,Re: caching does not seem to be working for internal view

[Robert Moskowitz]

On 8/3/22 11:35, Timothe Litt wrote:
> On 03-Aug-22 10:53, bind-users-request at lists.isc.org wrote:
>> # cat resolv.conf
>>
>> My server is 23.123.122.146.  That IPv6 addr is my ATT router.
>
>
> You don't want to do that.  The ATT router will not know how to 
> resolve internal names.  There is no guarantee that your client 
> resolver will try nameservers in order.  If you want a backup, run a 
> second instance of named.
>
> As for the intermittent issues with resolving external names, that's 
> frequently a case of hitting different nameservers.  Or a firewall.
>
> Get rid of the ATT router first.  Then as suggested, a packet trace 
> will show what happens (if it still does - it could be that the ATT 
> router's resolver is at fault).
>

Thank you for your advice.  my ifcfg-eth0 has:

DEVICE="eth0"
BOOTPROTO=none
ONBOOT="yes"
TYPE="Ethernet"
NAME="eth0"
MACADDR=02:67:15:00:00:02
MTU=1500
DNS1=23.123.122.146
GATEWAY="23.123.122.158"
IPADDR="23.123.122.146"
NETMASK="255.255.255.240"
IPV6INIT="yes"

And I am ASSuMEing that it is that IPV6INIT that is providing that IPv6 
addr in resolv.cat.  So I added:

DNS2=192.168.224.2

And now:

# cat /etc/resolv.conf
# Generated by NetworkManager
search attlocal.net htt-consult.com
nameserver 23.123.122.146
nameserver 192.168.224.2
nameserver 2600:1700:9120:4330::1

ARGH!

I want the IPv6 addr from my firewall/gateway.  But I don't want that 
IPv6 nameserver!

So I added the IPv6 address for my server.  I had not done this as ATT 
has said there is no assurance with the IPv6 addresses may change.  So I 
added:

DNS3=2600:1700:9120:4330::49

and now:

# cat /etc/resolv.conf
# Generated by NetworkManager
search attlocal.net htt-consult.com
nameserver 23.123.122.146
nameserver 192.168.224.2
nameserver 2600:1700:9120:4330::1
# NOTE: the libc resolver may not support more than 3 nameservers.
# The nameservers listed below may not be recognized.
nameserver 2600:1700:9120:4330::49

Sigh.  I have to take that dynamic IPv6 assignment.  But I want to stop 
it pushing into my resolv.conf.