[plug] Misconfiguration on server tcp/routing
Tim White
weirdit at gmail.com
Thu Feb 25 07:24:27 WST 2010
Check for static routes on both your box and the router.
(type in route -n on your box, on the router, it'll usually be a config
page)
And just to show you that your DNS is working... The reason it goes to a
different hostname is due to how DNS works with load balancing. We get a
CNAME which then points to multiple ip address which alternate round
robin style. Try for yourself running (dig www.google.com a few times)
$ ping www.google.com
PING www.l.google.com (66.102.11.99) 56(84) bytes of data.
64 bytes from syd01s01-in-f99.1e100.net (66.102.11.99): icmp_seq=1
ttl=56 time=73.1 ms
64 bytes from syd01s01-in-f99.1e100.net (66.102.11.99): icmp_seq=2
ttl=56 time=72.8 ms
64 bytes from syd01s01-in-f99.1e100.net (66.102.11.99): icmp_seq=3
ttl=56 time=73.2 ms
64 bytes from syd01s01-in-f99.1e100.net (66.102.11.99): icmp_seq=4
ttl=56 time=72.7 ms
^C
--- www.l.google.com ping statistics ---
4 packets transmitted, 4 received, 0% packet loss, time 3004ms
rtt min/avg/max/mdev = 72.759/73.017/73.271/0.290 ms
Tim
On 24/02/10 22:16, Lucas van Staden wrote:
> Hi,
>
> Been a few days since I could spend time to look at this again, and
> unfortunately, the issue is not solved.
> I think, to begin with, I had two issues, one of which was DNS, which
> is solved.
>
> The resolv.conf is now pointing directly to iinet's dns servers:
> web at webserver:~$ cat /etc/resolv.conf
> nameserver 203.0.178.191
> nameserver 203.215.29.191
>
> For some reason it looks like any request to google (and a couple of
> other ip's/domains) seem to route back to my own box.
> I am sure this must be a configuration issue on the router, but I
> could be wrong.
> I have not had the time to replace this router. (it is in fact a
> replacement of a belkin on which the wireless stopped working)
>
> web at webserver:~$ ping www.google.com
> PING www.l.google.com (66.102.11.104) 56(84) bytes of data. <--- DNS
> does resolve
> From 192.168.0.6 icmp_seq=1 Destination Port Unreachable
> From 192.168.0.6 icmp_seq=2 Destination Port Unreachable
> From 192.168.0.6 icmp_seq=3 Destination Port Unreachable
>
> web at webserver:~$ ping 66.102.11.104 <-- can't ping ip even directly
> PING 66.102.11.104 (66.102.11.104) 56(84) bytes of data.
> From 192.168.0.6 icmp_seq=1 Destination Port Unreachable
> From 192.168.0.6 icmp_seq=2 Destination Port Unreachable
> From 192.168.0.6 icmp_seq=3 Destination Port Unreachable
>
> And a server in the UK:
>
> web at webserver:~$ ping www.lizearle.com
> PING lizearle.com (217.72.240.223) 56(84) bytes of data.
> 64 bytes from 217.72.240.223: icmp_seq=1 ttl=114 time=414 ms
> 64 bytes from 217.72.240.223: icmp_seq=2 ttl=114 time=414 ms
> 64 bytes from 217.72.240.223: icmp_seq=3 ttl=114 time=403 ms
> ^C
> --- lizearle.com ping statistics ---
> 4 packets transmitted, 3 received, 25% packet loss, time 3022ms
> rtt min/avg/max/mdev = 403.980/411.103/414.926/5.041 ms
>
> which works fine.
>
> As mentioned, I can browse them via links, from the same box, and
> there is no proxy involved.
>
>
> Any ideas what I should be looking for?
>
> -Lucas
>
>
> Tim White wrote:
>> I've had no problems with Billion in the last few years.
