Setting up the base network for BIG-IP means configuring elements such as the BIG-IP host name, a default gateway pool, interface media settings, and VLANs and self IP addresses. Configuration tasks for the BIG-IP base network are performed using the BIG-IP Setup utility. For information on using the Setup utility, see Chapter 2, Using the Setup Utility.
Once you have configured the base network elements with the Setup utility, you might want to further enhance the configuration of these elements. This chapter provides the information you need to perform these additional configuration tasks. You can perform these tasks using either the Configuration utility or the bigpipe command.
Elements you might want to further configure after running Setup are:
If your BIG-IP is an IP Application Switch, you also have three other BIG-IP features you can configure:
Like interfaces, VLANs, and self IP addresses, these features can be configured using either the Configuration utility or the bigpipe command.
Note: Once you have configured the base network, you can configure the high-level network. Examples of elements you configure as part of the high-level network are: Pools, rules, proxies, and network address translation (SNATs and NATs). For information on how to configure your high-level network, see Chapter 4, Configuring the High-Level Network.
A BIG-IP can have as few as two network interfaces and as many as twenty-nine. Before performing configuration tasks such as displaying interface status and settings, setting the media type, and setting the duplex mode, it is helpful to understand interface naming conventions.
By convention, the Ethernet interfaces on a BIG-IP take the name <s>.<p> where s is the slot number of the NIC, and p is the port number on the NIC. As shown in Figure 3.1, for the 4U platform, slot numbering is left-to-right, and port numbering is top-to-bottom. Note that slot 1 is reserved for the onboard NIC whether or not it is present.
For the 2U platform, slot numbering is top-to-bottom and port numbering is left-to-right as shown in Figure 3.2.
For the Application Switch, slot numbering is left-to-right and port numbering is top-to-bottom as shown in Figure 3.3. Note that slot 2 is used for the gigabit ports, and slot 3 for a dedicated administrative port.
When a bigpipe command calls for a list of interfaces, the list may consist of one or more interfaces, with multiple interfaces separated by spaces. For example:
2.1 2.2 2.4 2.6
Use the following syntax to display the current status and the settings for all installed interface cards:
b interface show
Figure 3.4 is an example of the output you see when you issue this command on an active/standby unit in active mode.
interface speed pkts pkts pkts pkts bits bits errors trunk STP
Mb/s in out drop coll in out
5.1 UP 100 HD 0 213 0 0 0 74.2K 0
4.1 UP 100 HD 20 25 0 0 28.6K 33.9K 0
Use the following syntax to display the current status and the setting for a specific interface.
b interface <if_name> show
Properties that are configurable on the interfaces include media type and duplex mode, as shown in Table 3.1.
You may specify a media type or use auto for automatic detection.
You may specify a full or half duplex mode, or use auto for automatic selection.
You can set the media type to the specific media type for the interface card or to auto for auto detection. If the media type is set to auto and the card does not support auto detection, the default type for that interface is used, for example 1000BaseTX.
Use the following syntax to set the media type:
b interface <if_name> media <media_type> | auto
(Default media type is auto.)
Note: If the BIG-IP is inter-operating with an external switch, the media setting should match that of the switch. For more information, see Setting the interface media type, on page 2-6.
You can set duplex mode to full or half duplex. If the media type does not allow duplex mode to be set, this is indicated by an onscreen message. If media type is set to auto, or if setting duplex mode is not supported for the interface, the duplex setting is not saved to bigip_base.conf.
Use the following syntax to set the duplex mode:
b interface <if_name> duplex full | half | auto
(Default mode is auto.)
A VLAN is a grouping of separate networks that allows those networks to behave as if they were a single local area network, whether or not there is a direct ethernet connection between them.
BIG-IP offers several options that you can configure for a VLAN. These options are summarized in Table 3.2.
Create a default VLAN configuration
Use the Setup utility to create a default VLAN configuration.
Create, rename, or delete VLANs
Create, rename, or delete a VLAN.
Configure packet access to VLANs
Through an option called tagging, you can direct packets from multiple VLANs to a specific BIG-IP interface, or direct traffic from a single VLAN to multiple interfaces.
Manage the L2 forwarding table
You can edit the L2 forwarding table to enter static MAC address assignments.
Create VLAN groups
Create a VLAN group to allow layer 2 packet forwarding between VLANs.
