Results 1 to 2 of 2
Hi folks,
My FC3 workstation is connected 1o 1.5Mb broadband via ADSL modem to telephone line and with dynamic IP allotted on connection.
I have been suffering on slow Internet ...
Enjoy an ad free experience by logging in. Not a member yet? Register.
- 02-12-2006 #1Linux Guru
- Join Date
- Sep 2004
- Posts
- 1,712
Networking question
Hi folks,
My FC3 workstation is connected 1o 1.5Mb broadband via ADSL modem to telephone line and with dynamic IP allotted on connection.
I have been suffering on slow Internet browsing for a week on acount of dead primary nameserver which was found later. Each time after connecting ISP server a set of nameservers was allotted, namely the primary and secondary nameservers. They were seldomly changed, almost the same set each time on connection. The ISP disputed my finding saying the primary nameserver was alive pinged on his Windows PC. Finally the ISP changed another new set of nameservers. But the new primary nameserver assigned still died.
New set of nameservers;
# cat /etc/resolv.conf
nameserver 203.123.77.196 (Primary)
nameserver 202.123.77.213 (Secondary)
The history of ping and traceroute are as follows;
ping command
============
1)
Tested on FC3
# ping -c 3 202.123.77.196It indicated 100% packet loss.Code:PING 202.123.77.196 (202.123.77.196) 56(84) bytes of data. From 202.123.95.82 icmp_seq=0 Time to live exceeded From 202.123.95.82 icmp_seq=1 Time to live exceeded From 202.123.95.82 icmp_seq=2 Time to live exceeded --- 202.123.77.196 ping statistics --- 3 packets transmitted, 0 received, +3 errors, 100% packet loss, time 2002ms, pipe 2
2)
Tested on WinME
C:\WINDOWS>ping -n 3 202.123.77.196From the abve it indicates 0% packet loss. Now I'm not surprised why the ISP claimed no problem on the nameservers pinged on his Windows PC. Windows allowed the feedback from another nameserver getting through and indicating 0% packet loss. I suppose this was the security problem. If I'm wrong please correct me. Tks.Code:Pinging 202.123.77.196 with 32 bytes of data: Reply from 202.123.95.82: TTL expired in transit. Reply from 202.123.95.82: TTL expired in transit. Reply from 202.123.95.82: TTL expired in transit. Ping statistics for 202.123.77.196: Packets: Sent = 3, Received = 3, Lost = 0 (0% l Approximate round trip times in milli-seconds:
3)
Tested on FC3
# ping -c 3 202.123.77.213No packet loss found.Code:PING 202.123.77.213 (202.123.77.213) 56(84) bytes of data. 64 bytes from 202.123.77.213: icmp_seq=0 ttl=252 time=37.3 ms 64 bytes from 202.123.77.213: icmp_seq=1 ttl=252 time=18.7 ms 64 bytes from 202.123.77.213: icmp_seq=2 ttl=252 time=18.9 ms --- 202.123.77.213 ping statistics --- 3 packets transmitted, 3 received, 0% packet loss, time 2002ms rtt min/avg/max/mdev = 18.729/25.001/37.335/8.723 ms, pipe 2
traceroute
==========
1)
Tested on FC3
