encryption algorithm are set in this task. This task also specifies that IPSec in tunnel mode be used for the CloudBridge tunnel.
  • Create a crypto access List. Crypto access lists are used to define the subnets whose IP traffic will be protected over the CloudBridge tunnel. The source and destination parameters in the access list specify the Cisco device side and Citrix ADC side subnets that are to be protected over the CloudBridge Connector Tunnel. The access list must be set to permit. Any request packet that originates from a device in the Cisco device side subnet and is destined to a device in the Citrix ADC side subnet, and that matches the source and destination parameters of the access list, is sent across the CloudBridge Connector tunnel.
  • Create a crypto map. Crypto maps define the IPSec parameters to be negotiated with peer. They include the following: Crypto access list to identify the subnets whose traffic is to be protected over the CloudBridge tunnel, peer (Citrix ADC) identification by IP address, and transform set to match the peer security settings.
  • Apply the crypto Map to an interface. In this task, you apply a crypto map to an interface through which CloudBridge Connector tunnel traffic will flow. Applying the crypto map to an interface instructs the Cisco IOS device to evaluate all the interface traffic against the crypto map set, and to use the specified policy during connection or SA negotiation on behalf of subnet’s traffic to be protected.

The examples in the following procedures create settings of Cisco IOS device Cisco-IOS-Device-1 used in “Example of CloudBridge Connector Configuration and Data Flow.”

To create an IKE policy, refer to the IKE policy pdf.

To configure a pre-shared key by using the Cisco IOS command line

At the Cisco IOS device’s command prompt, type the following commands, starting in global configuration mode, in the order shown:

Command Example Command Description
crypto isakmp identity address Cisco-ios-device-1(config)# crypto isakmp identity address Specify the ISAKMP identity (address) for the Cisco IOS device to use when communicating with the peer (Citrix ADC appliance) during IKE negotiations. This example specifies the address keyword, which uses IP address 203.0.113.200 (Gigabit Ethernet interface 0/1 of Cisco-IOS-Device-1) as the identity for the device.
crypto isakmp key keystringaddress peer-address Cisco-ios-device-1 (config)# crypto isakmp key examplepresharedkey address 198.51.100.100 Specify a pre-shared key for the IKE authentication. This example configures shared key examplepresharedkey to be used with the Citrix ADC appliance NS_Appliance-1 (198.51.100.100). The same pre-shared key must be configured on the Citrix ADC appliance for IKE authentication to be successful between the Cisco IOS device and the Citrix ADC appliance.

To create a crypto access list by using the Cisco IOS command line

At the Cisco IOS device’s command prompt, type the following command in global configuration mode, in the order shown:

Command Example Command Description
access-listaccess-list-number permit IPsource source-wildcard destination destination-wildcard Cisco-ios-device-1(config)# access-list 111 permit ip 10.20.20.0 0.0.0.255 10.102.147.0 0.0.0.255 Specify conditions to determine the subnets whose IP traffic is to be protected over the CloudBridge Connector tunnel. This example configures access list 111 to protect traffic from subnets 10.20.20.0/24 (at the Cisco-IOS-Device-1 side) and 10.102.147.0/24 (at the NS_Appliance-1 side).

To define a transform and configure IPSec tunnel mode by using the Cisco IOS command line

At the Cisco IOS device’s command prompt, type the following commands, starting in global configuration mode, in the order shown: |Command|Example|Command Description| |–|–|–| |crypto ipsec transform-setname ESP_Authentication _Transform ESP_Encryption_Transform Note: ESP_Authentication _Transform can take the following values:

esp-sha-hmac esp-sha256-hmac esp-sha384-hmac esp-sha512-hmac esp-md5-hmac

ESP_Encryption_Transformcan take the following values:

esp-aes esp-3des|Cisco-ios-device-1(config)# crypto ipsec transform-set NS-CISCO-TS esp-sha256-hmac esp-3des|Define a transform set and specify the ESP hash algorithm (for authentication) and the ESP encryption algorithm to be used during exchange of data between the CloudBridge Connector tunnel peers. This example defines transform set NS-CISCO-TS and specifies ESP authentication algorithm as esp-sha256-hmac, and ESP encryption algorithm as esp-3des.| |mode tunnel|Cisco-ios-device-1 (config-crypto-trans)# mode tunnel|Set IPSec in tunnel mode.| |exit|Cisco-ios-device-1 (config-crypto-trans)# exit, Cisco-ios-device-1 (config)#|Exit back to global configuration mode.|

