Cisco Cisco Email Security Appliance C190 Technical References

Use the 

nslookup

 command to check the DNS functionality.

The 

nslookup

 command can confirm that the appliance is able to reach and resolve hostnames and IP 

addresses from a working DNS (domain name service) server.

Commit: This command does not require a ‘commit’.

Cluster Management: This command can be used in all three machine modes (cluster, group, machine).

Batch Command: This command does not support a batch format

mail.example.com> nslookup

Please enter the host or IP address to resolve.

[]> vm30esa0086.ibqa

Choose the query type:

1. A       the host's IP address

2. AAAA    the host's IPv6 address

3. CNAME   the canonical name for an alias

4. MX      the mail exchanger

5. NS      the name server for the named zone

6. PTR     the hostname if the query is an Internet address,

otherwise the pointer to other information

7. SOA     the domain's "start-of-authority" information

8. TXT     the text information

[1]> 2

AAAA=2001:420:54ff:ff06::95 TTL=30m

A

the host's Internet address

CNAME

the canonical name for an alias

MX

the mail exchanger

NS

the name server for the named zone

PTR

the hostname if the query is an Internet address, otherwise the pointer 
to other information

SOA

the domain's “start-of-authority” information

TXT

the text information