Red Hat® Linux® 7 Unleashed

Troubleshooting DNS

Many DNS troubleshooting techniques were discussed previously in this chapter, such as using the telnet program to detect reverse-DNS problems. Other troubleshooting options include script programs and named logging options.

Using Scripting to Stress-Test Your DNS Setup

You can make two handy scripts to stress-test your DNS setup. They can be named anything, but this example calls them check1 and check. The check1 script simply records the results of an nslookup in file junk.jnk, while check calls check1 for each domain and IP under consideration. Here's the code for check1:

echo "nslookup $1 $2" >> junk.jnk
nslookup $1 $2 >> junk.jnk
echo " " >> junk.jnk
echo " " >> junk.jnk

check1 simply writes the nslookup of its arguments ...