>>
>> Recently had similar issues with DNS on a router, think it was a
>> netgear but can't remember. Apparently it's to do with IPv6 causing
>> issues, and seeing as most Windoze clients don't have IPv6 on by
>> default, the fault wasn't apparent except under Linux. My solution,
>> run dnsmasq and/or set to always use ISP or another providers DNS
>> servers. (I used googles new public dns servers so it works from any
>> location, as this was on my laptop and some ISP's limit connection to
>> their DNS servers to their customers. Plus 8.8.8.8 and 8.8.4.4 are
>> easy to remember, even if they aren't located in Australia).
>>
>> Tim
>>
>> On 20/02/10 13:20, Lucas van Staden wrote:
>>> Hi Peter, thank you for the reply.
>>>
>>> I have also started to realise this could be DNS.
>>> Further investigation also shows mails are defered (using exim)
>>>
>>> R: dnslookup_relay_to_domains for lucas at vanstaden.com.au
>>> calling dnslookup_relay_to_domains router
>>> dnslookup_relay_to_domains router called for lucas at vanstaden.com.au
>>> domain = vanstaden.com.au
>>> DNS lookup of vanstaden.com.au (MX) gave TRY_AGAIN
>>> vanstaden.com.au in dns_again_means_nonexist? no (option unset)
>>> returning DNS_AGAIN
>>> dnslookup_relay_to_domains router: defer for lucas at vanstaden.com.au
>>> message: host lookup did not complete
>>> lucas at vanstaden.com.au cannot be resolved at this time: host lookup
>>> did not complete
>>> search_tidyup called
>>>
>>>
>>> The router is the main dns server for the internal network, all
>>> machines are xp desktops, except for this server)
>>> Manual configuration. No network manager stuff installed.
>>>
>>> web at webserver:~$ cat /etc/resolv.conf
>>> nameserver 192.168.0.1
>>>
>>> There are no other dns servers on this network. (should not be anyways)
>>>
>>> dns on the router:
>>>
>>> # cat /etc/resolv.conf
>>> nameserver 203.0.178.191
>>> nameserver 203.215.29.191
>>>
>>> Pings etc from the router itself is fine.
>>>
>>> Taking the nameserver from the router to the server, fixes the issue.
>>>
>>> So, the issue is with the routers dns server? (d-link g604t)
>>>
>>> Already planning on dumping this router, as it is constantly hanging.
>>>
>>> Any sugegstions on a mid-range decent router, which can at least
>>> handle a bit of intense network trafic?
>>> This is now the second d-link in 6 months I have had issues with.
>>> Looks like d-link will go off my list of brands to buy.
>>>
>>> -Lucas
>>>
>>>
>>>
>>> Peter wrote:
>>>> Lucas van Staden wrote:
>>>>> Hello.
>>>>>
>>>>> I have found an odd problem on my webserver box (use purely to
>>>>> just host my own two personal websites)
>>>>>
>>>>> I cannot seem to ping certain addresses, but browsing them from
>>>>> links, works fine.
>>>>> Some work fine.
>>>>> For the life of me I cannot find what is wrong.
>>>>> Other machines on this network works fine.
>>>>> I am sure it is something obvious, but I just can't see it.
>>>>>
>>>>> web at webserver:~$ ping www.google.com
>>>>> PING www.l.google.com (66.102.11.104) 56(84) bytes of data.