To create a crypto map by using the Cisco IOS command line

At the Cisco IOS device’s command prompt, type the following commands starting in global configuration mode, in the order shown:

Command Example Command Description
crypto mapmap-name seq-num ipsec-isakmp Cisco-ios-device-1 (config)# crypto map NS-CISCO-CM 2 ipsec-isakmp Enter crypto map configuration mode, specify a sequence number for the crypto map, and configure the crypto map to use IKE to establish security associations (SAs). This example configures sequence number 2 and IKE for crypto map NS-CISCO-CM.
set peer ip-address Cisco-ios-device-1 (config-crypto-map)# set peer 172.23.2.7 Specify the peer (Citrix ADC appliance) by its IP address. This example specifies 198.51.100.100, which is the CloudBridge Connector endpoint IP address on the Citrix ADC appliance.
match addressaccess-list-id Cisco-ios-device-1 (config-crypto-map)# match address 111 Specify an extended access list. This access list specifies conditions to determine the subnets whose IP traffic is to be protected over the CloudBridge Connector tunnel. This example specifies access list 111.
set transform-set transform-set-name Cisco-ios-device-1 (config-crypto-map)# set transform-set NS-CISCO-TS Specify which transform sets are allowed for this crypto map entry. This example specifies transform set NS-CISCO-TS.
exit Cisco-ios-device-1 (config-crypto-map)# exit  
Cisco-ios-device-1 (config)# Exit back to global configuration mode.  

To apply a crypto map to an interface by using the Cisco IOS command line

At the Cisco IOS device’s command prompt, type the following commands starting in global configuration mode, in the order shown:

Command Example Command Description
interfaceinterface-ID Cisco-ios-device-1(config)# interface GigabitEthernet 0/1 Specify a physical interface to which to apply the crypto map and enter interface configuration mode. This example specifies Gigabit Ethernet interface 0/1 of the Cisco device Cisco-IOS-Device-1. IP address 203.0.113.200 is already set to this interface.
crypto mapmap-name Cisco-ios-device-1 (config-if)# crypto map NS-CISCO-CM Apply the crypto map to the physical interface. This example applies crypto map NS-CISCO-CM.
exit Cisco-ios-device-1 (config-if)# exit, Cisco-ios-device-1 (config)# Exit back to global configuration mode.

Configuring the Citrix ADC appliance for the CloudBridge Connector tunnel

To configure a CloudBridge Connector tunnel between a Citrix ADC appliance and a Cisco IOS device, perform the following tasks on the Citrix ADC appliance. You can use either the Citrix ADC command line or the Citrix ADC graphical user interface (GUI):

  • Create an IPSec profile. An IPSec profile entity specifies the IPSec protocol parameters, such as IKE version, encryption algorithm, hash algorithm, and authentication method (Pre-Shared key) to be used by the IPSec protocol in the CloudBridge Connector tunnel.
  • Create an IP tunnel that uses IPSec protocol, and associate the IPSec profile with it. An IP tunnel specifies the local IP address (CloudBridge Connector tunnel end point IP address (of type SNIP) configured on the Citrix ADC appliance), remote IP address (CloudBridge Connector tunnel endpoint IP address configured on the Cisco IOS device), protocol (IPSec) used to set up the CloudBridge Connector tunnel, and an IPSec profile entity. The created IP tunnel entity is also called the CloudBridge Connector tunnel entity.
  • Create a PBR rule and associate it with the IP tunnel. A PBR entity specifies a set of rules and an IP tunnel (CloudBridge Connector tunnel) entity. The source IP address range and the destination IP address range are the conditions for the PBR entity. Set the source IP address range to specify the Citrix ADC-side subnet whose traffic is to be protected over the tunnel, and set the destination IP address range to specify the Cisco IOS device side subnet whose traffic is to be protected over the tunnel. Any request packet that originates from a client in the subnet on the Citrix ADC side and is destined to a server in the Cisco IOS device side subnet, and matches the source and destination IP range of the PBR entity, is sent across the CloudBridge Connector tunnel associated with the PBR entity. Apply the PBR rule to make it functional.

