sorry i mixed two things. - u say: Then the funny thing is why is the firewall blocking that "answer" :-? - me: no, the router is not blocking the answer, it return an answer for your querry [SRC=192.168.1.12 DST=128.9.0.107 LEN=62 TOS=0x00 PREC=0x00 TTL=64 ID=61490 DF PROTO=UDP SPT=2529 DPT=53 LEN=42 ], saying "i can't talk to DNS SERVER" not reach (128.9.0.107) yes is the firewall who blocks the packet because: - u say: No... the packet itself is not going to port 53, it is icmp protocol. Then why is it blocked? - me: that log is not for a block of an output packet, is an information for a blocked packet of an answer. i explained, the iptables blocked an icmp packet because u don't querry that, u send and udp querry asking for a dns resolv and u wait an udp answer, but not an icmp. :p sorry :p agr.suzdal escribió:
- u say: Then the funny thing is why is the firewall blocking that "answer" :-? - me: no, the router is not blocking the answer, it return an answer for your querry [SRC=192.168.1.12 DST=128.9.0.107 LEN=62 TOS=0x00 PREC=0x00 TTL=64 ID=61490 DF PROTO=UDP SPT=2529 DPT=53 LEN=42 ], saying "i can't talk to DNS SERVER" not reach (128.9.0.107)
- u say: Perhaps I should open the firewall to port 53, which currently is not, as I don't serve dns queries
- me: one question - why you installed the bind pack? why u need it? only is needed when you want a dns server, but isn't a common uses for a normal/common user, however in most cases, you don't need it for navigate thru Internet. With a dns server's ip on resolv.conf is enough for that purpose and only is needed bind-utils-9.3.2-56.3 - (Utilities to query and test DNS) and bind-libs-9.3.2-56.3 - (Shared libraries of BIND).
u only need to open de 53 port when you want to serve dns to each other (lan,wan,internet, etc...).
- u say: No... the packet itself is not going to port 53, it is icmp protocol. Then why is it blocked? - me: that log is not for a block of an output packet, is an information for a blocked packet of an answer. i explained, the iptables blocked an icmp packet because u don't querry that, u send and udp querry asking for a dns resolv and u wait an udp answer, but not an icmp.
Chejov Suzdal www.hacktimes.com www.qualias.net
Carlos E. R. escribió:
The Thursday 2008-01-17 at 22:24 +0100, agr.suzdal wrote:
i think that something on your computer is going down.
first: 128.9.0.107 = ns1.isi.edu
Yes.
and it's a root name server of DNS as you can see at http://en.wikipedia.org/wiki/Root_nameserver
I guessed so, but didn't know how to make sure.
; formerly NS1.ISI.EDU ; . 3600000 NS B.ROOT-SERVERS.NET. B.ROOT-SERVERS.NET. 3600000 A 128.9.0.107
second: icmp type 3 code 0 = Host Unreachable
Ah!
third: as you can see at logs, your ROUTER (SRC=192.168.1.1) is sending a packet to you (DST=192.168.1.12)
Right, so far I knew :-)
answering "with" Host Unreachable (PROTO=ICMP TYPE=3 CODE=0)
And that I did not know.
that a packet DNS from YOU (SRC) [SRC=192.168.1.12 DST=128.9.0.107 LEN=62 TOS=0x00 PREC=0x00 TTL=64 ID=61490 DF PROTO=UDP SPT=2529 DPT=53 LEN=42 ] can't reach destination.
Ah... ok.
Then the funny thing is why is the firewall blocking that "answer" :-?
Perhaps I should open the firewall to port 53, which currently is not, as I don't serve dns queries :-? No... the packet itself is not going to port 53, it is icmp protocol.
Then why is it blocked?
my recomendation, verify your set of DNS at /etc/resolv.conf, and if it's right, then something is bad onto your computer.
I think there must be something fishy in the hints file, which is the one that suse supplies:
nimrodel:/var/lib/named # rpm -q -f /var/lib/named/root.hint bind-9.4.1.P1-12
But the version is too old:
; last update: Jan 29, 2004 ; related version of root zone: 2004012900
Ok, I got the new version from ftp://ftp.internic.net/domain/named.root, and there is no server at "128.9.0.107" (not in the suse version, not in the new version):
; formerly NS1.ISI.EDU ; . 3600000 NS B.ROOT-SERVERS.NET. B.ROOT-SERVERS.NET. 3600000 A 192.228.79.201
But that's the same data the suse version contains. The only difference is:
nimrodel:/var/lib/named # diff root.hint /home/cer/named.root 12,13c12,13 < ; last update: Jan 29, 2004 < ; related version of root zone: 2004012900 ---
; last update: Nov 01, 2007 ; related version of root zone: 2007110100 74c74 < L.ROOT-SERVERS.NET. 3600000 A 198.32.64.12
L.ROOT-SERVERS.NET. 3600000 A 199.7.83.42
If there is no longer a root server at NS1.ISI.EDU, why is my machine querying it?
At least, replacing the old hints file solves a problem I saw in the logs:
Jan 9 04:21:39 nimrodel named[4688]: checkhints: L.ROOT-SERVERS.NET/A (199.7.83.42) missing from hints Jan 9 04:21:39 nimrodel named[4688]: checkhints: L.ROOT-SERVERS.NET/A (198.32.64.12) extra record in hints
But yet, I nothing related to that 128.9.0.107. I'll grep for it... bingo! I had an old 'root.cache' with that entry, not belonging to any rpm.
You are right, my whole config is fishy; I think I have it right now.
-- Cheers, Carlos E. R.
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