Set VLAN security
You can set port lockdown by VLAN.
Set fail-safe timeouts
You can set a failsafe timeout on a VLAN. You can use a failsafe timeout to trigger fail-over in a redundant system.
Set self IP addresses
You can set one or more self IP addresses for VLANs.
Set MAC masquerade
You can use the MAC masquerade to set up a media access control (MAC) address that is shared by a redundant system.
By default, the Setup utility configures each interface on the BIG-IP as a member of a VLAN. The BIG-IP identifies the fastest interfaces, makes the lowest-numbered interface in that group a member of the VLAN external, and makes all remaining interfaces members of the VLAN internal. This creates the mapping shown in Figure 3.5.
As Figure 3.5 shows, VLAN flexibility is such that separate IP networks can belong to a single VLAN, while a single IP network can be split among multiple VLANs. (The latter case allows the BIG-IP to be inserted into an existing LAN without renaming the nodes.) The VLANs named external and internal are separate networks, and in the configuration shown they behave like separate networks. The networks belonging to VLAN internal are also separate networks, but have been made to behave like a single network. This is accomplished using a feature called VLAN bridging.
Your default VLAN configuration is created using the Setup utility. On a typical unit with two interfaces, you create an internal and external VLAN.
Typically, if you use the default configuration, one VLAN is assigned to each interface. However, if you need to change your network configuration, or if the default VLANs are not adequate for a network configuration, you can create new VLANs, rename existing VLANs, or delete a VLAN.
b vlan <vlan name> interfaces add <if name> <if name>
For example, if you want to create a VLAN named myvlan that contains the interfaces 1.1 and 1.2, type the following command:
b vlan myvlan interfaces add 1.1 1.2
b vlan <vlan name> rename <new vlan name>
For example, if you want to rename the VLAN myvlan to yourvlan, type the following command:
b vlan myvlan rename yourvlan
b vlan <vlan name> delete
For example, to delete the VLAN named yourvlan, type the following command:
b vlan yourvlan delete
The BIG-IP supports two methods for sending and receiving packets through an interface that is a member of one or more VLANs. These two methods are:
The method used by a VLAN is determined by the way that you add a member interface to a VLAN. When creating a VLAN or modifying VLAN properties (using the Configuration utility or the bigpipe command), you can add an interface to that VLAN as either an untagged or a tagged interface.
The following two sections describe these two methods of providing packet access to a VLAN.
Port-based access to VLANs occurs when an interface is added to a VLAN as an untagged interface. In this case, the interface can be added only to that VLAN and to no others. This limits the interface to accepting traffic only from that VLAN, instead of from multiple VLANs. To solve this problem, BIG-IP allows you to configure a feature known as tagging, described in the following section.
Tag-based access to VLANs occurs when an interface is added to a VLAN as a tagged interface. A tagged interface can be added to multiple VLANs, thereby allowing the interface to accept traffic from each VLAN of which the interface is a member.
When you add an interface to a VLAN as a tagged interface, BIG-IP associates the interface with the VLAN identification number, or tag, which becomes embedded in a header of a packet.
Note: Every VLAN has a VLAN identification number. This identification number is assigned to a VLAN either explicitly by a user, when creating the VLAN, or automatically by BIG-IP, if the user does not supply one.
Each time you add an interface to a VLAN, either when creating a VLAN or modifying its properties, you can designate that interface as a tagged interface. A single interface can therefore have multiple tags associated with it.
The result is that whenever a packet comes into that interface, the interface reads the tag that is embedded in a header of the packet. If the tag in the packet matches any of the tags associated with the interface, the interface accepts the packet. If the tag in the packet does not match any of the tags associated with the interface, the interface rejects the packet.
Figure 3.6 shows the difference between using three untagged interfaces (where each interface must belong to a separate VLAN) versus one tagged interface (which belongs to multiple VLANs).
The configuration on the left shows a BIG-IP unit with three internal interfaces, each a separate, untagged interface. This is a typical solution for supporting three separate customer sites. In this scenario, each interface can only accept traffic from its own VLAN.
Conversely, the configuration on the right shows a BIG-IP with one internal interface and an external switch. The switch places the internal interface on three separate VLANs. The interface is configured on each VLAN as a tagged interface. In this way, the single interface becomes a tagged member of all three VLANs, and accepts traffic from all three. The configuration on the right is the functional equivalent of the configuration on the left.
