This article provides information on how to add static DNS mappings in SRX devices.

 

The requirement is to add static DNS mappings; for example, if you want www.abc.com, no DNS requests should be sent to a DNS server and it should automatically be resolved to an IP address (for example, 1.1.1.1).

 

There are a couple ways to achieve this:

Add host to /etc/hosts file.

To add the static DNS mappings, modify the /etc/hosts file on the SRX device as follows:

1. Go to the shell:

root@SRX> start shell

2. Edit the /etc/hosts file via the VI editor:

root@SRX% vi /etc/hosts

3. Press i to enter the insert mode and add the following entry:

1.1.1.1 www.abc.com

4. Type : wq to save the file.

Then, when you try to ping www.abc.com, the SRX device will automatically ping 1.1.1.1:

root@SWITCH# run ping www.abc.com
PING www.abc.com (1.1.1.1): 56 data bytes

 

Use static-host-mapping

Another method is to add an alias to an IP address using the static-host-mapping option:

root# set system static-host-mapping DPT inet 1.1.1.1
root# set system static-host-mapping DPT alias abc.com
root# commit

You can also add host-name to an IP address:

root# set system static-host-mapping www.abc.com inet 1.1.1.1
root# commit

root# run ping abc.com
PING abc.com (1.1.1.1): 56 data bytes
64 bytes from 1.1.1.1: icmp_seq=0 ttl=57 time=31.675 ms
64 bytes from 1.1.1.1: icmp_seq=1 ttl=57 time=31.133 ms
64 bytes from 1.1.1.1: icmp_seq=2 ttl=57 time=31.152 ms
^C
--- abc.com ping statistics ---
3 packets transmitted, 3 packets received, 0% packet loss
round-trip min/avg/max/stddev = 31.133/31.320/31.675/0.251 ms

For more information, refer to static-host-mapping.

 

2020/07/27: Article reviewed for accuracy; no changes required; article valid and relevant