Re: Strange DNS problem

2019-06-10 Thread Mark Andrews
You solve that by complaining to the operators of the servers that their DNS servers mis-implement DNS COOKIE (RFC 7873) and could they request a fix from their DNS vendor. Not that they make things easy to contact them. No email in whois. Just a PO box and a phone number and I don’t intend to

Re: BIND ignores queries from specific privileged source ports

2019-06-10 Thread Grant Taylor via bind-users
On 6/10/19 3:29 PM, Mark Andrews wrote: The primary issue here is that there is still source address spoofing happening so you have to consider what if this packet was spoofed. DNS uses UDP and is used as a reflector. The small services ports listed generate reply traffic. Additionally

Re: BIND ignores queries from specific privileged source ports

2019-06-10 Thread Mark Andrews
The primary issue here is that there is still source address spoofing happening so you have to consider what if this packet was spoofed. DNS uses UDP and is used as a reflector. The small services ports listed generate reply traffic. Additionally kpasswd and a DNS server can generate a self

Re: BIND ignores queries from specific privileged source ports

2019-06-10 Thread Warren Kumari
On Mon, Jun 10, 2019 at 12:37 PM Grant Taylor via bind-users wrote: > > On 6/7/19 8:44 PM, Mark Andrews wrote: > > Named drops those ports as they can be used in reflection attacks. > > Sane NAT developers avoid those ports for just that reason. The full > > list is below. > > I understand the

Re: BIND ignores queries from specific privileged source ports

2019-06-10 Thread Mark Andrews
> On 11 Jun 2019, at 8:01 am, Grant Taylor via bind-users > wrote: > > On 6/10/19 3:29 PM, Mark Andrews wrote: >> The primary issue here is that there is still source address spoofing >> happening so you have to consider what if this packet was spoofed. DNS uses >> UDP and is used as a

Re: BIND ignores queries from specific privileged source ports

2019-06-10 Thread Grant Taylor via bind-users
On 6/10/19 4:56 PM, Mark Andrews wrote: Named is already selective about what it doesn’t reply to. * Packets < 12 octets (DNS header size) don’t get a reply. * QR=1 doesn’t get a reply. * Source port 0 doesn’t get a reply (source port 0 is “discard me”). * Kpasswd doesn’t get FORMERR. * echo,

Strange DNS problem

2019-06-10 Thread Jukka Pakkanen
We have a strange problem related to DNS services, maybe someone here have a clue what could be the problem. We are running BIND 9.14.2 in several servers, ns1.qnet.fi, ns2.qnet.fi etc. Everything else works fine, but with one small operator (actually a mediahouse), we can not get any replies

Re: Strange DNS problem

2019-06-10 Thread Stephane Bortzmeyer
On Mon, Jun 10, 2019 at 02:28:46PM +, Jukka Pakkanen wrote a message of 382 lines which said: > An example, the client domain is raimoasikainenoy.fi. dig clearly says it's a cookie issue: % dig @193.184.54.212 NS raimoasikainenoy.fi ;; Warning: Client COOKIE mismatch An DNSviz

Re: Strange DNS problem

2019-06-10 Thread Chris Thompson
On Jun 10 2019, Jukka Pakkanen wrote: We have a strange problem related to DNS services, maybe someone here have a clue what could be the problem. […] An example, the client domain is raimoasikainenoy.fi. Well, there is certainly something wrong with ns.datatower.fi [193.184.54.212], as it

Re: BIND ignores queries from specific privileged source ports

2019-06-10 Thread Blake Hudson
Thank you Mark. A popular NAT appliance manufacturer has some logic that attempts to keep the translated source port close to the untranslated source port which can sometimes result in the behavior I've described where DNS queries use the well known source port of protocols that are abuse

RE: Strange DNS problem

2019-06-10 Thread Jukka Pakkanen
-Original Message- From: Chris Thompson On Behalf Of Chris Thompson Sent: 10. kesäkuuta 2019 17:30 To: Jukka Pakkanen Cc: bind-us...@isc.org Subject: Re: Strange DNS problem On Jun 10 2019, Jukka Pakkanen wrote: >We have a strange problem related to DNS services, maybe someone here

RE: Strange DNS problem

2019-06-10 Thread Jukka Pakkanen
-Original Message- From: Chris Thompson On Behalf Of Chris Thompson Sent: 10. kesäkuuta 2019 17:30 To: Jukka Pakkanen Cc: bind-us...@isc.org Subject: Re: Strange DNS problem On Jun 10 2019, Jukka Pakkanen wrote: >We have a strange problem related to DNS services, maybe someone here

Re: BIND ignores queries from specific privileged source ports

2019-06-10 Thread Grant Taylor via bind-users
On 6/10/19 10:18 AM, Barry Margolin wrote: Why would the original source port be close to any of these low port numbers? Source ports should normally be ephemeral ports. There has been some movement afoot in the last 10 years or so to use more of the 65,535 ports as the source port for

Re: BIND ignores queries from specific privileged source ports

2019-06-10 Thread Barry Margolin
In article , Blake Hudson wrote: > Thank you Mark. A popular NAT appliance manufacturer has some logic that > attempts to keep the translated source port close to the untranslated > source port which can sometimes result in the behavior I've described > where DNS queries use the well known

Re: BIND ignores queries from specific privileged source ports

2019-06-10 Thread Grant Taylor via bind-users
On 6/7/19 8:44 PM, Mark Andrews wrote: Named drops those ports as they can be used in reflection attacks. Sane NAT developers avoid those ports for just that reason. The full list is below. I understand the logic behind avoiding potentially problematic ports. But I don't understand the

Re: Strange DNS problem

2019-06-10 Thread Stephane Bortzmeyer
On Mon, Jun 10, 2019 at 05:43:02PM +, Jukka Pakkanen wrote a message of 58 lines which said: > Then, unfortunately our nameservers won't resolve ns.kpk.fi either. Same authoritative name server, same problem. See my email. % dig @ns.datatower.fi. NS kpk.fi. ;; Warning: Client COOKIE

RE: Strange DNS problem

2019-06-10 Thread Jukka Pakkanen
Yeah, another advertising company turned to an ISP... Solved *our* problem now by including the suggested server clause for both of their broken servers, to our servers. Of course does not solve the real problem, the broken servers of theirs. Thanks for help. Jukka -Original