IPv6 deployment starts at the network edge
Six ADCs deliver IPv6 capabilities to apps hosted on IPv4 Web servers
IT execs know they will have to deploy IPv6 at some point, but where to begin? One approach that establishes some IPv6 capability without spending a lot of time or money is to start at the perimeter.
IPv6-enabling routers, firewalls and DNS servers should be straightforward. If an organization were to deploy an IPv6-capable Server Load Balancer (SLB) or, using the most current term, Application Delivery Controller (ADC), they could configure an IPv6 Virtual IP (VIP) and an IPv4-only server farm.
This would allow Web apps hosted on IPv4-only servers to appear to the Internet user as IPv6-applications. The way it works is that clients would connect to the IPv6 VIP, and the ADC would perform a reverse-proxy function and terminate the IPv6 HTTP Internet connection, then create a new IPv4 HTTP back-end connection to the IPv4-only application servers. The server would not necessarily know the IP version being used by the client and it would happily return the data to the ADC appliance using IPv4. The ADC appliance takes that IPv4 response from the server, copies the HTTP application data and transmits it back to the IPv6-connected client.
Quiz: are you ready for IPv6?
We tested the IPv6 capabilities of the major ADC vendors' products: A10 Networks, Brocade, Cisco, Citrix, F5 and Riverbed/Zeus. We tested all of the IPv6 features that these vendors listed on their data sheets and determined that all of these systems are suitable for aiding in an Internet edge IPv6 deployment scenario.
One piece of good news: The ADC your company already owns may have IPv6 capabilities. It could be as simple as a software upgrade and you would have an IPv6-capable reverse proxy server that could help accelerate your IPv6 Internet edge deployment.
Long list of features
ADCs can provide a wide variety of IPv6 capabilities. Most of the products tested had these features.
• IPv4/IPv6 Server Load Balancing (reverse proxy), IPv6 VIP with IPv4 or dual-protocol real-servers/server-farms
• SSL offload and acceleration for IPv6-VIPs and servers
• Ability to perform content filtering, regular expression matching, URL rewriting, for IPv6 connections
• IPv6-capable Web Application Firewall (WAF)
• IPv6-enabled security features (distributed denial-of-service (DoS) protection, SYN-cookies, IPS, content filtering)
• Stateful access control lists f(ACL) or IPv6 packets, ICMPv6 filtering, extension header filtering and denial of RH0 packets
• High-availability for IPv6 connections (IPv6 connection state synchronization between high availability pairs)
• Logging of IPv6 connections (internal logging and with Syslog)
• Ability to check the IPv6 neighbor cache entries
• IPv6 static routing
There are also some nice-to-have optional features.
• IPv6-enabled Geographical Server Load Balancing (GSLB)
• Authoritative dual-protocol DNS server
• Stateful NAT64 capabilities
• DNS64 integration with NAT64
• IPv6 routing protocol support (static routing, RIPng, OSPFv3, IS-IS [ST & MT], MP-BGP, RHI)
• Management with IPv4 and IPv6
There are also IPv6 features that apply to ISPs or large-scale data center companies.
• Large Scale NAT (LSN), Carrier Grade NAT (CGN), NAT444
• 6rd (IPv6 Rapid Deployment) border relay
• Dual-Stack Lite (DS-Lite) AFTR
Many of these features have crept into ADC products over several years. Some are included as part of the base licensing, but be aware that some vendors may charge a premium for these IPv6 features.
We set up a testing environment that mimicked a typical Internet edge environment. We had an IPv4-only perimeter and we enabled it for IPv6. We performed testing from the perspective of an IPv6-enabled Internet user trying to establish connectivity to an IPv4-only web server. We also tested NAT64 functionality where an IPv6-only client may be trying to reach IPv4 Internet content.
We tested each of these six ADCs and found that they were all capable of basic IPv4 and IPv6 server load balancing with SSL offload. We found that the support for IPv6 management, IPv6 routing, and service-provider IPv6 features varied quite widely among the vendor's solutions. We found that all of these products would be suitable in an enterprise Internet perimeter environment and would aid in the transition to IPv6.
