Re: Class B, Name lookups? BUG

James L. McGill (fishbowl@pic.net)
Mon, 24 Jun 1996 12:38:52 -0500 (CDT)


-----BEGIN PGP SIGNED MESSAGE-----

Dear Alan Cox, et al:

What follows is hopefully enough information for someone
to understand my networking problem.

I have tried to communicate the fact that I have a firm grasp
of the concepts, and that this SHOULD work, and DOES work on
other (e.g. Sun) systems with no problems. However this failure
seems to apply to Linux, but we don't understand why or what is
wrong.

The problem does not seem to relate to routing. Routing works.
I can reach anything on the internet by IP address.

My DNS servers work fine. Via nslookup they lookup names.
Using a client program (ftp, telnet, traceroute, ping, ssh...)
that needs to lookup a name, they fail. Nothing can lookup
names. At the risk of repeating myself, If I simply plug in
may Net Configuration:

IPADDR=10.2.3.245
NETMASK=255.255.0.0
NETWORK=10.2.0.0
BROADCAST=10.2.255.255
GATEWAY=10.2.1.254

This works on every system I tried except for Linux.
I couldn't get this to work on an out-of-the-box RedHat
or Slackware install, nor on other production boxes,
including virgin 1.2.13 boxes and 2.0.0 machines that
have had "everything" upgraded.

I hope that I have made some simple error and somebody can
point it out. I would not mind feeling stupid %-)
I do feel that I have configured everything completely
and checked everything twice, and I believe this should work.

If you have time to look at this typescript, I've attempted
to prove my dilemma by showing what I've done, and that I've
checked it thoroughly:

Script started on Mon Jun 24 11:59:46 1996

[root@junk /root]# ifconfig eth0
eth0 Link encap:10Mbps Ethernet HWaddr 00:A0:24:56:CC:5C
inet addr:10.2.3.245 Bcast:10.2.255.255 Mask:255.255.0.0
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
RX packets:93 errors:0 dropped:0 overruns:0
TX packets:51 errors:0 dropped:0 overruns:0
Interrupt:10 Base address:0xff80

[root@junk /root]# netstat -rn
Kernel routing table
Destination Gateway Genmask Flags Metric Ref Use Iface
10.2.0.0 0.0.0.0 255.255.0.0 U 0 0 4 eth0
127.0.0.0 0.0.0.0 255.0.0.0 U 0 0 14 lo
0.0.0.0 10.2.1.254 0.0.0.0 UG 0 0 46 eth0

#
# Previously you said there may be a problem with this
# routing table, but......
#
# I can reach hosts on my wire.
#

[root@junk /root]# ping 10.2.3.15
PING 10.2.3.15 (10.2.3.15): 56 data bytes
64 bytes from 10.2.3.15: icmp_seq=0 ttl=64 time=1.9 ms

- --- 10.2.3.15 ping statistics ---
1 packets transmitted, 1 packets received, 0% packet loss
round-trip min/avg/max = 1.9/1.9/1.9 ms

[root@junk /root]# cat/etc/networks
loopback 127.0.0.0
localnet 10.2.0.0

[root@junk /root]# cat /etc/hosts
127.0.0.1 localhost
10.2.3.245 junk.my.network.com junk

[root@junk /root]# cat /etc/host.conf
order hosts,bind
multi on

[root@junk /root]# cat /etc/resolv.conf
domain my.network.com
nameserver 204.58.152.2
nameserver 204.58.152.3

# I can communicate with the Internet, and
# reach my nameservers.

[root@junk /root]# nslookup
Default Server: bilbo.pic.net
Address: 204.58.152.2

> www.whitehouse.gov
Server: bilbo.pic.net
Address: 204.58.152.2

Name: www.whitehouse.gov
Addresses: 198.137.240.92, 198.137.240.91

> exit

# Can even reach hosts on the internet BY IP ADDRESS!

[root@junk /root]# telnet 198.137.240.92 80
Trying 198.137.240.92...
Connected to 198.137.240.92.
Escape character is '^]'.

telnet> quit
Connection closed.
[root@junk /root]# nslookup sunsite.unc.edu
Server: bilbo.pic.net
Address: 204.58.152.2

Non-authoritative answer:
Name: sunsite.unc.edu
Address: 152.2.254.81

[root@junk /root]# ftp 152.2.254.81
Connected to 152.2.254.81.
220 helios FTP server (Version wu-2.4(39) Tue May 16 01:34:21 EDT 1995) ready.
Name (152.2.254.81:root): ftp
331 Guest login ok, send your complete e-mail address as password.
Password:
230 Guest login ok, access restrictions apply.
Remote system type is UNIX.
Using binary mode to transfer files.
ftp> quit
221 Goodbye.

### BUT, I cannot reach hosts by NAME.
###
### ftp sunsite.unc.edu fails. (Just plain doesn't work)

ftp sunsite.unc.edu: Host name lookup failure.

### telnet bilbo.pic.net fails.
### every client to a symbolic address fails the same way.
### It all works wonderfully if I use IP Addresses!
### I have this problem on all Slackware and RedHat boxes.
### No problems of this sort on Solaris, NT, or 95 boxes.
###
### What is going on? Please advise us.

- --
g-r-a-t-e-f-u-l-l-y---[ email:<fishbowl@conservatory.com> ]---l-i-v-i-n-g
d-e-a-d-i-c-a-t-e-d---[ http://www.conservatory.com/~fishbowl ]-----l-i-g-h-t

I've got to fix this before we get "directed" to solve the
problem by changing OS. =:-O

-----BEGIN PGP SIGNATURE-----
Version: 2.6.2i

iQBVAwUBMc7Sr8PTedxmOfz5AQEAhAIAuRTytycLP/1HebhjP1PARMwPnIlsHLUY
7s5qEMODlWC2J+MZmrQAkivHsI6reueVYdNVrtO9H+VbhSz1Ggwv8Q==
=MGYm
-----END PGP SIGNATURE-----