[Dnsmasq-discuss] Failed to lookup names randomly

Wang Jian larkwang at gmail.com
Thu May 8 12:47:21 UTC 2014


As I said earlier, I have a dnsmasq setup in a 150 clients environment.  We
are running debian package 2.70-1 built from git.

These few days, we frequently have name lookup failure. I have no
conclusion by now, but I suspect cache code is involved.

A log segment

<colleague A in my team visit this site in browser>
May  8 18:51:30 dnsmasq[22631]: query[A] www.iciba.com from 10.2.3.102
May  8 18:51:30 dnsmasq[22631]: forwarded www.iciba.com to 114.114.114.114
May  8 18:51:30 dnsmasq[22631]: query[A] goto.www.iciba.com from 10.2.3.102
May  8 18:51:30 dnsmasq[22631]: forwarded goto.www.iciba.com to
114.114.114.114
May  8 18:51:30 dnsmasq[22631]: reply www.iciba.com is 58.68.226.32
May  8 18:51:30 dnsmasq[22631]: reply goto.www.iciba.com is <CNAME>
< browser failed to load the page, dns query failed >

<colleague B in my team visit this site by click url provided by A>
May  8 18:52:23 dnsmasq[22631]: query[A] www.iciba.com from 10.2.1.194
May  8 18:52:23 dnsmasq[22631]: forwarded www.iciba.com to 114.114.114.114
May  8 18:52:23 dnsmasq[22631]: reply www.iciba.com is 58.68.226.32

<colleague A tried again>
May  8 18:52:39 dnsmasq[22631]: query[A] www.iciba.com from 10.2.3.102
May  8 18:52:39 dnsmasq[22631]: forwarded www.iciba.com to 114.114.114.114
May  8 18:52:39 dnsmasq[22631]: reply www.iciba.com is 58.68.226.32
<this time page load successfully>

May  8 18:53:03 dnsmasq[22631]: query[A] goto.www.iciba.com from 10.2.3.102
May  8 18:53:03 dnsmasq[22631]: forwarded goto.www.iciba.com to
114.114.114.114
May  8 18:53:03 dnsmasq[22631]: reply goto.www.iciba.com is <CNAME>

<the following is I test from the router itself, by running 'host' and
'dig'>

May  8 19:59:00 dnsmasq[22631]: query[A] www.iciba.com from 10.2.0.1
May  8 19:59:00 dnsmasq[22631]: forwarded www.iciba.com to 114.114.114.114
May  8 19:59:00 dnsmasq[22631]: reply www.iciba.com is 58.68.226.32
May  8 19:59:04 dnsmasq[22631]: query[A] www.iciba.com from 10.2.0.1
May  8 19:59:04 dnsmasq[22631]: forwarded www.iciba.com to 114.114.114.114
May  8 19:59:04 dnsmasq[22631]: reply www.iciba.com is 58.68.226.32
May  8 19:59:06 dnsmasq[22631]: query[A] www.iciba.com from 10.2.0.1
May  8 19:59:06 dnsmasq[22631]: cached www.iciba.com is 58.68.226.32
May  8 19:59:08 dnsmasq[22631]: query[A] www.iciba.com from 10.2.0.1
May  8 19:59:08 dnsmasq[22631]: cached www.iciba.com is 58.68.226.32
May  8 19:59:12 dnsmasq[22631]: query[A] www.iciba.com from 10.2.0.1
May  8 19:59:12 dnsmasq[22631]: cached www.iciba.com is 58.68.226.32
May  8 19:59:13 dnsmasq[22631]: query[A] www.iciba.com from 10.2.0.1
May  8 19:59:13 dnsmasq[22631]: cached www.iciba.com is 58.68.226.32
May  8 19:59:15 dnsmasq[22631]: query[A] www.iciba.com from 10.2.0.1
May  8 19:59:15 dnsmasq[22631]: cached www.iciba.com is 58.68.226.32
May  8 20:00:22 dnsmasq[22631]: query[A] www.iciba.com from 10.2.0.1
May  8 20:00:22 dnsmasq[22631]: forwarded www.iciba.com to 114.114.114.114
May  8 20:00:22 dnsmasq[22631]: reply www.iciba.com is 58.68.226.32


The last 8  'dig' return (look at the TTL)

www.iciba.com.          557     IN      A       58.68.226.32
www.iciba.com.          552     IN      A       58.68.226.32
www.iciba.com.          550     IN      A       58.68.226.32
www.iciba.com.          548     IN      A       58.68.226.32
www.iciba.com.          544     IN      A       58.68.226.32
www.iciba.com.          543     IN      A       58.68.226.32
www.iciba.com.          541     IN      A       58.68.226.32
www.iciba.com.          475     IN      A       58.68.226.32



The following is earlier log I lookup a name from the router when given a
unresolvable name.


root at b10gw:~# host en.cppreference.com
Host en.cppreference.com not found: 2(SERVFAIL)
root at b10gw:~# host en.cppreference.com
Host en.cppreference.com not found: 2(SERVFAIL)
root at b10gw:~# host en.cppreference.com 8.8.8.8
Using domain server:
Name: 8.8.8.8
Address: 8.8.8.8#53
Aliases:

en.cppreference.com has address 74.114.88.128
root at b10gw:~# host en.cppreference.com
Host en.cppreference.com not found: 2(SERVFAIL)
root at b10gw:~# host en.cppreference.com
en.cppreference.com has address 74.114.88.128
root at b10gw:~# host en.cppreference.com
en.cppreference.com has address 74.114.88.128
root at b10gw:~# host en.cppreference.com
en.cppreference.com has address 74.114.88.128
root at b10gw:~# host en.cppreference.com
en.cppreference.com has address 74.114.88.128
root at b10gw:~# host en.cppreference.com
en.cppreference.com has address 74.114.88.128
root at b10gw:~# host en.cppreference.com
en.cppreference.com has address 74.114.88.128



