Cisco SF300 Layer3 DHCP external DNS problem

[bzahalka]

Hi,

I have set up multiple VLANs on my SF300 and they are working fine. I managed to set up the switch as DHCP server on one of the VLANs. My clients get the right information, they get the correct IP address, correct DNS server addresses, but I could not set them to show in the DNS server at all. As I know, the DHCP server should register the assigned IP address in the DNS server, but in the DNS server's log there are no sign that the switch even tries to do that. In the DNS server my zone is set to be dynamic zone and allowed the switch to register into that zone.

The relevant config lines:

set system mode router

vlan database
vlan 42,50

ip dhcp server
ip dhcp pool network poolname
address low 10.X.Y.1 high 10.X.Y.199 255.255.255.0
domain-name mydomainname
default-router 10.X.Y.254
dns-server DNSAddress1 DNSAddress2
exit

clock timezone " " +2
ip domain name mydomainname
ip name-server DNSAddress1 DNSAddress2

!
interface vlan 50
ip address 10.X.Y.250 255.255.255.0
!

Anyway, on the GUI it is not possible to set all the DNS server address, only 1 can be set. What else should I set to let it register my clients into the DNS? Is there a specific DHCP option for that?

[Kasun Bandara]

i am confused by your say ' As I know, the DHCP server should register the assigned IP address in the DNS server, but in the DNS server's log there are no sign that the switch even tries to do that. '.  but simply for SMB switches like SF300, only one DNS server can set in GUI. but you can use CLI to set more DNS servers by entering one by one with space between them. 

like, 

dns-server 1.1.1.1 8.8.8.8

[bzahalka]

We use our own linux based DNS server. As you can see I already set my own DNS servers in the relevant config lines.

I wish to use the dynamic DNS function. So my client get the IP address from my SF300 and the assigned IP address should be registered in the DNS server. But when we read the log file on the DNS server, there is no sign that the switch even try to do that.

[Kasun Bandara]

what is your product using for DDNS? switch normally not initiating any DDNS mapping actions. it only passes DHCP lease to client. thats all. other tasks need to be done by DDNS server or client PC application

[bzahalka]

We use Novell bind 9.16 for DNS.

[Kasun Bandara · Accepted solution]

I see that is a DNS server. is same software using to do DDNS? if so how it is configured? again. switch is not doing any part of DDNS mappings

[bzahalka]

It is the same. The config line for our zone is this:

zone "myzone"     {type master; file "master/myzone";   allow-update { DNSAddress1; 10.X.Y.250; }; journal "master/myzone.jnl"; max-journal-size 10M; }