I want to know how to improve the performance of rlogin.
Component:
RS/6000 A: AIX V3.2.5 (4.8.3 BIND)
hostname : hostA.sub1.ac.jp IP:160.24.100.1
primary sub1.ac.jp
secondary sub2.sub1.ac.jp
RS/6000 B: AIX V3.2.4 (4.8.1 BIND)
hostname : hostB.sub2.sub1.ac.jp IP:160.24.50.1
primary sub2.sub1.ac.jp
secondary sub1.ac.jp
RS/6000 C: AIX V3.2.4 (4.8.1 BIND)
hostname : hostC.sub1.ac.jp IP:160.24.100.2
nameserver -> hostA
When RLOGIN from B to A /from B to C, it takes more than 70 seconds.
Another case (from A to B etc.) is no problem, and using
telnet case is OK.
I see RTA000000950 "rlogin performs much worse than telnet", and
check all case of the name resolution. It's no problem.
(I use $HOME/.rhosts and resolution a client IP address is good
response).
What's the cause and how can I improve this?
I took an IP trace and found out the following:
hostB.s2.s1.ac.jp hostC.s1.ac.jp hostA.s1.ac.jp
(160.24.50.1) (160.24.100.2) (160.24.100.1)
push/ack (rsh) -->
--> 160.24.50.1 ?
<-- hostB.s2.s1.ac.jp
* --> hostB.s2.s1.ac.jp.s1.ac.jp ?
<-- s1.ac.jp:hostA.s1.ac.jp
--> hostB.s2.s1.ac.jp.ac.jp ?
***** retry 4 time and wait 75sec time out *****
push/ack <--
ack -->
push/ack <-- (answer of rsh command)
When I change root domain from . to sub1.ac.jp, I avoid this
time out. But still asking wrong name (double domain name).
nslookup command is OK, but host command is bad responce.
Q1: Why is hostC asking wrong hostname only with rsh,rlogin,host
commands ? (nslookup is OK, and I check and check named profiles)
Q2: It seems rshd/rlogind trouble ?
Q3: Are there any possible cause of this trouble?
ANSWER
The problem with rlogin hanging for 70 seconds before coming
back can be caused by "hostB's" inability to resolve hostname
to IP addresses.
Please verify that you are able to resolve hostname to IP
addresses in using the command "host hostB". If this command
takes long time to complete then either your nameserver is
down or it does not have an entry for "hostB". If name
resolution is working fine, make sure that you have configured
the correct hostname and fully qualified domain name (from the
"host hostB" output) in the $HOME/.rhosts and /etc/hosts.equiv
files.
You can also try using IP addresses to "rlogin" instead of
hostnames. If comes back quickly then you will need to check
name resolution on "hostB".
The reason for the double domain name is because your name server
is appending the domain name to a host that is not identified as
having the domain name already in place. Please use the root domain,
a "." (dot, for the root domain), in the nameserver's address record
for hosts that include the full domain name, such as "hostB". For
example:
If hostname entry in the nameserver for domain, "s1.ac.jp",
is as follows:
hostB.s2.s1.ac.jp IN A 160.24.50.1
your nameserver will append the domain name to the hostname
"hostB.s2.s1.ac.jp" if the "dot" is not included. This will
return the following :
hostB.s2.s1.ac.jp.s1.ac.jp
Question1:
The nslookup, rsh, rlogin, and host commands all query your
nameserver for hostname to IP address resolution, however,
nslookup does NOT use BIND routines to do name resolution.
Nslookup uses its own queries to resolve host name to IP addresses.
Question2:
No, rshd/rlogind are working fine at the current levels of AIX
(AIX V3.2.5 and AIX V4.1). Please verify that you are using
the hostname and fully qualified domain name in your /etc/hosts.equiv
and $HOME/.rhosts files.
Question3:
YES, your nameserver configuration needs to be re-visited. I
recommend getting a copy of "DNS and BIND" by O'Reilly &
Associates, Inc. ISBN 1-56592-010-4. This book is a comprehensive
book on nameserver configuration.
S e a r c h - k e y w o r d s:
DNS
WWQA: ITEM: RTA000087821 ITEM: RTA000087821
Dated: 01/1997 Category: ITSAI6000CO
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