Not only can you add a single, tagged interface to multiple VLANs, as shown in the above example, you can also add multiple tagged interfaces to a single VLAN.
You configure tag-based access to VLANs using either the Configuration utility or the bigpipe vlan command. You can configure tag-based access either when you create a VLAN and add member interfaces to it, or by modifying the properties of an existing VLAN. In the latter case, you simply change the status of one or more member interfaces from untagged to tagged.
Creating a VLAN that supports tag-based access means creating the VLAN and then adding one or more tagged interfaces to it.
Configuring tag-based access on an existing VLAN means changing the existing status of one or more member interfaces from untagged to tagged.
b vlan external tag 1209
b vlan external interfaces add tagged 4.1 5.1 5.2
The effect of this command is to associate a tag with interfaces 4.1.and 5.1, which in turn allows packets with that tag access to the external VLAN.
The above procedure adds multiple tagged interfaces to a single VLAN. However, you can also add a single tagged interface to multiple VLANs (similar to the scenario presented in Figure 3.6). This results in a single interface having more than one tag associated with it. For example, the following commands add the tagged interface 4.1 to the two VLANs external and internal:
b vlan external interfaces add tagged 4.1
b vlan internal interfaces add tagged 4.1
Layer 2 forwarding is the means by which packets are exchanged directly between nodes on separate VLANs that are members of the same VLAN group, as described in Creating VLAN groups, on page 3-14. This is accomplished using a simple forwarding table for each VLAN with proxy forward enabled. The forwarding table has an entry for each node in the VLAN and associates the MAC address of that node with the BIG-IP interface using the following format:
<MAC address> -> <if>
00:a0:c9:9e:1e:2f -> 4.1
You can view the L2 forwarding table, delete entries, and add static entries. The entries that appear in the table automatically are learned and periodically updated and are called dynamic entries. Entries that you add to the table manually are called static entries. Static entries are not automatically updated. Entering static entries is useful if you have network devices that do not advertise their MAC addresses.
You can view and edit the L2 forwarding table using the bigpipe vlan <vlan_name> fdb command. The <vlan_name> may be either a VLAN or a VLAN group.
Type the following command:
b vlan <vlan name> fdb show
b vlan internal fdb show
This produces a display such as the following:
Forwarding table --
00:40:05:30:cc:94 -> 5.1)
Type the following command:
b vlan <vlan name> fdb show static
b vlan internal fdb show static
Type the following command:
b vlan <vlan name> fdb show dynamic
b vlan internal fdb show dynamic
Type the following command:
b vlan <vlan name> fdb add <MAC address> interface <ifname>
b vlan internal fdb add <MAC address> interface <ifname>
Type the following command:
b vlan <vlan name> fdb delete <MAC address> interface <ifname>
b vlan <vlan name> fdb delete 00:a0:c9:9e:1e:2f interface 4.1
vlan <vlan name> fdb show static
vlan <vlan name> fdb show dynamic
vlan <vlan name> fdb show
Entries in the L2 forwarding table have a specified life span, after which they are flushed out if the MAC address is no longer present on the network. This process is called the L2 forward aging time and you can set it using the global variable L2 Aging Time. The default value is 300 seconds.
Type the following command:
b global l2_aging_time <time_in_seconds>
b global l2_aging_time 200
A VLAN group is a grouping of two or more VLANs belonging to the same IP network for the purpose of allowing layer 2 packet forwarding, also known as L2 forwarding, between those VLANs. L2 forwarding is the equivalent of bridging where you want communication between VLANs. By creating a VLAN group, nodes on the separate VLANs can exchange packets directly.
In the example shown in figure 3.5, VLANs external and internal represent separate networks that were originally a single network. You can make them behave like a single network again much like the networks contained in VLAN internal. You accomplish this by grouping them as shown in Figure 3.7.
To configure a VLAN group to use layer 2 forwarding, you must:
The following sections describe these procedures.
