Hi, Gurus,
I have just installed Solaris 10 on a Dell PC behind a Linksys router, and did the following tcp/ip configuration. All seems OK except DNS does not work out right:
1. Created a S99tcpip script in the /etc/rc3.d directory, which works OK:
#! /sbin/sh
case "$1" in
start)
/sbin/ifconfig elxl0 plumb
/sbin/ifconfig elxl0 192.168.1.90 netmask 255.255.255.0
/sbin/ifconfig elxl0 up
/sbin/route add default 192.168.1.1
# 192.168.1.1 is the Linksys router.
;;
stop)
:
;;
*)
echo "Usage: $0 { start | stop }"
exit 1
;;
esac
exit 0
So with this script, after booting up, I checked and got the following:
$ ifconfig -a
lo0: flags=2001000849<UP,LOOPBACK,RUNNING,MULTICAST,IPv4,VIRTUAL> mtu 8232 index 1
inet 127.0.0.1 netmask ff000000
elxl0: flags=1000843<UP,BROADCAST,RUNNING,MULTICAST,IPv4> mtu 1500 index 2
inet 192.168.1.90 netmask ffffff00 broadcast 192.168.1.255
$ netstat -rn
Routing Table: IPv4
Destination Gateway Flags Ref Use Interface
-------------------- -------------------- ----- ----- ------ ---------
192.168.1.0 192.168.1.90 U 1 3 elxl0
224.0.0.0 127.0.0.1 U 1 0 lo0
default 192.168.1.1 UG 1 0
127.0.0.1 127.0.0.1 UH 8 129 lo0
2. For DNS, the unix PC is configured as a resolver, and the /etc/resolv.conf file is:
$ cat resolv.conf
nameserver 192.168.1.1
nameserver 209.18.47.61
nameserver 209.18.47.62
192.168.1.1 is the Linksys router. The next two are ISP's DNS servers. Since I do not have my own domain, and do not query any hosts of a particular domain, so I do not put a domain/search statement in it.
Now try nslookup:
$ nslookup www.ibm.com
Server: 192.168.1.1
Address: 192.168.1.1#53
Non-authoritative answer:
www.ibm.com canonical name = www.ibm.com.cs186.net.
Name: www.ibm.com.cs186.net
Address: 129.42.58.216
$
3. Now use the ping command:
When ping the unix box from a Windows PC (the PC is also behind the same router), it works OK:
C:\>ping 192.168.1.90
Pinging 192.168.1.90 with 32 bytes of data:
Reply from 192.168.1.90: bytes=32 time=4ms TTL=255
Reply from 192.168.1.90: bytes=32 time=18ms TTL=255
Reply from 192.168.1.90: bytes=32 time=1ms TTL=255
Reply from 192.168.1.90: bytes=32 time=1ms TTL=255
Ping statistics for 192.168.1.90:
Packets: Sent = 4, Received = 4, Lost = 0 (0% loss),
Approximate round trip times in milli-seconds:
Minimum = 1ms, Maximum = 18ms, Average = 6ms
C:\>
However, the other way round, when ping the Windows PC from the unix box, all packets are lost:
$ ping -s 192.168.1.104
PING 192.168.1.104: 56 data bytes
^C
----192.168.1.104 PING Statistics----
5 packets transmitted, 0 packets received, 100% packet loss
Notice that after issuing the ping -s command, it returns one line and the cursor gets stuck on the next line. A Ctrl-C has to be issued to break the deadlock, and the next two lines say that all the packets have been lost.
ping without -s, you still need to use ctrl-C, but simply do not see anything:
$ ping 192.168.1.104
^C$
4. Also on the unix PC, when open the browser, an error pops up as the browser tries to load the default home page www.sun.com, saying that www.sun.com can not be found. I tried chaning the URL to www.ibm.com, the browser gets stuck with the message at bottom status bar: "Resolving host www.ibm.com...". It can not resolve and does not give up either, and the browser refuses to close.
I figure this has something to do with the tcp/ip configuration on the unix PC, especially with DNS configuration, behind a router using NAT where I do not have a DNS domain. This never happened to me where I installed unix in a network environment with our own domain and DNS server. Can someone figure out what could be wrong and how to fix this?
Thanks for helping!
Newman