To create an IPSEC profile by using the Citrix ADC command line

At the Command prompt, type:

  • add ipsec profile <name> -psk <string> -ikeVersion v1
  • show ipsec profile <name>

To create an IPSEC tunnel and bind the IPSEC profile to it by using the Citrix ADC command line

At the Command prompt, type:

  • add ipTunnel <name> <remote> <remoteSubnetMask> <local> -protocol IPSEC –ipsecProfileName <string>
  • add ipTunnel <name>

To create a PBR rule and bind the IPSEC tunnel to it by using the Citrix ADC command line

At the Command prompt, type:

  • add pbr <pbrName> ALLOW –srcIP <subnet-range> -destIP <subnet-range> -ipTunnel <tunnelName>
  • apply pbrs
  • show pbrs <pbrName>

The following commands create settings of Citrix ADC appliance NS_Appliance-1 in “Example of CloudBridge Connector Configuration and Data Flow.”

    >  add ipsec profile NS_Cisco_IPSec_Profile -psk  examplepresharedkey -ikeVersion v1 –lifetime 315360 –encAlgo 3DES
    Done
    >  add iptunnel NS_Cisco_Tunnel 203.0.113.200 255.255.255.255 198.51.100.100 –protocol IPSEC –ipsecProfileName NS_Cisco_IPSec_Profile  

    Done
    > add pbr NS_Cisco_Pbr -srcIP 10.102.147.0-10.102.147.255 –destIP 10.20.0.0-10.20.255.255 –ipTunnel NS_Cisco_Tunnel  

    Done
    > apply pbrs

    Done

To create an IPSEC profile by using the GUI

  1. Navigate to System > CloudBridge Connector > IPSec Profile.
  2. In the details pane, click Add.
  3. In the Add IPSec Profile dialog box, set the following parameters:
    • Name
    • Encryption Algorithm
    • Hash Algorithm
    • IKE Protocol Version
  4. Configure the IPSec authentication method to be used by the two CloudBridge Connector tunnel peers to mutually authenticate: Select the Pre-shared key authentication method and set the Pre-Shared Key Exists parameter.
  5. Click Create, and then click Close.

To create an IP tunnel and bind the IPSEC profile to it by using the GUI

  1. Navigate to System > CloudBridge Connector > IP Tunnels.
  2. On the IPv4 Tunnels tab, click Add.
  3. In the Add IP Tunnel dialog box, set the following parameters:
    • Name
    • Remote IP
    • Remote Mask
    • Local IP Type (In the Local IP Type drop down list, select Subnet IP).
    • Local IP (All the configured IPs of the selected IP type are in the Local IP drop down list. Select the desired IP from the list.)
    • Protocol
    • IPSec Profile
  4. Click Create, and then click Close.

To create a PBR rule and bind the IPSEC tunnel to it by using the GUI

  1. Navigate to System > Network > PBR.
  2. On the PBR tab, click Add.
  3. In the Create PBR dialog box, set the following parameters:
    • Name
    • Action
    • Next Hop Type (Select IP Tunnel)
    • IP Tunnel Name
    • Source IP Low
    • Source IP High
    • Destination IP Low
    • Destination IP High
  4. Click Create, and then click Close.

To apply a PBR by using the GUI

  1. Navigate to System > Network > PBRs.
  2. On the PBRs tab, select the PBR, in the Action list, select Apply.

The corresponding new CloudBridge Connector tunnel configuration on the Citrix ADC appliance appears in the GUI. The current status of the CloudBridge connector tunnel is shown in the Configured CloudBridge Connector pane. A green dot indicates that the tunnel is up. A red dot indicates that the tunnel is down.

Monitoring the CloudBridge Connector Tunnel

You can monitor the performance of CloudBridge Connector tunnels on a Citrix ADC appliance by using CloudBridge Connector tunnel statistical counters. For more information about displaying CloudBridge Connector tunnel statistics on a Citrix ADC appliance, see Monitoring CloudBridge Connector Tunnels.