# traceroute 202.123.77.196found jumping between routers. If my suppose is WRONG, please correct me.Code:traceroute to 202.123.77.196 (202.123.77.196), 30 hops max, 38 byte packets 1 203.88.164.1 (203.88.164.1) 34.436 ms 18.725 ms 17.194 ms 2 202-123-94-73.ihenderson.com (202.123.94.73) 31.701 ms 17.349 ms 17.180 ms 3 202-123-94-51.ihenderson.com (202.123.94.51) 33.842 ms 16.773 ms 17.193 ms 4 202-123-95-82.ihenderson.com (202.123.95.82) 29.837 ms 17.027 ms 17.181 ms 5 hdc-coreB-fe110.ihenderson.com (202.123.95.81) 33.179 ms 16.775 ms 17.461 ms 6 202-123-95-82.ihenderson.com (202.123.95.82) 28.888 ms 23.199 ms 17.346 ms 7 hdc-coreB-fe110.ihenderson.com (202.123.95.81) 32.042 ms 18.007 ms 17.933 ms 8 202-123-95-82.ihenderson.com (202.123.95.82) 34.393 ms 18.015 ms 16.936 ms 9 hdc-coreB-fe110.ihenderson.com (202.123.95.81) 25.559 ms 17.237 ms 17.462 ms 10 202-123-95-82.ihenderson.com (202.123.95.82) 37.132 ms 18.018 ms 17.452 ms 11 hdc-coreB-fe110.ihenderson.com (202.123.95.81) 38.051 ms 17.523 ms 17.176 ms 12 202-123-95-82.ihenderson.com (202.123.95.82) 36.670 ms 17.502 ms 17.194 ms 13 hdc-coreB-fe110.ihenderson.com (202.123.95.81) 35.245 ms 17.743 ms 17.465 ms 14 202-123-95-82.ihenderson.com (202.123.95.82) 33.834 ms 17.497 ms 17.192 ms 15 hdc-coreB-fe110.ihenderson.com (202.123.95.81) 31.714 ms 17.290 ms 17.175 ms 16 202-123-95-82.ihenderson.com (202.123.95.82) 29.592 ms 17.966 ms 17.934 ms 17 hdc-coreB-fe110.ihenderson.com (202.123.95.81) 36.741 ms 19.286 ms 17.399 ms 18 202-123-95-82.ihenderson.com (202.123.95.82) 33.879 ms 17.482 ms 17.181 ms 19 hdc-coreB-fe110.ihenderson.com (202.123.95.81) 30.061 ms 17.550 ms 17.451 ms 20 202-123-95-82.ihenderson.com (202.123.95.82) 33.983 ms 17.933 ms 17.698 ms 21 hdc-coreB-fe110.ihenderson.com (202.123.95.81) 27.707 ms 17.477 ms 16.965 ms 22 202-123-95-82.ihenderson.com (202.123.95.82) 32.793 ms 17.480 ms 17.446 ms 23 hdc-coreB-fe110.ihenderson.com (202.123.95.81) 36.703 ms 17.719 ms 17.952 ms 24 202-123-95-82.ihenderson.com (202.123.95.82) 30.638 ms 17.701 ms 18.198 ms 25 hdc-coreB-fe110.ihenderson.com (202.123.95.81) 34.904 ms 18.215 ms 18.188 ms 26 202-123-95-82.ihenderson.com (202.123.95.82) 29.862 ms 17.978 ms 16.940 ms 27 hdc-coreB-fe110.ihenderson.com (202.123.95.81) 23.821 ms 17.564 ms 18.855 ms 28 202-123-95-82.ihenderson.com (202.123.95.82) 36.947 ms 17.711 ms 17.946 ms 29 hdc-coreB-fe110.ihenderson.com (202.123.95.81) 30.599 ms 17.972 ms 18.178 ms 30 202-123-95-82.ihenderson.com (202.123.95.82) 34.263 ms 17.716 ms 17.940 ms
2)
Tested on server on Internet, run by "traceroute.org"It indicates gateway errorCode:Version: v1.0 Date: 22-Jan-2002 Tracing route to 202-123-77-196.ihenderson.com [202.123.77.196] over a maximum of 30 hops: 1 <10 ms <10 ms <10 ms 202.85.152.2 2 <10 ms <10 ms <10 ms ge1-2-cosw0907.hk01.iadvantage.net [202.85.129.50] 3 57 ms 235 ms 223 ms henderson-rge.hkix.net [202.40.161.105] 4 2 ms 2 ms 2 ms 202-123-94-91.ihenderson.com [202.123.94.91] 5 2 ms 2 ms 2 ms 202-123-94-51.ihenderson.com [202.123.94.51] 6 2 ms 2 ms 2 ms 