topic Re: dhcpd dns did not assign to client in Network Security

dhcpd dns did not assign to client

lcaruso — Mon, 11 Mar 2019 19:34:32 GMT

On a ASA 5505 8.2(3), the dhcpd dns command did not assign a dns server to the client when configured as such

dhcpd address 10.3.2.100-10.3.2.131 inside

dhcpd dns resolver1.opendns.com interface outside

dhcpd lease 172800 interface inside
dhcpd domain monroe.local interface inside
dhcpd option 3 ip asa-inside interface inside
dhcpd enable inside

It wasn't until I put in this command that the client actually got the dns server address

dhcpd option 6 ip resolver1.opendns.com

Is option 6 the same command as dhcpd dns? Any reason why the dhcpd dns command did not work with the above config?

Thanks.

Re: dhcpd dns did not assign to client

Jitendriya Athavale — Thu, 13 Jan 2011 09:19:15 GMT

yeah optoin 6 is for dns

the reason it didnt work is because of this i guess

dhcpd dns resolver1.opendns.com interface outside

the interface you have specified is outside and i guess your clients rae in inside trying to get ip address and dns server so change it to inside

dhcpd dns resolver1.opendns.com interface inside

Re: dhcpd dns did not assign to client

lcaruso — Thu, 13 Jan 2011 14:35:52 GMT

yeah optoin 6 is for dns

the reason it didnt work is because of this i guess

dhcpd dns resolver1.opendns.com interface outside

the interface you have specified is outside and i guess your clients rae in inside trying to get ip address and dns server so change it to inside

dhcpd dns resolver1.opendns.com interface inside

The only problem is that dns server is on the outside: name 208.67.222.222 resolver1.opendns.com

That's why I referenced outside.

So what you are saying is that dhcpd dns is only for inside servers, whereas option 6 works no matter where it is. Is that correct?

Re: dhcpd dns did not assign to client

Jitendriya Athavale — Thu, 13 Jan 2011 15:36:58 GMT

Its just about on which interface to send these value when a request comes from a particular interface

So you have configured it such that if the dhcp request comes on outside interface it will respond with that value, so if you change the interface to inside it should work irrespective of where the dns server is, all this command does is provides the value of dns server to query requests

Regards,

Jitendriya

Re: dhcpd dns did not assign to client

lcaruso — Thu, 13 Jan 2011 15:41:07 GMT

Thank you kindly.

I must be working too much

Re: dhcpd dns did not assign to client

Jitendriya Athavale — Thu, 13 Jan 2011 15:43:50 GMT

glad that I could be of help

Regards,

Jitendriya