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binarykungfu
13th July 2005, 12:33 AM
Im having a latency issue with fc3. I added "alias net-pf-10 off" to my modprobe. Here is my resolv.conf. If there is anything eles I can provide to help resolve this issue let me know. thanks

nameserver 166.102.165.11
nameserver 166.102.165.13
search localdomain

binarykungfu
13th July 2005, 01:03 AM
Bump......

kg4cbk
13th July 2005, 02:50 AM
How are you detecting a latency issue?

Try pinging yahoo.com and provide a sample. That will give you a millisecond time for the packets being sent over the network. High latency is usually something well over 300ms. You will see 300+ms response times on a regular bases for systems located overseas or on congested links.

If this is not the problem then more data will be needed to figure out the actual problem.

binarykungfu
13th July 2005, 03:45 AM
like if I open firefox it takes about 30sec before it like starts loading the site. but once its started to download the site it flys. then on the next request the problem happens again. It doesnt matter what day, time, week or website. and its not just in firefox.

kg4cbk
13th July 2005, 04:16 AM
Thats not a latencyissue. :)

That is a performance issue. I have seen a number of people reporting similar types of problems. I have not seen a definitive answer as to the reason.

You should try disabling IPv6. It may be timing out trying to query DNS via IPv6.

The other possibility is that one of the nameservers in /etc/resolv.conf is not responding. If you have multiple nameservers listed and the first one does not respond the system will query the next one in line. That is why you have multiple nameservers listed, in case one goes down.

The reason I think it is a name resoution problem is that after it connects to the site the transfer happens at expected speeds.

You can try to confirm this by running strace on dig or nslookup or even ping and watch for where the delay occurs. Most likely it will happen in the gethostbyname call that will be used to resolve the name to the IP address.

binarykungfu
13th July 2005, 04:36 AM
I swapped my dns addressed around to see if that fixes the problem. I'll keep everyone posted.

kg4cbk
13th July 2005, 04:55 AM
Did you already disable IPv6?

binarykungfu
13th July 2005, 05:01 AM
netstat -rn
Kernel IP routing table
Destination Gateway Genmask Flags MSS Window irtt Iface
192.168.254.0 0.0.0.0 255.255.255.0 U 0 0 0 eth0
169.254.0.0 0.0.0.0 255.255.0.0 U 0 0 0 eth0
0.0.0.0 192.168.254.254 0.0.0.0 UG 0 0 0 eth0

resolv.conf
nameserver 166.102.165.13
nameserver 166.102.165.11
search localdomain

I also added alias net-pf-10 off to modprobe

kg4cbk
13th July 2005, 05:04 AM
And you rebooted or restarted network services?

You might also try:

setenforce 0

This will temporarly disable selinux. I doubt that that is the problem though.

Did you try running strace as suggested?

binarykungfu
13th July 2005, 05:09 AM
set enforce 0 had no effect. I just installed strace and have no idea how to use it. could u provide an example. thanks

binarykungfu
13th July 2005, 05:22 AM
[root@localhost ~]# strace -c firefox
% time seconds usecs/call calls errors syscall
------ ----------- ----------- --------- --------- ----------------
96.44 0.225074 14067 16 8 waitpid
1.42 0.003316 92 36 read
0.54 0.001259 4 283 rt_sigprocmask
0.51 0.001187 148 8 clone
0.22 0.000509 11 46 22 open
0.12 0.000289 7 42 rt_sigaction
0.12 0.000276 276 1 execve
0.11 0.000257 7 38 close
0.07 0.000174 8 23 16 stat64
0.07 0.000161 8 20 old_mmap
0.04 0.000102 5 20 fstat64
0.04 0.000097 14 7 6 access
0.03 0.000078 13 6 munmap
0.03 0.000074 11 7 pipe
0.03 0.000067 8 8 mmap2
0.03 0.000066 8 8 mprotect
0.03 0.000062 4 14 _llseek
0.03 0.000060 4 14 fcntl64
0.02 0.000058 15 4 getdents64
0.02 0.000037 5 8 sigreturn
0.01 0.000035 6 6 brk
0.01 0.000022 6 4 uname
0.01 0.000020 10 2 getpgrp
0.01 0.000017 4 4 dup2
0.01 0.000014 7 2 time
0.00 0.000011 6 2 2 ioctl
0.00 0.000010 5 2 geteuid32
0.00 0.000009 5 2 set_thread_area
0.00 0.000006 3 2 getppid
0.00 0.000006 3 2 getrlimit
0.00 0.000006 3 2 getuid32
0.00 0.000005 3 2 getpid
0.00 0.000005 3 2 getegid32
0.00 0.000004 2 2 getgid32
------ ----------- ----------- --------- --------- ----------------
100.00 0.233373 645 54 total

kg4cbk
13th July 2005, 05:24 AM
Sure. :)

strace ping yahoo.com

You will gets lots and lots of data dumped to the screen. What you are looking for is where the delay is or any error messages that may be displayed.

It may help to redirect the output of strace to a file so you can review it in an editor.

strace ping yahoo.com > tracefile

binarykungfu
13th July 2005, 05:30 AM
Im unable to post the output of strace ping yahoo.com.

binarykungfu
13th July 2005, 05:41 AM
uname({sys="Linux", node="localhost.localdomain", ...}) = 0
brk(0) = 0x8c54000
access("/etc/ld.so.preload", R_OK) = -1 ENOENT (No such file or directory)
open("/etc/ld.so.cache", O_RDONLY) = 4

set_thread_area({entry_number:-1 -> 6, base_addr:0xb7f9c6c0, limit:1048575, seg_
32bit:1, contents:0, read_exec_only:0, limit_in_pages:1, seg_not_present:0, usea
ble:1}) = 0
munmap(0xb7f9e000, 59688) = 0
socket(PF_INET, SOCK_RAW, IPPROTO_ICMP) = -1 EPERM (Operation not permitted)

poll([{fd=4, events=POLLOUT, revents=POLLOUT}], 1, 0) = 1
send(4, "\\Q\1\0\0\1\0\0\0\0\0\0\6yahool\3com\0\0\1\0\1", 28, 0) = 28
poll([{fd=4, events=POLLIN, revents=POLLIN}], 1, 5000) = 1

map2(NULL, 4096, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0xb7 fac000
_llseek(4, 0, 0xbff9a520, SEEK_CUR) = -1 ESPIPE (Illegal seek)
write(4, "ping: icmp open socket: Operatio"..., 48ping: icmp open socket: Operat ion not permitted
) = 48
close(4) = 0
munmap(0xb7fac000, 4096) = 0
exit_group(2) = ?

steve941
13th July 2005, 06:14 AM
If you find an answer, post it. I also have a performance issue.

Seve
13th July 2005, 04:14 PM
Hi:

I agree with kg4cbk as it would seem that this is most likely a DNS or performance issue and not a latency one. In other words, resolving DNS is taking longer than it should.

If you have not already, I would suggest havingt a look at this post which details out some modifications that will improve your DNS performance.
http://www.fedoraforum.org/forum/showthread.php?t=42943


Also, check out some of the tips here if you are using FF http://www.mozilla.org/support/firefox/tips#other

HTH

Seve

binarykungfu
13th July 2005, 08:14 PM
Thanks seve problem fixed