You can create a VLAN group from the command line using the vlangroup command. For example:
b vlangroup network11 vlans add internal external
You can assign a self IP address to the VLAN group using the bigpipe command, as follows:
b self <ip address> vlan <vlangroup name>
Layer 2 forwarding is enabled for the VLAN group using the vlan proxy_forward attribute. This attribute is enabled by default when the VLAN group is enabled. To verify that proxy forwarding is enabled, type the following command:
b vlans show
You can lock down a VLAN to prevent direct connection to the BIG-IP through that VLAN. You can override this lockdown for specific services by enabling the corresponding global variable for that service. For example:
b global open_ssh_port enable
To enable port lockdown, type:
b vlan <vlan_name> port_lockdown enable
To disable port lockdown, type:
b vlan <vlan_name> port_lockdown disable
For redundant BIG-IP pairs, you can enable a failsafe mechanism that will fail over when loss of traffic is detected on a VLAN, and traffic is not restored during the fail-over timeout period for that VLAN. You can enable a fail-safe mechanism to attempt to generate traffic when half the timeout has elapsed. If the attempt is successful, the fail-over is stopped.
Using the vlan command, you may set the timeout period and also arm or disarm the fail-safe.
To set the timeout, type:
b vlan <vlan_name> timeout <timeout_in_seconds>
To arm the fail-safe, type:
b vlan <vlan_name> failsafe arm
To disarm the fail-safe, type:
b vlan <vlan_name> failsafe disarm
You can share the media access control (MAC) masquerade address between BIG-IP units in a redundant pair. This has the following advantages:
The MAC address for a VLAN is the MAC address of the first interface to be mapped to the VLAN, typically 4.1 for external and 5.1 for internal. You can view the interfaces mapped to a VLAN using the following command:
b vlan show
You can view the MAC addresses for the interfaces on the BIG-IP using the following command:
b interface show verbose
Use the following syntax to set the MAC masquerade address that will be shared by both BIG-IP units in the redundant system.
b vlan <vlan_name> mac_masq <MAC_addr>
Find the MAC address on both the active and standby units, and pick one that is similar but unique. A safe technique for selecting the shared MAC address follows.
Suppose you want to set up mac_masq on the external interfaces. Using the b interface show command on the active and standby units, you note that their MAC addresses are:
Active: 3.1 = 0:0:0:ac:4c:a2
Standby: 3.1 = 0:0:0:ad:4d:f3
In order to avoid packet collisions, you now must choose a unique MAC address. The safest way to do this is to select one of the addresses and logically OR the first byte with 0x40. This makes the MAC address a locally administered MAC address.
In this example, either 40:0:0:ac:4c:a2 or 40:0:0:ad:4d:f3 would be a suitable shared MAC address to use on both BIG-IP units in the redundant system.
The shared MAC address is used only when the BIG-IP is in active mode. When the unit is in standby mode, the original MAC address of the network card is used.
If you do not configure mac_masq on startup, or when transitioning from standby mode to active mode, the BIG-IP sends gratuitous ARP requests to notify the default router and other machines on the local Ethernet segment that its MAC address has changed. See RFC 826 for more details on ARP.
A self IP address is an IP address mapping to one or more VLANs and their associated interfaces on a BIG-IP. You assign a self IP address to each interface on the unit as part of Setup configuration, and you also assign a floating (shared) alias for units in a redundant pair. (A floating self IP address is the address to which the servers behind the BIG-IP route traffic). You can create additional self IP addresses for health checking, gateway failsafe, routing, or other purposes. You can create these additional self IP addresses using the self command.
Use the following syntax:
b self <addr> vlan <vlan_name> [ netmask <ip_mask> ][ broadcast <broadcast_addr>] [unit <id>]
You can add any number of additional self IP addresses to a VLAN to create aliases. For example:
b self 18.104.22.168 vlan external
b self 22.214.171.124 vlan external
b self 126.96.36.199 vlan external
b self 188.8.131.52 vlan external
Also, any one self IP address may have floating enabled to create a floating alias that is shared by both units of a BIG-IP redundant pair:
b self 184.108.40.206 floating enable
Assigning a self IP address to an interface automatically maps it to the VLAN of which it is a member. Assigning a self IP address to an interface not mapped to an untagged VLAN produces an error message.
The self IP addresses you enable on the external VLAN determine the translation address for SNAT auto-mapping. For more information about SNAT auto-mapping, refer to Configuring SNAT automapping, on page 4-126.
