Hello World,
First of all, I would like to thank everyone who has replied and provided
valuable information, including:
tom@math.uni-paderborn.de (Torsten Metzner)
mike@trdlnk.com (Michael T. Sullivan)
aub@ide.com (Alberto) --Nice to meet you over the internet, my old colleague.
qwe@ht.eimb.rssi.ru (Fedor Gnuchev)
zzlevo@dd.chalmers.se (Andreas Gunnarsson)
jigang@bit.csc.lsu.edu (Jigang Liu)
My question posted 2 days ago:
__________________________________________________________
> I am installing Solaris2.5 on an UltraSparc 170e and Solaris2.4 on a
> SS20. I ran into a weird problem with both machine. I could not see
> most of our other systems within the LAN.
> What I did during the installation:
> I set the IP of my system as 163.184.22.74 and netmask as 255.255.255.196.
> Than when I boot the system after finished the installation, I could only see.
> myself. I checked the /etc/netmasks file and see one line theres
> 163.184.0.0 255.255.255.196 . Then I change it to yan22
> 163.184.22.0 255.255.255.196 and reboot my system. I can see a few of
> our systems here. Below is the result of "rup":
> chjs27 up 3 mins, load average: 0.20, 0.10, 0.04
> 163.184.22.1 up 3:46, load average: 0.36, 0.23, 0.20
> 163.184.22.3 up 2 days, 2:19, load average: 0.93, 0.88, 0.60
> 163.184.22.5 up 2 days, 4:22, load average: 0.43, 0.38, 0.01
> 163.184.22.1 up 2 days, 4:24, load average: 0.00, 0.00, 0.00
> 163.184.22.2 up 2 days, 4:21, load average: 3.00, 3.00, 3.00
> 163.184.22.1 up 2 days, 4:25, load average: 0.25, 0.27, 0.20
>
> chjs27 is the hostname of my machine. Whthinchis
27
> Within the list I could only access 163.184.22.3 and 163.184.22.2.
> 163.184.22.1 does not exist at all but I have it defined in a hosts file.
> 163.184.22.5 exists but I can not even ping to it.
> This really drives me crazy. Help pls!
-------------------------------------------------------------
As you all pointed out, my netmask was wrong. It should be 255.255.255.192
instead of 255.255.255.196. I changed the entry in /etc/netmasks to
163.184.0.0 255.255.255.192
And also I changed the IP address of my host to 163.184.22.56. It works.
Special thanks to Torsten and Michael who gave me the most detailed answers.
Below are the quoted replies from them.
Begining of Torsten's message:
*********
|Dear Sun masters,
| I am installing Solaris2.5 on an UltraSparc 170e and Solaris2.4 on a
|SS20. I ran into a weird problem with both machine. I could not see
|most of our other systems within the LAN.
| What I did during the installation:
| I set the IP of my system as 163.184.22.74 and netmask as 255.255.255.196.
|Than when I boot the system after finished the installation, I could only see.
|myself. I checked the /etc/netmasks file and see one line theres
| 163.184.0.0 255.255.255.196 . Then I change it to yan22
| 163.184.22.0 255.255.255.196
Arrggg, that was wrong.
The right entry is:
163.184.0.0 255.255.255.196
Because 163.184.22.74 is a class B address. So your class B network number
is 163.184.0.0. and in the /etc/netmasks file you set the netmask for the
real class B address, NOT for the subnet !!
BTW 255.255.255.196 is a funny netmask for a class B address.
255.255.255.196 = 11111111 11111111 11111111 11000100
Bit31 Bit 0
That's not wrong ( RFC950 ) but are you sure what's the meaning of this mask ?
(a) Bit 2 and bits 6-31 specify the network and bits 0-1 and bits 3-5
specify the host.
E.g. host 163.184.22.195 and host 163.184.22.197 are on different nets !!
Because host 163.184.22.195 is host number 3 on net 163.184.22.192
and host 163.184.22.197 is host number 1 on net 163.184.22.196
(b) You have 11 bits for the subnets and 5 bits for the hosts.
So you can have only 2^5 - 2 = 30 hosts on every subnet but you can
have 2^11 = 2048 subnets.
| Within the list I could only access 163.184.22.3 and 163.184.22.2.
| 163.184.22.1 does not exist at all but I have it defined in a hosts file.
| 163.184.22.5 exists but I can not even ping to it.
163.184.22.5 is host number 1 on net 163.184.22.4
163.184.22.3 is host number 3 on net 163.184.22.0 {;-))
| This really drives me crazy. Help pls!
Ok here are some things to check.
(1) Have every host on your LAN the same subnetmask ?!!
That's really important. Try ifconfig to check it.
(2) Have a look at your routers and at the routing table entries.
On a SUN you can use the netstat -rn command.
(3) If you have a /etc/defaultrouter file, then you must be sure that the
entry is correct.
Hope this helps,
Torsten.
***************** End of Torsten's message
########Begining of Michael's message
You should first check if 255.255.255.196 is really the proper netmask.
I note that it violates the recommendation in RFC-950 that the
"ones" in the subnet mask be contiguous.
Given that netmask, or even one in which the ones are contiguous such as
255.255.255.192, your machine chjs27 will be on a separate subnet from
any of the other machines whose IP addresses you mentioned, and the
it should not be able to communicate with them unless extra steps are taken
(such as special routing table entries, or some other machine on the net
acting as a router between the two subnets). If you expect your machine
to be able to talk directly to those other machines on the same LAN
without such extraordinary measures, then you must use a different netmask.
I can't say what it should be without knowing your network architecture.
Secondly, you should have not have changed the netmasks entry.
The original entry,
163.184.0.0 255.255.255.196
was correct (aside from any possible problems with the netmask value).
What you changed it to:
163.184.22.0 255.255.255.196
is incorrect because the network number in the first column must not
reflect any subnetting (subnetting applies to an entire network, not
individual subnets).
For more information about subnetting, read RFC-950, RFC-1219, and RFC-1860.
-- ################## End of Michael's messageIt's just so nice to be in the list, but unfortunately I don't have time to read all the useful messages. I may be back someday.
Thanks again and with best regards to you all.
Geping
This archive was generated by hypermail 2.1.2 : Fri Sep 28 2001 - 23:10:56 CDT