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

[Robert Moskowitz]

On 8/3/22 12:59, Timothe Litt wrote:
>
> Try
>
> echo -e "[main]\ndns=none" > /etc/NetworkManager/conf.d/no-dns.conf
> systemctl restart NetworkManager.service
>

Same content in resolv.conf.  BTW this is on Centos7.

> Timothe Litt
> ACM Distinguished Engineer
> --------------------------
> This communication may not represent the ACM or my employer's views,
> if any, on the matters discussed.
> On 03-Aug-22 12:36, Robert Moskowitz wrote:
>>
>>
>> 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.
>>
>