202-123-95-82.ihenderson.com [202.123.95.82] 7 2 ms 2 ms 3 ms hdc-coreb-fe110.ihenderson.com [202.123.95.81] 8 2 ms 2 ms 3 ms 202-123-95-82.ihenderson.com [202.123.95.82] 9 2 ms 3 ms 2 ms hdc-coreb-fe110.ihenderson.com [202.123.95.81] 10 2 ms 2 ms 2 ms 202-123-95-82.ihenderson.com [202.123.95.82] 11 3 ms 3 ms 3 ms hdc-coreb-fe110.ihenderson.com [202.123.95.81] 12 2 ms 2 ms 2 ms 202-123-95-82.ihenderson.com [202.123.95.82] 13 2 ms 3 ms 3 ms hdc-coreb-fe110.ihenderson.com [202.123.95.81] 14 3 ms 3 ms 2 ms 202-123-95-82.ihenderson.com [202.123.95.82] 15 3 ms 3 ms 3 ms hdc-coreb-fe110.ihenderson.com [202.123.95.81] 16 3 ms 2 ms 3 ms 202-123-95-82.ihenderson.com [202.123.95.82] 17 2 ms 3 ms 2 ms hdc-coreb-fe110.ihenderson.com [202.123.95.81] 18 2 ms 2 ms 3 ms 202-123-95-82.ihenderson.com [202.123.95.82] 19 3 ms 3 ms 3 ms hdc-coreb-fe110.ihenderson.com [202.123.95.81] 20 3 ms 2 ms 3 ms 202-123-95-82.ihenderson.com [202.123.95.82] 21 3 ms 3 ms 3 ms hdc-coreb-fe110.ihenderson.com [202.123.95.81] 22 3 ms 3 ms 3 ms 202-123-95-82.ihenderson.com [202.123.95.82] 23 4 ms 3 ms 3 ms hdc-coreb-fe110.ihenderson.com [202.123.95.81] 24 3 ms 3 ms 3 ms 202-123-95-82.ihenderson.com [202.123.95.82] 25 3 ms 3 ms 3 ms hdc-coreb-fe110.ihenderson.com [202.123.95.81] 26 3 ms 3 ms 3 ms 202-123-95-82.ihenderson.com [202.123.95.82] 27 4 ms 5 ms 3 ms hdc-coreb-fe110.ihenderson.com [202.123.95.81] 28 4 ms 3 ms 3 ms 202-123-95-82.ihenderson.com [202.123.95.82] 29 3 ms 3 ms 3 ms hdc-coreb-fe110.ihenderson.com [202.123.95.81] 30 3 ms 3 ms 3 ms 202-123-95-82.ihenderson.com [202.123.95.82] Trace complete. HTTP/1.1 502 Gateway Error Server: Microsoft-IIS/5.0 Date: Thu, 09 Feb 2006 05:51:23 GMT Connection: close Content-Length: 186 Content-Type: text/html
3)
Tesed on FC3
# traceroute 202.123.77.213Exited automatically.Code:traceroute to 202.123.77.213 (202.123.77.213), 30 hops max, 38 byte packets 1 203.88.164.1 (203.88.164.1) 27.979 ms 16.987 ms 16.785 ms 2 202-123-94-67.ihenderson.com (202.123.94.67) 27.374 ms 17.286 ms 17.442 ms 3 202-123-95-82.ihenderson.com (202.123.95.82) 27.671 ms 17.258 ms 17.430 ms 4 202-123-77-222.ihenderson.com (202.123.77.222) 28.253 ms 18.010 ms 17.931 ms 5 ns02.ihenderson.com (202.123.77.213) 28.815 ms 18.266 ms 17.677 ms
4)
Tested on server on Internet, run by "traceroute.org"No error indicated.Code:Version: v1.0 Date: 22-Jan-2002 Copyright: Sum.com.hk Tracing route to ns02.ihenderson.com [202.123.77.213] over a maximum of 30 hops: 1 <10 ms 1 ms <10 ms 202.85.152.2 2 <10 ms <10 ms <10 ms ge1-2-cosw0907.hk01.iadvantage.net [202.85.129.50] 3 2 ms 2 ms 2 ms henderson-rge.hkix.net [202.40.161.105] 4 2 ms 2 ms 2 ms 202-123-94-91.ihenderson.com [202.123.94.91] 5 3 ms 2 ms 2 ms 202-123-94-51.ihenderson.com [202.123.94.51] 6 3 ms 2 ms 2 ms 202-123-95-82.ihenderson.com [202.123.95.82] 7 2 ms 4 ms 3 ms 202-123-77-218.ihenderson.com [202.123.77.218] 8 3 ms 2 ms 2 ms ns02.ihenderson.com [202.123.77.213] Trace complete.
