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linux（7）
&ping: unknown host &&
解决方案：&
&&&如果某台Linux服务器ping不通域名, 如下提示:&
[root@localhost ~]# ping
ping: unknown host
首先确定已经连接上路由器，并且路由器能够访问外网，可以通过访问网关进行确定
[root@localhost ~]# ping 192.168.1.1
PING 192.168.1.1 (192.168.1.1) 56(84) bytes of data.
64 bytes from 192.168.1.1: icmp_seq=1 ttl=64 time=2.96 ms
64 bytes from 192.168.1.1: icmp_seq=2 ttl=64 time=1.75 ms
如果确定网络没问题的情况下, 可以通过如下步骤寻找解决办法:&
1) 确定设置了域名服务器, 没有的话, 建议设置Google的公共DNS服务, 它应该不会出问题的&
[root@localhost ~]# cat /etc/resolv.conf
search localdomain
因为我的DNS没有设置所以导致了ping外网ping不通。将dns添加到该文件中
[root@localhost ~]# vi /etc/resolv.conf
search localdomain
nameserver 202.98.96.68
nameserver 61.139.2.69
2) 确保网关已设置&
# grep GATEWAY /etc/sysconfig/network-scripts/ifcfg*&
-------------------------------------------------------------------&
/etc/sysconfig/network-scripts/ifcfg-eth0:GATEWAY=192.168.40.1&
-------------------------------------------------------------------&
如果未设置, 则通过如下方式增加网关:&
# route add default gw 192.168.40.1&
或者手工编写/etc/sysconfig/network-scripts/ifcfg*文件后, 重启network服务:&
# service network restart&
3) 确保可用dns解析&
# grep hosts /etc/nsswitch.conf&
-------------------------------------------------------------------&
hosts:&&&&& files dns&
-------------------------------------------------------------------&
如果以上哪个有问题, 修正后, 再测试, 应该就没问题了:&
#ping -c 3 &
PING www. (220.181.6.175) 56(84) bytes of data.&
64 bytes from 220.181.6.175: icmp_seq=0 ttl=50 time=9.51 ms&
64 bytes from 220.181.6.175: icmp_seq=1 ttl=50 time=8.45 ms&
64 bytes from 220.181.6.175: icmp_seq=2 ttl=50 time=8.97 ms&
--- www. ping statistics ---&
3 packets transmitted, 3 received, 0% packet loss, time 2002ms&
rtt min/avg/max/mdev = 8.450/8.977/9.511/0.446 ms, pipe 2&
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Jan 15, 2010
I am installing ISPconfig on a Ubuntu server 9.10. When i write
hostname -f i get the unknown host message.
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May 25, 2010
I just built out an Ubuntu Server 10.04.My problem is setting the hostname. I cloned the machine, then normally on the clone, I would change the /etc/hostname and /etc/hosts file.However, when I do this, upon restart, I get the message, &init hostname main process (some process number) terminated with status 1&Then, when the machine finally boots, the hostname is set to (none). Literally has braces like: user@(none):I've tried: sudo hostname machine_name but it says can't resolve hostname (none).I've Google'd around a lot but can't get it. It may have something to do with 10.04? I have been using 9.04, 9.10 with no problems.eric@(none):~$ cat /etc/network/interfaces # This file describes the network interfaces available on your system# and how to activate them. For more information, see interfaces(5).# The loopback network interfaceauto loiface lo inet loopback# The primary network interfacecode....
May 13, 2011
Even ping google's ip address doesn't work. unknown host error using backtrack4 able to browse net with these settings.My network settings:What's the problem with these settings...
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I have a network of 2 WinXP machines and one linux box. I have fiddled around with the settings as you do when learning. The network is working. The network neighbourhood on the WinXP machines recognise the linux box and vice versa, (the linux Places|Network recognises the 2 WinXP). I can Ping the linux box using its hostname from a WinXp. But I cannot do the reverse. I get an 'unknown host' response. I can ping the linux to itself using its hostname.
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I am using comcast ISP with DHCP.When I type in hostname -f it says unknown hostin /etc/sysconfig/networkhostname=in /etc/hosts127.0.0.1
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Aug 10, 2010
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Nov 24, 2010
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May 24, 2010
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Apr 12, 2010
I have some problem some one changed hostname on my system. If I do following I seeCode:knoppix:~# cat /etc/hostname debianknoppix which is coming in left side in above output is not my hostname.The hostname is debian.How do I get that name back so that when I do
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Copyrights 2005-15 , All rights reservedSearch similar:
uniqs30729
Unknown Host (server does not have a DNS entry) ?Description: Unable to locate the server named "www.************.com" --- the server does not have a DNS entry. Perhaps there is a misspelling in the server name, or the server no longer exists. Double-check the name and try again. ****what does this mean. Other then the obvious, because this has also come up a few times when i go to sites i've previously been to (they do exist)
& <font color=#2-Mar-14 1:28 am &
It could mean a number of things:1.
They didn't pay their bill.2.
The DNS server that your using didn't update properly.3.
It was a hack site squatting on that DNS Entry.That's about I can think of at the moment.
