Re: [CentOS] named is up but does not respond to queries

On 8/24/05, Les Mikesell lesmikesell@gmail.com wrote:

On Wed, 2005-08-24 at 10:34, Arun K. Khan wrote:

...

CentOS 4.1/bind-9.2.4-2.

I have named serving as a cache DNS server plus SOA for a local intranet zone.

The problem I am encountering - over a period of time it stops responding to queries.

...

    (from 192.168.1.150)
    $ host www.yahoo.com 192.168.1.21
    ;; connection timed out; no servers could be reached

    # nmapfe of 192.168.1.21  (from 192.168.1.150)
    (The 1208 ports scanned but not shown below are in state:
    closed)
    PORT      STATE SERVICE
    22/tcp    open  ssh
    25/tcp    open  smtp
    53/tcp    open  domain

    (ssh'd into named server using IP# 192.168.1.21)
    # service named status
    rndc: recv failed: operation canceled

It looks like it can't reach the root servers. It has a private address - could you have a problem with your NAT gateway to the internet? How about your local firewalling on 53/udp to let the responses back?

For DNS servers 53/tcp is required as well. UDP handles most requests but when the amount of data is great enough it uses TCP. IIRC yahoo returns quite a few.