Now each time after booting up the PC I have to revert the order of nameservers on /etc/resolv.conf. Since they are seldomly changed. Can I run them as static IP. If YES, please advise which file shall I edit to effect the change, not running them as dynamic IP. Tks.
Furthermore please help me to understand what are the possible causes on ISP server with this mistake generated. TIA
B.R.
satimis
- 02-15-2006 #2Linux User
- Join Date
- Apr 2005
- Location
- Ohio
- Posts
- 326
I would actually use dig to test name servers.. Some ISPs block icmp packets to the DNS servers so Ping and traceroute may not be very good tools for testing.
dig @203.123.77.196 google.com
dig @202.123.77.213 google.com
dig is a dns lookup (domain internet groper)
the @IPADDRESS specifies a specific DNS server to use for the query
google.com is just a domiain name to test with, you can use any you like.
itg-debian:/proc# dig @192.168.0.24 google.com
dig @192.168.0.24 google.com
; <<>> DiG 9.2.4 <<>> @192.168.0.24 google.com
;; global options: printcmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 1710
;; flags: qr aa; QUERY: 1, ANSWER: 3, AUTHORITY: 4, ADDITIONAL: 4
;; QUESTION SECTION:
;google.com. IN A
;; ANSWER SECTION:
google.com. 300 IN A 64.233.187.99
google.com. 300 IN A 64.233.167.99
google.com. 300 IN A 72.14.207.99
;; AUTHORITY SECTION:
google.com. 345600 IN NS ns1.google.com.
google.com. 345600 IN NS ns2.google.com.
google.com. 345600 IN NS ns3.google.com.
google.com. 345600 IN NS ns4.google.com.
;; ADDITIONAL SECTION:
ns1.google.com. 345600 IN A 216.239.32.10
ns2.google.com. 345600 IN A 216.239.34.10
ns3.google.com. 345600 IN A 216.239.36.10
ns4.google.com. 345600 IN A 216.239.38.10
;; Query time: 41 msec
;; SERVER: 192.168.0.24#53(192.168.0.24)
;; WHEN: Wed Feb 15 14:02:24 2006
;; MSG SIZE rcvd: 212
This will do actual name queries against the servers.. just because the do or don't respond to a ping or traceroute doesn't mean they won't respond to actual DNS queries.
Personally I would find this more usefull when testing DNS. epsecially if the server responds saying refused or connection refused, etc...
Error Messages
If lookup was not successful, one of these common error messages may display:
Timed out - The server didn't respond to a request after a certain amount of time and a certain number of retries.
No response from server - No name server is running on the server machine.
No records - The server doesn't have resource records of the current query type for the host, although the hostname is valid.
Nonexistent domain - The hostname or domain name doesn't exist.
Connection refused -- Network is unreachable - The connection to the name or finger server couldn't be made at the current time.
Server failure - The name server found an internal inconsistency in its database and couldn't return a valid answer.
Refused - The name server refused to service the request.
Format error - The name server found that the request packet wasn't in the proper format.
Try dig and see what you get.
/etc/resolv.conf is the file that contains the DNS server addresses.far...out
Reply With Quote 
Posting Permissions
- You may not post new threads
- You may not post replies
- You may not post attachments
- You may not edit your posts
