domain-name and FQDN resolution

[bastien1]

Hello everyone,

I don't understand how exactly a FQDN name is resolved.

Here is an example of a DHCP server configured on a Cisco layer 3 switch :

ip dhcp pool MY_NETWORK

network 172.16.1.0 255.255.255.0

dns-server 8.8.8.8

default-router 172.16.1.1

lease 0 23 59 

domain-name mynetwork.local

In this network, for instance, I have a layer 2 switch and its hostname is "SW1".

Imagine I want to ping it using its hostname (so using the command "ping SW1").

This command will then ping "SW1.mynetwork.local", but how can it be resolved if this hostname is not mapped in my DNS server ?

Do I need to create a DNS record on the DNS server ?

If it is not necessary, how does the resolution occur exactly ?

Regards,

Bastien.

[Jon Marshall · Accepted solution]

Yes you need an entry on your DNS server if you want to ping to it by name.

The alternative is to configure host names locally on the device you want to ping from ie. on a PC or you can add them to Cisco devices but it is not a very scalable solution.

Jon

[bastien1]

The alternative is to configure host names locally on the device you want to ping from ie. on a PC

This last sentence troubles me.

As I said, my layer 2 switch has an hostname configured (and its domain-name is configured).

so I should be able to ping it without any DNS record of it in the DNS server ?

[Jon Marshall]

It is the device you are pinging from that needs to resolve the name to an IP so it doesn't matter what you have done on the switch.

Perhaps I am not understanding your question.

Jon

[bastien1]

No, you understood the question ;)

It's just me who don't understand english very well as it's not my primary language ...

Anyway, I need to map FQDNs on a DNS server before being able to resolve them.

Thank you for your help.

[Jon Marshall]

No problem, glad to have helped.

Jon