Scariest IPv6 attack scenarios
Here are the individual reviews:
A10 Networks AX2500: Highly scalable, feature rich, lacks web app firewall
A10 first started supporting IPv6 in their AX series in 2007. Since then, A10 has fully embraced IPv6. Today, A10 offers two version of their software: one (2.6.1) for IPv6 SLB and one (2.6.6) for NAT64/DNS64/DS-Lite/6rd and Large Scale NAT (LSN), also known as CGN or NAT444 (IPv4 preservation).
A10 also has a SoftAX virtual appliance for lab or production environments. We tested an AX2500 which lists for $24,995, however, A10 has appliances that range from $15,995 to $215,000 and their SoftAX virtual appliance can cost between $995 and $24,995. The great thing is that all the AX features are included without additional license fees.
The A10 Networks AX series of ADCs have many IPv6 features including IPv4/IPv6 SLB with SSL offload and GSLB over IPv6. The AX can perform Syslog for IPv6 connections using aFleX Tcl scripts. The AX also allows Ping and management access using SSH, HTTP/HTTPS, SCP and SFTP over IPv6 transport.
Unfortunately, there are no IPv6 WAF capabilities in this version, but A10 appliances can integrate with other market-leading WAFs such as Imperva. We found that the A10 does provide other security features like protocol checking for HTTP, HTTPS, and DNS, distributed DoS protections, rate limiting, and ACLs.
Our testing determined that A10 supports static IPv6 routes and dynamic routing protocols for IPv6. The A10 can be configured for RIPng, OSPFv3, IS-IS and BGP.
A10's SoftAX virtual appliance can help support an organization's cloud computing and virtualization goals. The A10 AX appliances also support multi-tenancy and virtual chassis configurations.
AX appliances have extensive scalability due to their 64-bit architecture and their Advanced Core Operating System (ACOS). However, scalability may not be a concern for enterprises who may initially have low IPv6 traffic volumes.
The A10 Networks systems also provide service-provider features such as NAT64 and DNS64. The 2.6.6 software can be configured for NAT64 with DNS64, but there is also a documented Infoblox integration of DNS64 for A10's NAT64 configurations. The Large Scale NAT (LSN), DS-Lite, 6rd, NAT64/DNS64 scalability of these appliances makes them attractive to service providers. In fact, the A10s compete well with more costly heavy-iron solutions from the large router vendors.
Brocade ServerIron ADX: Newly updated software deliver rich feature set, but no Web app firewall
Brocade acquired Foundry Networks in 2008 and Brocade has continued innovating its routers, switches, and server load balancers. Brocade first starting adding IPv6 features to the ServerIron ADX platform in Version 11.0 and has continued to add IPv6 features to this ADC. We tested a Brocade ServerIron ADX 1216-4-SSL-PREM running Version 12.3.1 and the latest software Version 12.4.00T405 which has a list price of $45,995.
This system has the Premium License which includes Layer 3 Routing, IPv6, GSLB and an additional license for SSL offload. Brocade very recently came out with this new software that adds to the number of available IPv6 features. One item of note is that Brocade has a "pay-as-you-grow" licensing model and licenses the ADXs based on the software features, number of processors and bandwidth you require. Therefore, to get IPv6 capability on the ADX you must purchase the Premium License.
The ADX supports IPv4 and IPv6 Server Load Balancing as a reverse proxy server. VIPs can use either IPv4 or IPv6 addresses and have either IPv4 or IPv6 real servers. Brocade has completely rewritten their IP stack to accommodate and streamline IPv6. However, our testing revealed that their system only supports SSL offload for IPv4 VIPs using IPv4 real servers or IPv6 VIPs using IPv6 real servers. In software release 12.4, the ADX will be able to perform SSL offload for IPv6 VIPs using IPv4 real servers and mixed protocol server farms.
We set up the ADX and configured web management over IPv6 and we also entered IPv6 addresses into the configuration through the web GUI. We used SSH over IPv6 transport and SNMP worked over IPv6. Syslog did not work for IPv6 Syslog servers but IPv6-related log messages can be sent to an IPv4 Syslog server.
The ADX also supports a wide variety of IPv6 routing protocols including OSPFv3, IS-IS (Single-Topology or Multi-Topology) and MP-BGP.