>>>>> From 192.168.0.6 icmp_seq=1 Destination Port Unreachable
>>>>>
>>>>> (takes about 1-2 minutes for that response, and for each thereafter)
>>>>>
>>>>> Network setup:
>>>>>
>>>>> auto eth1
>>>>> iface eth1 inet static
>>>>> address 192.168.0.6
>>>>> netmask 255.255.255.0
>>>>> gateway 192.168.0.1
>>>>> network 192.168.0.0
>>>>> broadcast 192.168.0.255
>>>>>
>>>>> web at webserver:~$ sudo route -n
>>>>> [sudo] password for web:
>>>>> Kernel IP routing table
>>>>> Destination Gateway Genmask Flags Metric
>>>>> Ref Use Iface
>>>>> 192.168.0.0 0.0.0.0 255.255.255.0 U 0
>>>>> 0 0 eth1
>>>>> 0.0.0.0 192.168.0.1 0.0.0.0 UG 100
>>>>> 0 0 eth1
>>>>>
>>>>> web at webserver:~$ sudo ifconfig
>>>>> eth1 Link encap:Ethernet HWaddr 00:13:8f:a3:cd:e1
>>>>> inet addr:192.168.0.6 Bcast:192.168.0.255 Mask:255.255.255.0
>>>>> inet6 addr: fe80::213:8fff:fea3:cde1/64 Scope:Link
>>>>> UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
>>>>> RX packets:13720 errors:0 dropped:0 overruns:0 frame:0
>>>>> TX packets:18280 errors:0 dropped:0 overruns:0 carrier:0
>>>>> collisions:0 txqueuelen:1000
>>>>> RX bytes:4039608 (4.0 MB) TX bytes:16416771 (16.4 MB)
>>>>> Interrupt:20 Base address:0xd800
>>>>>
>>>>> lo Link encap:Local Loopback inet addr:127.0.0.1
>>>>> Mask:255.0.0.0
>>>>> inet6 addr: ::1/128 Scope:Host
>>>>> UP LOOPBACK RUNNING MTU:16436 Metric:1
>>>>> RX packets:434 errors:0 dropped:0 overruns:0 frame:0
>>>>> TX packets:434 errors:0 dropped:0 overruns:0 carrier:0
>>>>> collisions:0 txqueuelen:0
>>>>> RX bytes:65165 (65.1 KB) TX bytes:65165 (65.1 KB)
>>>>>
>>>>> web at webserver:~$ traceroute www.google.com
>>>>> traceroute to www.google.com (66.102.11.104), 30 hops max, 40 byte
>>>>> packets
>>>>> 1 (192.168.0.6) 0.090 ms 0.038 ms 0.034 ms
>>>>>
>>>>> Does not go any further
>>>>>
>>>>> I new d-link modem/router has been put in use, and I am unsure if
>>>>> this issue existed before then.
>>>>>
>>>>> Routing on the router:
>>>>>
>>>>> # route -n
>>>>> Kernel IP routing table
>>>>> Destination Gateway Genmask Flags Metric
>>>>> Ref Use Iface
>>>>> 203.59.14.16 203.59.48.28 255.255.255.255 UGH 0
>>>>> 0 0 ppp0
>>>>> 203.59.14.16 0.0.0.0 255.255.255.255 UH 0
>>>>> 0 0 ppp0
>>>>> 203.59.48.28 127.0.0.1 255.255.255.255 UGH 0
>>>>> 0 0 lo
>>>>> 192.168.0.0 192.168.0.1 255.255.255.0 UG 0
>>>>> 0 0 br0
>>>>> 192.168.0.0 0.0.0.0 255.255.255.0 U 0
>>>>> 0 0 br0
>>>>> 239.0.0.0 0.0.0.0 255.0.0.0 U 1
>>>>> 0 0 br0
>>>>> 0.0.0.0 203.59.14.16 0.0.0.0 UG 0
>>>>> 0 0 ppp0
>>>>>
>>>>>
>>>>> What could be wrong?
>>>>>
>>>> Hi Lucas,
>>>>
>>>> Looks like a DNS issue to me. Is the server running DNS (bind)?
>>>> Do you have another DNS server on your network or is your
>>>> modem/router configured to supply DNS info?
>>>>
>>>> What are the DNS settings you are using on the server (Network
>>>> Manager?).... Auto or manual DNS?
>>>>
>>>> What does /etc/resolv.conf look like?
>>>>
>>>> -Peter.
>>>
>>>
>>
>
>
More information about the plug
mailing list