Review: SonicWALL firewalls for less than $1,000

SonicWALL TZ200 and TZ210 deliver enhanced features

1 2 3 Page 2
Page 2 of 3

The TZ200 and TZ210 can also act as wireless switches, controlling SonicWALL's external wireless device, the SonicPoint-N, a $400 managed access point. (The TZ200 can manage 2; the TZ210 up to 16). These are SonicWALL's best-kept secrets, a managed wireless LAN similar to Cisco or Aruba's wireless switch and access point technology, but at a fraction of the price.

The SonicPoint-N has all the features you'd expect from an enterprise managed wireless network. A few important features, such as multiple SSIDs, have been blocked out of the TZ series. SonicPoints go further and do more than the built-in wireless on the TZ200 and TZ210. For example, features such as wireless RF monitoring for common attacks and problems can be configured on SonicPoints, but not in the built-in wireless. More to the point, you have to configure SonicPoints and the built-in wireless separately, so if you do buy into the SonicWALL wireless story, you have to treat the wireless built into the TZ200 and TZ210 differently from your SonicPoints — really, not the best of ideas. The built-in wireless should look and act just like a SonicPoint for maximum integration, but it doesn't. And, if you do use SonicPoints, you can't connect them to the Gigabit Ethernet ports on your TZ210, because those ports are already dedicated to other functions. This restriction means you'll never get the full benefits of the 802.11n wireless because you'll be stuck on a 100Mbps interface. This doesn't seem very well thought out or balanced.

Although the 802.11n is a welcome addition, SonicWALL should have gone further with the experience they have from their SonicPoint line in giving a more powerful wireless feature set to the TZ series.

Advanced threat mitigation features

With the new TZ200 and TZ210, SonicWALL is continuing its power push into the UTM feature set. In addition to the existing content filtering, IPS and antimalware tools, this version of SonicOS brings SonicWALL's Application Firewall (TZ210 only) and antispam service to the SMB marketplace.

The IPS, content filtering and antimalware features are not significantly changed from earlier versions. SonicWALL offers both its own Content Filtering Service as well as an option for the Websense engine. Both antimalware and IPS use SonicWALL's own service only. We found configuration for antimalware (which SonicWALL breaks into antivirus, which can run across all traffic, and antimalware, which is limited to HTTP, FTP and e-mail protocols) to be straightforward.

We tested antimalware by taking the 15 most recent, unique, viruses that were in our corporate antivirus quarantine and trying to re-send them through the TZ210 firewall. Out of the 15 viruses, the TZ210 failed to identify two suspected viruses. We submitted these to the Virustotal multiple-engine scanning service, which gave a 78% "is a virus" score for one of them, and an 87% score for the other. The TZ210 turned in the same results whether we used the FTP, HTTP, or SMTP to transfer the files. In an earlier test, we had also found that SonicWALL effectively found viruses on non-standard ports, a unique feature in this marketplace. We stressed this by trying both HTTP and SMTP on non-standard ports, and found that while the TZ210 was able to identify malware in HTTP traffic on non-standard ports, it did not work properly on SMTP traffic on non-standard ports. This isn't much of a defect, but network managers should be aware of this when considering their outbound and inbound SMTP policies.

We did not look in depth at the TZ210 content filtering service, other than to verify that it caught some obvious URLs. As with antimalware, configuration of content filtering is extremely straightforward.

Our experience with SonicWALL's Application Firewall was less positive. Although the Application Firewall definitely performed as advertised, we found it difficult to use and hard to trust. The Application Firewall is a new feature to this product line (it has been available in the higher-end NSA series since they were released) that allows the network manager to build policies based on very deep inspection of mail (SMTP, POP and IMAP), FTP and HTTP protocols, as well as SonicWALL's IPS signatures. For example, traffic can be caught by the Application Firewall based on the "Subject" line of an e-mail.

Once the Application Firewall picks out traffic, you can then apply policies, including simply blocking the traffic, or using more sophisticated actions, such as blocking e-mail attachments, adding text to messages, blocking or redirecting HTTP pages, and applying bandwidth management. Policies have a variety of other qualifiers as well, such as IP addresses, zones, username and group membership, and time of day.

As we quickly discovered, not every action is supported with every content match and with every protocol. SonicWALL provides a very good tutorial on the Application Firewall with numerous examples of ways to use this to enforce policy compliance, which is a must-read if you want to really understand what is going on. Although you only can define a very limited number of policies — five in the case of the TZ210 we tested — each policy is very powerful.

For example, we wanted to use the Application Firewall to enforce bandwidth limits for streaming video. To do that, we had to use IPS signatures. The category "Multimedia" is too broad (it covers, for example, audio file downloads as well as video), so we had to browse through the 208 signatures to find which ones would cover what we wanted. Unfortunately, there is no easy way to get documentation on each signature other than its short name (typically 40 characters or less) as you're configuring the Application Firewall.

Fortunately, we could pile as many signatures as we wanted in a single policy, even if doing so was incredibly tedious. We also felt that we were wandering a bit in the weeds with some of the signatures.

In the end, we got the policy we wanted with only a moderate amount of research, and the simple testing we did showed that the TZ210 identified unencrypted video traffic from popular video sites and was able to enforce bandwidth limits. The Application Firewall was a success, and the amount of work it took to define a policy seems high compared to other operations on the TZ210.

However, the  Application Firewall goes where other firewalls can't, and gives you the flexibility to define security policy you've never been able to build before in this type of device. Is it an out-of-the-ballpark home run? No, but it's a great tool and one that could save you from having to buy another piece of hardware or another software package.