May  8 17:49:15 dnsmasq[17390]: query[A] en.cppreference.com from 10.2.0.1
May  8 17:49:15 dnsmasq[17390]: forwarded en.cppreference.com to
114.114.114.114
May  8 17:49:15 dnsmasq[17390]: reply en.cppreference.com is 74.114.88.128
May  8 17:49:15 dnsmasq[17390]: query[A] en.cppreference.com from 10.2.0.1
May  8 17:49:15 dnsmasq[17390]: forwarded en.cppreference.com to
114.114.114.114
May  8 17:49:15 dnsmasq[17390]: reply en.cppreference.com is 74.114.88.128
May  8 17:49:17 dnsmasq[17390]: query[A] en.cppreference.com from 10.2.0.1
May  8 17:49:17 dnsmasq[17390]: forwarded en.cppreference.com to
114.114.114.114
May  8 17:49:17 dnsmasq[17390]: reply en.cppreference.com is 74.114.88.128
May  8 17:49:17 dnsmasq[17390]: query[A] en.cppreference.com from 10.2.0.1
May  8 17:49:17 dnsmasq[17390]: forwarded en.cppreference.com to
114.114.114.114
May  8 17:49:17 dnsmasq[17390]: reply en.cppreference.com is 74.114.88.128
May  8 17:49:24 dnsmasq[17390]: query[A] en.cppreference.com from 10.2.0.1
May  8 17:49:24 dnsmasq[17390]: forwarded en.cppreference.com to
114.114.114.114
May  8 17:49:24 dnsmasq[17390]: reply en.cppreference.com is 74.114.88.128
May  8 17:49:24 dnsmasq[17390]: query[A] en.cppreference.com from 10.2.0.1
May  8 17:49:24 dnsmasq[17390]: forwarded en.cppreference.com to
114.114.114.114
May  8 17:49:24 dnsmasq[17390]: reply en.cppreference.com is 74.114.88.128
May  8 17:49:26 dnsmasq[17390]: query[A] en.cppreference.com from 10.2.0.1
May  8 17:49:26 dnsmasq[17390]: forwarded en.cppreference.com to
114.114.114.114
May  8 17:49:26 dnsmasq[17390]: reply en.cppreference.com is 74.114.88.128
May  8 17:49:26 dnsmasq[17390]: query[AAAA] en.cppreference.com from
10.2.0.1
May  8 17:49:26 dnsmasq[17390]: forwarded en.cppreference.com to
114.114.114.114
May  8 17:49:26 dnsmasq[17390]: reply en.cppreference.com is NODATA-IPv6
May  8 17:49:26 dnsmasq[17390]: query[MX] en.cppreference.com from 10.2.0.1
May  8 17:49:26 dnsmasq[17390]: forwarded en.cppreference.com to
114.114.114.114
May  8 17:49:27 dnsmasq[17390]: query[A] en.cppreference.com from 10.2.0.1
May  8 17:49:27 dnsmasq[17390]: cached en.cppreference.com is 74.114.88.128
May  8 17:49:27 dnsmasq[17390]: query[AAAA] en.cppreference.com from
10.2.0.1
May  8 17:49:27 dnsmasq[17390]: cached en.cppreference.com is NODATA-IPv6
May  8 17:49:27 dnsmasq[17390]: query[MX] en.cppreference.com from 10.2.0.1
May  8 17:49:27 dnsmasq[17390]: forwarded en.cppreference.com to
114.114.114.114
May  8 17:49:32 dnsmasq[17390]: query[A] en.cppreference.com from 10.2.0.1
May  8 17:49:32 dnsmasq[17390]: forwarded en.cppreference.com to
114.114.114.114
May  8 17:49:32 dnsmasq[17390]: reply en.cppreference.com is 74.114.88.128
May  8 17:49:32 dnsmasq[17390]: query[AAAA] en.cppreference.com from
10.2.0.1
May  8 17:49:32 dnsmasq[17390]: forwarded en.cppreference.com to
114.114.114.114
May  8 17:49:32 dnsmasq[17390]: reply en.cppreference.com is NODATA-IPv6
May  8 17:49:32 dnsmasq[17390]: query[MX] en.cppreference.com from 10.2.0.1
May  8 17:49:32 dnsmasq[17390]: forwarded en.cppreference.com to
114.114.114.114
May  8 17:49:33 dnsmasq[17390]: query[A] en.cppreference.com from 10.2.0.1
May  8 17:49:33 dnsmasq[17390]: forwarded en.cppreference.com to
114.114.114.114
May  8 17:49:33 dnsmasq[17390]: reply en.cppreference.com is 74.114.88.128
May  8 17:49:33 dnsmasq[17390]: query[AAAA] en.cppreference.com from
10.2.0.1
May  8 17:49:33 dnsmasq[17390]: forwarded en.cppreference.com to
114.114.114.114
May  8 17:49:33 dnsmasq[17390]: reply en.cppreference.com is NODATA-IPv6
May  8 17:49:33 dnsmasq[17390]: query[MX] en.cppreference.com from 10.2.0.1
May  8 17:49:33 dnsmasq[17390]: forwarded en.cppreference.com to
114.114.114.114
May  8 17:49:33 dnsmasq[17390]: query[A] en.cppreference.com from 10.2.1.194
May  8 17:49:33 dnsmasq[17390]: cached en.cppreference.com is 74.114.88.128
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