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The SonicWALL includes several built-in tools to help you troubleshoot network problems. These tools include:
DNS Name Lookup
Find Network Path
Ping
Packet Trace
Tech Support Report
TraceRoute
The SonicWALL includes the DNS Name Lookup tool that returns the numerical IP address of a domain name or if you enter an IP address, it returns the domain name.
Select DNS Name Lookup from the Choose a diagnostic tool menu.
Enter the host name to lookup in the Look up the name field and click Go. Do not add the prefix "http://". The SonicWALL then queries the DNS server and displays the result at the bottom of the screen.
Tip!
You must define a DNS server IP address in the Network tab of the General
section to perform DNS Name Lookup.
The Find Network Path tool shows whether an IP host is located on the LAN or the WAN. This is helpful in determining if the SonicWALL is properly configured. For example, if the SonicWALL “thinks” that a computer on the Internet is located on the LAN, then the SonicWALL Network or Intranet settings can be misconfigured. Find Network Path shows if the target device is behind a router, and the Ethernet address of the target device. Find Network Path also shows the gateway the device is using and helps isolate configuration problems.
Select Find Network Path from the Choose a diagnostic tool menu.
Enter the IP address of the device and click Go. The test takes a few seconds to complete. Once completed, a message showing the results is displayed in the browser window.
If the network path is incorrect, select the SonicWALL Intranet and Static Routes settings.
Tip!
Find Network Path requires an IP address. The SonicWALL DNS Name
Lookup tool can be used to find the IP address of a host.
The Ping test bounces a packet off a machine on the Internet and returns it to the sender. This test shows if the SonicWALL is able to contact the remote host. If users on the LAN are having problems accessing services on the Internet, try pinging the DNS server, or another machine at the ISP location. If this test is successful, try pinging devices outside the ISP. This shows if the problem lies with the ISP connection.
Select Ping from the Choose a diagnostic tool menu.
Enter the IP address of the target device to ping and click Go. The test takes a few seconds to complete. Once completed, a message showing the results is displayed in the browser window.
Tip!
Ping requires an IP address. The SonicWALL DNS Name Lookup tool can be
used to find the IP address of a host.
The Packet Trace tool tracks the status of a communications stream as it moves from source to destination. This is a useful tool to determine if a communications stream is being stopped at the SonicWALL, or is lost on the Internet.
To interpret this tool, it is necessary to understand the three-way handshake that occurs for every TCP connection. The following displays a typical three-way handshake initiated by a host on the SonicWALL LAN to a remote host on the WAN.
TCP received on LAN [SYN]
From 192.168.168.158 / 1282 (00:a0:4b:05:96:4a)
To 204.71.200.74 / 80 (02:00:cf:58:d3:6a)
The SonicWALL receives SYN from LAN client.
TCP sent on WAN [SYN]
From 207.88.211.116 / 1937 (00:40:10:0c:01:4e)
To 204.71.200.74 / 80 (02:00:cf:58:d3:6a)
The SonicWALL forwards SYN from LAN client to remote host.
TCP received on WAN [SYN,ACK]
From 204.71.200.74 / 80 (02:00:cf:58:d3:6a)
To 207.88.211.116 / 1937 (00:40:10:0c:01:4e)
The SonicWALL receives SYN,ACK from remote host.
TCP sent on LAN [SYN,ACK]
From 204.71.200.74 / 80 (02:00:cf:58:d3:6a)
To 192.168.168.158 / 1282 (00:a0:4b:05:96:4a)
The SonicWALL forwards SYN,ACK to LAN client.
TCP received on LAN [ACK]
From 192.168.168.158 / 1282 (00:a0:4b:05:96:4a)
To 204.71.200.74 / 80 (02:00:cf:58:d3:6a)
Client sends a final ACK, and waits for start of data transfer.
TCP sent on WAN [ACK]
From 207.88.211.116 / 1937 (00:40:10:0c:01:4e
To 204.71.200.74 / 80 (02:00:cf:58:d3:6a)
The SonicWALL forwards the client ACK to the remote host and waits for the data transfer to begin.
When using packet traces to isolate network connectivity problems, look for the location where the three-way handshake is breaking down. This helps to determine if the problem resides with the SonicWALL configuration, or if there is a problem on the Internet.
Select Packet Trace from the Choose a diagnostic tool menu.
Tip!
Packet Trace requires an IP address. The SonicWALL DNS Name Lookup tool
can be used to find the IP address of a host.
Enter the IP address of the remote host in the Trace on IP address field, and click Start. You must enter an IP address in the Trace on IP address field; do not enter a host name, such as “www.yahoo.com”.
Contact the remote host using an IP application such as Web, FTP, or Telnet.
Click Refresh and the packet trace information is displayed.
Click Stop to terminate the packet trace, and Reset to clear the results.
The Tech Support Report generates a detailed report of the SonicWALL configuration and status, and saves it to the local hard disk. This file can then be e-mailed to SonicWALL Technical Support to help assist with a problem.
Alert!
You must register your SonicWALL on mySonicWALL.com to receive technical support.
Before e-mailing the Tech Support Report to the SonicWALL Technical Support team, complete a Tech Support Request Form at <http://techsupport.sonicwall.com/swtech.html>. After the form is submitted, a unique case number is returned. Include this case number in all correspondence, as it allows SonicWALL Technical Support to provide you with better service.
Four Report Options are available in the Tech Support Report section:
VPN Keys - saves shared secrets, encryption, and authentication keys to the report.
ARP Cache - saves a table relating IP addresses to the corresponding MAC or physical addresses.
DHCP Bindings - saves entries from the SonicWALL DHCP server.
IKE Info - saves current information about active IKE configurations.
Select Tech Support Report from the Choose a diagnostic tool menu.
Select the Report Options to be included with your e-mail.
Click Save Report to save the file to your system. When you click Save Report, a warning message is displayed.
Click OK to save the file. Attach the report to your Tech Support Request e-mail.
Trace Route is a diagnostic utility to assist in diagnosing and troubleshooting router connections on the Internet. By using Internet Connect Message Protocol (ICMP) echo packets similar to Ping packets, Trace Route can test interconnectivity with routers and other hosts that are farther and farther along the network path until the connection fails or until the remote host responds.
Select TraceRoute from the Choose a diagnostic tool menu.
Enter the IP address or domain name of the destination host in the TraceRoute this host or IP address field.
Click Go.
A second window is displayed with each hop to the destination host. By following the route, you can diagnose where the connection fails between the SonicWALL and the destination.