The ADX offers IPv6 security features and allows you to configure complex IPv6 access-lists. The ADX now supports SYN-Proxy (SYN-cookies) for IPv6 traffic and setting the MSS works for IPv4 or IPv6 packets. We found that other features such as distributed DoS protection, IPS, and content filtering are also IPv6-capable. However, the Brocade ServerIron does not have an IPv6-capable WAF.
The ServerIron ADX can act as an authoritative dual-protocol DNS server, function as a DNS proxy server and perform IPv4 and IPv6 GSLB.
The Brocade ADX supports NAT64 in the same software and hardware, but it is configured in a different operating mode from traditional SLB functions. Our testing determined that you cannot have a single ADX appliance function as a NAT64 system and a server load balancer at the same time.
The ADX has capabilities for IPv6-only or IPv4-only clients. The Brocade ServerIrons can perform Large Scale NAT (LSN)/Carrier Grade NAT (CGN)/NAT444, but do not currently support 6rd or DS-Lite.
Cisco ACE A5: Late to the IPv6 party, features are somewhat limited
The Cisco Application Control Engine (ACE) has been available for many years in many forms but only a few months ago did the Cisco ACE begin to support IPv6. ACE software release A5 (1.1) runs on the ACE30 module for a Cisco 6500 switch and the ACE4710 appliance. Unfortunately, customers who have invested in ACE10 or ACE20 modules will not be able to use this version and will face hardware upgrades to support IPv6. There are ACE10/20 to ACE30 upgrades available for $30,000. The device that we tested was the ACE-4710-01-K9 running software Version A5 (1.1) which has a list price of $29,995.
Cisco ACE modules and appliances have licensing that allows the upgrade of the performance of the units, the number of SSL connections and number of virtual contexts. There is no additional charge for IPv6 support on the ACE. If you are familiar with configuration of Cisco devices using contexts then you will feel right at home with this system.
The Cisco ACE performed server load balancing for IPv6 VIPs with IPv6 real servers and IPv6 VIPs with IPv4 real servers. We easily configured IPv6 health probes and the Layer-4/Layer7 policies and SSL offload work for IPv6 connections. HTTP/HTTPS and DNS inspection (application awareness) work for native IPv6-IPv6 traffic. The ACE allowed us to configure IPv6 ACLs and perform packet capture of IPv6 packets. The ACE has IPv6 security features and it can filter extension headers, perform fragmentation inspection, IPv6 ICMP-guard, IPv6 normalization, and IPv6 Unicast-RPF checking. The ACE can act as a DHCPv6 relay and can either send Routing Advertisements on its Ethernet interfaces or suppress them. In the ACE, fault tolerance is not supported over IPv6 but it can track IPv6 connectivity and use IPv6 alias addresses on its interfaces.
The ACE does have some limitations. It does not support IPv6 dynamic routing protocols, but it does have IPv6 static routing and IPv6 Route Health Injection (RHI). The ACE does not have stateful NAT64 with or without DNS64. We could not configure IPv6 transport for management protocols (SSH, Telnet, SNMP, HTTP/HTTPS) but IPv6 MIB values are available for SNMP query over IPv4 transport.
We were able to perform IPv6 configuration through the web GUI, but it is only accessible over IPv4. We could ping the ACE using ICMPv6 and could send syslog messages with IPv6 addresses in them. The ACE GSS 4492 does have IPv6 support for GSLB. However, in August, Cisco announced end of sales for their ACE Web Application Firewall (WAF) so it will never be IPv6-capable.
Citrix NetScaler: Fully featured, easy to configure
NetScaler has supported IPv6 for more than seven years. IPv6 capabilities are available in the platinum, enterprise, and standard edition feature sets and now IPv6 comes enabled by default for no additional cost. We tested using a Citrix NetScaler MPX7500 running software Version 9.3-52.3 that costs $22,000. In addition to Citrix's hardware appliances, the company offers a virtual appliance called the NetScaler VPX.
It was easy to configure IPv6 addresses on interfaces and VLANs through either a command line interface (CLI) or the GUI. The Netscaler supports configuring IPv6 VIPs with IPv6 or IPv4 services. SSL offload worked for IPv6 and health probes operate over IPv6. Content switching worked for IPv6 connections and regular expressions could be created using IPv6 addresses. URL rewriting also worked for IPv6 VIPs. We could configure IPv6 for RADIUS servers, TACACS+ servers, LDAP servers, Syslog servers, and DNS servers.