& <font color=#2-Mar-14 2:44 am &
to This is telling you that your domain-name-server (DNS) cannot find a numerical xxx.xxx.xxx.xxx internet address corresponding to the alpha-numeric host name
that you entered.
It could be that the site doesn't exist, or that you cannot contact your DNS.
Usually you have a backup or secondary DNS to contact too.
Your DNS addresses may be statically or dynamically assigned, depending on your internet service provider (ISP).
& <font color=#2-Mar-14 2:49 am &
Your DNS addresses may be statically or dynamically assigned, depending on your internet service provider (ISP).so can i manually change my DNS address (sorry if i sound stupid, but i don't know how this works)? and if so how.****btw, just an examplefrom &the very first screenshot (in the left) when i click on it, i get********Unknown HostDescription: Unable to locate the server named "www." --- the server does not have a DNS entry.
Perhaps there is a misspelling in the server name, or the server no longer exists.
Double-check the name and try again.
& <font color=#2-Mar-14 3:29 am &
to What type of connection to the internet do you have (cable, DSL, dialup, etc.)?
& <font color=#2-Mar-14 3:40 am &
i got cable (optus in Australia)
& <font color=#2-Mar-14 6:49 am &
to ogadaba....not that you do not have a problem BUT for the example you gave there IS an answer....When I did a Google search for the word taxster....the first selection was.... >>>> Now moved to Taxster.cjb.net. If I then clicked on....Taxster.cjb.net....I was then redirected to &If you have other possible DNS issues....feel free to post other examples. Maybe there is a valid reason for those also.
& <font color=#2-Mar-14 6:52 am &
to Hi... I have the same exact problem... 1% of the sites I try I get this error. If I try over and over I can get through. What's weird is that it only affects one PC... not the others in the house.PacBell DSL - No. Calif, just installed.One of the sites I cannot get to is this one -Another one: &Please help...
& <font color=#2-Mar-21 3:41 am &
to said by ogadaba:Description: Unable to locate the server named "www.************.com" --- the server does not have a DNS entry. Perhaps there is a misspelling in the server name, or the server no longer exists. Double-check the name and try again. what does this mean. Other then the obvious, because this has also come up a few times when i go to sites i've previously been to (they do exist) I've seen this sort of result for valid domains several times in recent days.My first impression is that there is something going on with the root DNS servers.
When locally cached records expire, your ISP's DNS server goes to the root servers for pointers to the authoritative servers, where in turn it retrieves fresh DNS information.In one of the cases where I could not reach a known valid domain, the root servers appeared to be responding that there was no authoritative source, even though a direct check confirmed that the authoritative server existed and was online.I'm seeing some other reports of similar problems.
So far they seem to be short-lived.To be quite honest, I am a bit concerned.
This is the sort of failure that could cause serious Net-wide problems.Any number of innocent things might explain this sort of failure.
Excessive loads, server update gliteches at the root level, etc.
But some not-so innocent possibi attacks on the root servers, expolits of various/possible sorts, perhaps attacks or breakdowns at major backbone nodes.
Whatever it is, I sure hope someone has a handle on it.pchelp
& <font color=#2-Mar-21 1:21 pm &
to I am not having *any* problems accessing sites from my work... the same sites I cannot get to from home... if the problem is outside my PC... it's with the PacBell DNS servers (MHO).
& <font color=#2-Mar-21 2:09 pm &
said by dddonly:I am not having *any* problems accessing sites from my work... the same sites I cannot get to from home... if the problem is outside my PC... it's with the PacBell DNS servers (MHO). Based on what I observed, the problem can't be evaluated quite that way.DNS records have a configurable "time-to-live" parameter that is transmitted with the name/IP information.
If your DNS server's cached record just happens to have expired, it will seek out a fresh one.
Servers whose records are unexpired will hand out the information without having to seek it out again.So while the appearance may be that server A is working while B in fact _whatever_ one of them happens to have an expired record would produce an error if either the root servers or the authoritative source to which they point, should fail to respond or produce flawed data.pchelp
& <font color=#2-Mar-21 2:56 pm &
&Nimda seems to be runing around all over the place again.I think if you look at the Certs...the problem is back.
& <font color=#2-Mar-21 3:43 pm &
to said by ogadaba:btw, just an examplefrom &the very first screenshot (in the left) when i click on it, i get********Unknown HostWhat browser are you using? When i click on those links with IE6 i get the very common "page cannot be displayed" "Cannot find server or DNS ErrorInternet Explorer". Probabaly just bad/broken links.
& <font color=#2-Mar-21 6:53 pm &
to PChelp... thanks, that makes sense... but then why would one of my PCs consistently fail, while the other -- sitting right next to it, talking to the same router/modem -- fail?I've done back to back tests... PC1 never fails... PC2 fails 99% of the time (while accessing a few specific sites).BTW, the machine that fails is Win2000... I ran nslookup and keep getting back "DNS request timed out."
& <font color=#2-Mar-21 6:58 pm &
to &ogadaba, what ever happened back here in this thread? Have you been having this problem since then and is it the same machine?
& <font color=#2-Mar-21 7:38 pm &
to Managed to solve my problem... thanks all.&
& <font color=#2-Mar-22 2:56 am &