The last new security feature we tested on the TZ210 was SonicWALL's antispam service. This is an in-the-cloud offering that uses the firewall to redirect traffic to the antispam service, which does content filtering, and then sends the non-spam e-mail back to your local mail server. Unlike other antispam services, the TZ210 antispam doesn't require you to change your DNS. Using a combination of firewall and NAT policies and some internal smarts, the TZ210 simply redirects connections to their service, which lets you turn on and off the antispam quickly while testing. The SonicWALL antispam service isn't a complete in-the-cloud offering because you must provide your own quarantine server (an application SonicWALL includes which sits on an existing Microsoft Exchange server) if you want to quarantine suspected spam, viruses and phishing messages.

We did not have an opportunity to test the effectiveness of the antispam service on a production mail stream. However, we did set up the antispam service and found it easy to install with very little aggravation — as long as you have a very simple setup with a single mail server, a small number (five or less) domains you want to filter, and a willingness to let your mail fly out into the cloud unprotected.

The TZ210 antispam service strips out any server-to-server encryption you may have configured, and all communication between the TZ210 and the in-the-cloud service is unencrypted, which could be a concern in some environments where server-to-server encryption is used to ensure privacy.

Performance of the antispam service will likely not be much of an issue, even though your mail travels over your Internet connection three times (in to the firewall, back out to SonicWALL, and then back to the firewall for delivery). SonicWALL's documentation says it uses its own reputation services to block incoming connections. Our testing showed that this isn't exactly true, although reputation services (and their ability to limit wasted bandwidth) do come into play once a spammer has already connected to the firewall.

Our limited testing didn't give us the ability to really offer a verdict on whether the antispam service is a winner. However, SonicWALL includes a free trial, and it's very easy to test this for yourself.

SSL VPN

Included with the new TZ100, TZ200 and TZ210 firewalls are licenses for a newly included SSL VPN function. The TZ100 and TZ200 come with one user license, expandable to five and 10 users (respectively), while the TZ210 comes with a two-user license, expandable up to 10 users.

This isn't in the same league as SonicWALL's enterprise-class SSL VPN appliance the company added to its portfolio when it purchased Aventail in 2007; it's a simple network extension that is a competitor to IPsec VPN (also included with each device if you insist) for remote access.

The SSL VPN is simple to add and configure. Users appear in the SSL VPN as if they were in a new zone, so you simply write normal zone-based firewall rules to define your access controls. The SSL VPN includes a simple portal that can be used to launch or download the Java-based SSL VPN client (available for Windows, Macintosh, and Linux operating systems).

A small set of SSL VPN specific settings, such as whether to use split tunneling, whether clients can communicate with each other or whether the username and password can be saved, are about all you need to worry about to set up the SSL VPN.

Users for the SSL VPN can be stored locally on the firewall appliance, or the firewall can talk to a RADIUS or LDAP server for authentication. We linked our TZ210 to a running Active Directory domain and saw great evidence of SonicWALL's experience dealing with LDAP technical support — the configuration was well documented, easy to do, but not so ridiculously simple that we couldn't make some important customizations to make the TZ210 talk properly to our LDAP server. This kind of easy connection is one of the important differentiators between a product that fits quickly into enterprise infrastructure and one that doesn't go much beyond the demo stage. Because the TZ210 linked up so easily, we weren't even tempted to use the local user database — a better security configuration in the long run.

The SSL VPN built into the TZ200 and TZ210 is a great replacement — if you buy the extra user licenses — for the harder-to-use and less predictable IPsec VPN in earlier versions.

Performance

We tested the TZ200 and TZ210 using the same performance-testing methodology we used in 2007 when we looked at UTM firewalls and in our 2008 test of the SonicWALL NSA E7500 appliance. We found that the TZ200 and TZ210 beat their data sheet numbers in some cases, and don't live up to them in others.

For raw speed, without UTM features enabled, we found the TZ210 turned in a goodput of 118Mbps using a typical Internet traffic mix, with a total throughput of 126Mbps; the TZ200 91Mbps goodput and 97Mbps throughput. Goodput measures only application layer data, while throughput also includes header information. Most vendors quote throughput numbers in their performance stats, but goodput is a better measure of what you'll actually see at the end system. Both devices beat their data sheet IMIX numbers easily.

When we turned on UTM features, performance — as expected — was dramatically affected. SonicWALL does not really distinguish between server-side and client-side IPS, so we tested IPS with and without the Application Firewall to see a range of performance. The TZ210 slowed down about 35% while the TZ200 only dropped about 12%. In fact, the TZ200 outperformed the TZ210 in pure IPS throughput, a result that SonicWALL wasn't able to easily explain.

With antimalware enabled, we saw a much more significant drop in both systems, although both dropped to about the same speed: approximately 13Mbps. That's nearly 90% performance hit for the TZ210, and 86% hit on the TZ200. Neither system comes very close to its datasheet specifications for antimalware performance. We discussed these UTM results at length with SonicWALL's product management team. Although they were at first very surprised by the results, they were able to confirm them in their own test lab. We also varied our test methodology and tried four different approaches, all of which returned roughly similar performance numbers.

SonicWALL explained that their original performance specifications were based on testing they did using SonicOS 5.1, while we were testing with SonicOS 5.5. During the upgrade, some new signatures were added to the UTM feature and these were causing the performance slowdown we saw. Unfortunately, there was no easy way to identify which signatures were causing the problem on short notice, although they promised to work to improve UTM performance as quickly as possible.

1 2 3 Page 2
Page 2 of 3
SD-WAN buyers guide: Key questions to ask vendors (and yourself)