Link aggregation is the grouping of links (individual physical interfaces) to form a trunk. Link aggregation increases the bandwidth of the individual links in an additive manner. Thus, four fast Ethernet links, if aggregated, create a single 400 Mbps link. The other advantage of link aggregation is link fail-over. If one link in a trunk goes down, traffic is simply redistributed over the remaining links.
A trunk must have a controlling link, and acquires all the attributes of that controlling link from layer 2 and above. The trunk automatically acquires the VLAN membership of the controlling link but does not acquire its media type and speed. Outbound packets to the controlling link are load balanced across all of the known-good links in the trunk. Inbound packets from any link in the trunk are treated as if they came from the controlling link.
A maximum of eight links may be aggregated. For optimal performance, links should be aggregated in powers of two. Thus, you ideally will aggregate two, four, or eight links.
Use the following syntax to configure a trunk from the command line:
b trunk <controlling_if> define <if_list>
Interfaces are specified using the s.p convention, where s is slot number and p is port number. An <if_list> is one or more such interfaces, with multiple interfaces separated by spaces.
For more information on interface naming, refer to Interface naming conventions, on page 3-2.
The BIG-IP Application Switch provides Spanning Tree Protocol (STP) implementation for loop resolution in configurations where one or more external switches is connected in parallel with the BIG-IP. You can use this feature to configure two or more interfaces on the unit as an STP domain. For interfaces in the STP domain, the spanning tree algorithm identifies the most efficient path between the network segments, and establishes the switch associated with that path as the root. Links forming redundant paths are shut down, to be re-activated only if the root fails.
The STP domain should contain all ports that are connected in parallel to an external switch where there are nodes on the link capable of generating or receiving traffic. A second domain is called for if there is an additional switch or switches connected in parallel with additional BIG-IP interfaces.
Warning: Use of STP may slow performance significantly, particularly if more than one STP domain is created, and may have unforeseen effects on complex networks. It is important to test your STP configuration before placing it online.
You can create or delete STP domains using the Configuration utility or from the command line.
To create an STP domain from the command line, use the following syntax:
b stp <stp_name> interfaces add <if _list> | all
For example, if you want to create an STP domain named mystp that contains the interfaces 1.1 and 1.2, type the following command.
b stp mystp interfaces add 1.1 1.2
If you want to create an STP domain named mystp that contains all interfaces on the BIG-IP, type:
b stp <stp_name> interfaces add all
To delete an STP domain, use the following syntax:
b stp <stp_name> delete
You can set the time intervals in seconds for hello, max_age, and forward_delay for the STP domain from the command line using the following syntax:
b stp <stp_name> hello <interval>
b stp <stp_name> max_age <interval>
b stp <stp_name> forward_delay <interval>
To add interfaces to an STP domain from the command line, use the following syntax:
b stp <stp_name> interfaces add <if _list>
To delete interfaces from an STP domain, use the following syntax.
b stp <stp_name> interfaces delete <if _list>
To disable an STP domain from the command line, use the following syntax:
b stp <stp_name> disable
To re-enable interfaces on an STP domain, use the following syntax:
b stp <stp_name> enable
To disable specific interfaces in the STP domain from the command line, use the following syntax:
b stp <stp_name> interfaces disable <if_list>
To re-enable interfaces in an STP domain, use the following syntax:
b stp <stp_name> interfaces enable <if_list>
The stpd does not automatically restart when you synchronize configurations between units in a BIG-IP redundant pair. In order to restart the stpd, type the following command:
bigstart restart stpd
For the IP Application Switch, you can copy traffic from any port or set of ports to a single, separate port. This is called port mirroring. You should attach a sniffer device to the target port (called the mirror-to port) for debugging and/or monitoring.
Port mirroring consists of specifying a mirror-to port and adding to it one or more ports (that is, a port list) to be mirrored. You can set up port mirroring using the Configuration utility or from the command line.
Use this bigpipe syntax for setting up port mirroring:
b mirror <mirror_to_if> interfaces add <if_list>
b mirror 3.24 interfaces add 3.1 3.3 3.10
You can delete individual interfaces from a port mirror, or you can completely delete a port mirror.
Use this bigpipe syntax to delete interfaces from the port mirror:
b mirror <mirror_to_if> interfaces delete <if_list>
b mirror 3.24 interfaces delete 3.10
Use this bigpipe syntax to delete the port mirror:
b mirror <mirror_to_if> delete
b mirror 3.24 delete