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sys-cmd nslookup
sys-cmd nslookup resolves a name to an IP address or an IP address to a name from the route table selected in WEB-CLI and shows the result in a short form. It is used to answer the question "Is this name resolved, and to which address?" quickly; when details such as the TTL and the authority are needed, dig is preferred.
Command Summary
# type nslookup and press Tab: a free parameter
admin@TR7LBWAF01> sys-cmd nslookup
<nslookup-parameter-1>
admin@TR7LBWAF01> sys-cmd nslookup <options> <name-or-ip> <server>
admin@TR7LBWAF01>
Everything written after the word nslookup is passed to the tool as it is. There is no mandatory field; the options are written before the name, and the optional query server at the very end.
How It Works
| Subject | Behavior |
|---|---|
| Context | The query is sent from within the selected v-device and route table. |
| The query server | If a server is not written at the very end, the default resolver on the device is used. |
| Duration | It closes by itself when the response arrives or when the waiting time expires. The name or the address to be queried is always written together with the command. |
| Pipe | The output can be filtered with | or written to a file with to-file. |
| Recording | Every run is written to the user logs. |
Frequently Used Parameters
| Parameter | What it does | What is written after it |
|---|---|---|
<name-or-ip> | Specifies the name to be queried or the IP address to be resolved in reverse | A domain name or an IP address |
<server> | Selects the DNS server to which the query will be sent | The IP address or the name of the server; it is written after the name |
-type= | Determines which record will be requested | A · AAAA · MX · NS · TXT · SOA · CNAME |
-port= | Selects a port of the server other than the default | A port number |
-timeout= | Determines the response waiting time | Seconds |
The table summarizes frequently used parameters; the full list and behavior depend on the version of the tool on the device.
Examples
admin@TR7LBWAF01> sys-cmd nslookup app.example.com
admin@TR7LBWAF01>
admin@TR7LBWAF01> sys-cmd nslookup app.example.com <gtm-dns-address>
admin@TR7LBWAF01>
admin@TR7LBWAF01> sys-cmd nslookup -type=MX example.com
admin@TR7LBWAF01>
admin@TR7LBWAF01> sys-cmd nslookup 10.0.7.20
admin@TR7LBWAF01>
Things to Know
Non-authoritative answer. It shows that the response came not from the authoritative server but from the cache of a resolver. In order to see the most up-to-date record, the query is directed to the authoritative server.- For a detailed diagnosis (the TTL, the resolution chain, the authority information)
digis used.
