Network Problem: Destination Host Unreachable

theta · 2010-03-21 06:16:02

I just upgraded my system after a month. After the upgrade the network is not working through the shell. Its working fine through firefox.

I use a http proxy to connect to the net.

I can ping to the local lan ips.

I think the problem is with the hosts file. I am new to this and don't understand their structure. Any help would be appreciated.

Config Files:

[theta@boolean-pc ~]$ cat /etc/resolv.conf
# Generated by dhcpcd from wlan0
# /etc/resolv.conf.head can replace this line
nameserver 172.20.0.253
nameserver 172.20.0.211
# /etc/resolv.conf.tail can replace this line

[theta@boolean-pc ~]$ cat /etc/hosts
#
# /etc/hosts: static lookup table for host names
#

#<ip-address> <hostname.domain.org> <hostname>
127.0.0.1 localhost.localdomain localhost boolean-pc
# End of file

[theta@boolean-pc ~]$ cat /etc/hosts.allow
#
# /etc/hosts.allow
#
ALL:ALL:ALLOW
# End of file
[theta@boolean-pc ~]$ cat /etc/hosts.deny
#
# /etc/hosts.deny
#

#ALL: ALL: DENY

# End of file

I am also facing the same "Transient Resolver Failure" problem with pacman which has been faced by many as per the forums. But still none of the solutions are working for me.

Last edited by theta (2010-03-21 09:23:02)

grey · 2010-03-21 16:29:16

The configuration files look fine to me. What type of local area network are you sitting on? It sounds like you have your machine running arch, and then there are other machines on the local network, including one that serves as the gateway to the net. Is that correct? Also, what type of network services are you trying to get via the shell? I'm assuming as a first step ping www.google.com - right?

theta · 2010-03-24 16:43:29

Yes I am using arch. I use wifi to connect to the local network.
The server of the LAN has a squid proxy installed to access the internet.
The local gateway is the wifi router itself.

I am able to use wget, aria2c to download files via the shell but I was not able to use pacman to do any updates. Neither am I able to ping any website.

[theta@boolean-pc ~]$ ping http://www.google.com
ping: unknown host http://www.google.com

Also nslookup gives the follwowing output:

theta@boolean-pc ~]$ nslookup www.google.com
;; Got SERVFAIL reply from 172.20.0.253, trying next server
;; Got SERVFAIL reply from 172.20.0.253, trying next server
Server:        172.20.0.211
Address:    172.20.0.211#53

** server can't find www.google.com: SERVFAIL

where 172.20.0.253 is the actual DNS Server.

PS: There are restrictions on the proxy server regarding file size limit, etc but still this used to work before one upgrade.
Also I can perform all the above operations when I use GPRS to connect to the Net(when there is no proxy involved)

Nepherte · 2010-03-24 18:39:11

theta wrote:

[theta@boolean-pc ~]$ ping http://www.google.com
ping: unknown host http://www.google.com

This behavior is quite normal. http:// is a protocol and has nothing to do with hostnames whatsover so you can't ping it either. Try

ping google.com

theta · 2010-03-24 20:03:34

I have tried all that, but nothing seems to give the desired result.
As of now my main problem is that I get the following error when trying to update:

[theta@boolean-pc ~]$ sudo pacman -Syy
Password: 
:: Synchronizing package databases...
error: failed retrieving file 'core.db.tar.gz' from mirror.csclub.uwaterloo.ca : Transient resolver failure
error: failed retrieving file 'core.db.tar.gz' from mirrors.portafixe.com : Transient resolver failure
error: failed retrieving file 'core.db.tar.gz' from mirror.archlinux.com.ve : Transient resolver failure
error: failed retrieving file 'core.db.tar.gz' from archlinux.unixheads.org : Transient resolver failure
error: failed to update core (Transient resolver failure)
error: failed retrieving file 'extra.db.tar.gz' from mirror.csclub.uwaterloo.ca : Transient resolver failure
error: failed retrieving file 'extra.db.tar.gz' from mirrors.portafixe.com : Transient resolver failure
error: failed retrieving file 'extra.db.tar.gz' from mirror.archlinux.com.ve : Transient resolver failure
error: failed retrieving file 'extra.db.tar.gz' from archlinux.unixheads.org : Transient resolver failure
error: failed to update extra (Transient resolver failure)
error: failed retrieving file 'community.db.tar.gz' from mirror.csclub.uwaterloo.ca : Transient resolver failure
error: failed retrieving file 'community.db.tar.gz' from mirrors.portafixe.com : Transient resolver failure
error: failed retrieving file 'community.db.tar.gz' from mirror.archlinux.com.ve : Transient resolver failure
error: failed retrieving file 'community.db.tar.gz' from archlinux.unixheads.org : Transient resolver failure
error: failed to update community (Transient resolver failure)
error: failed retrieving file 'archlinuxfr.db.tar.gz' from repo.archlinux.fr : Transient resolver failure
error: failed to update archlinuxfr (Transient resolver failure)
error: failed to synchronize any databases
[theta@boolean-pc ~]$

theta · 2010-03-25 17:46:46

I just found out the following warning during the last update:

(211/258) upgrading pacman-mirrorlist               [#####################] 100%
warning: /etc/pacman.d/mirrorlist installed as /etc/pacman.d/mirrorlist.pacnew

Could this have anything to do witht the errors I'm facing

Last edited by theta (2010-03-26 03:20:32)

theta · 2010-03-26 09:37:07

Found another interesting scenario. If I use wget to download my packages via pacman I get the following error.

[theta@boolean-pc ~]$ sudo pacman -Syy
:: Synchronizing package databases...
--2010-03-26 15:05:45--  http://mirror.csclub.uwaterloo.ca/archlinux/core/os/i686/core.db.tar.gz
Resolving mirror.csclub.uwaterloo.ca... failed: Temporary failure in name resolution.
wget: unable to resolve host address "mirror.csclub.uwaterloo.ca"
error: failed to update core (error invoking external downloader)

And when I try to download the same file directly using wget, it gets downloaded as:

[theta@boolean-pc ~]$ wget http://mirror.csclub.uwaterloo.ca/archlinux/core/os/i686/core.db.tar.gz
--2010-03-26 15:06:14--  http://mirror.csclub.uwaterloo.ca/archlinux/core/os/i686/core.db.tar.gz
Resolving proxy.iist.ac.in... 172.20.0.211
Connecting to proxy.iist.ac.in|172.20.0.211|:80... connected.
Proxy request sent, awaiting response... 200 OK
Length: 36869 (36K) [application/x-gzip]
Saving to: "core.db.tar.gz"

100%[======================================>] 36,869      38.6K/s   in 0.9s    

2010-03-26 15:06:21 (38.6 KB/s) - "core.db.tar.gz" saved [36869/36869]

Someone please help with this. I have been stuck with this problem for the past 3 days.

daba · 2010-03-26 10:52:13

Is wget configured to use your local proxy? Stupid question. I can see it is in your last message. Does your local proxy use the same nameserver to resolve domain names as your local machine or does it use another nameserver? What does route tell you? Does sudo wget http://mirror.csclub.uwaterloo.ca/archl … .db.tar.gz also download the packet for you?

SERVFAIL means the that the DNS you contact cannot resolve the domainname for you. Most likely the nameservers running on 172.0.0.253 and 172.0.0.211 are not configured correctly but your proxy on 172.0.0.211 does not use them to resolve host names but more likely the DNS provided by your uplink provider directly which seem to work fine.

Last edited by daba (2010-03-26 10:55:12)

n00bface · 2010-03-26 22:02:15

this worked for me check your /etc/hosts.allow if like me on the default install you clicked thru you need to add this

sshd: ALL

to that file. Should allow you to connect now. Only took me about a good hour to figure that one out lol

Nepherte · 2010-03-27 13:05:20

I'm sorry but what does incoming ssh connections have to do with installing packages or outgoing connections? I'd say nothing?

theta · 2010-03-27 17:11:10

daba wrote:

Is wget configured to use your local proxy? Stupid question. I can see it is in your last message. Does your local proxy use the same nameserver to resolve domain names as your local machine or does it use another nameserver? What does route tell you? Does sudo wget http://mirror.csclub.uwaterloo.ca/archl … .db.tar.gz also download the packet for you?
SERVFAIL means the that the DNS you contact cannot resolve the domainname for you. Most likely the nameservers running on 172.0.0.253 and 172.0.0.211 are not configured correctly but your proxy on 172.0.0.211 does not use them to resolve host names but more likely the DNS provided by your uplink provider directly which seem to work fine.

No, "sudo wget" gives the same error while invoking wget as the without sudo works.
Now I presume that thats the main problem but still don't know its solution.

Arch Linux

#1 2010-03-21 06:16:02

Network Problem: Destination Host Unreachable

#2 2010-03-21 16:29:16

Re: Network Problem: Destination Host Unreachable

#3 2010-03-24 16:43:29

Re: Network Problem: Destination Host Unreachable

#4 2010-03-24 18:39:11

Re: Network Problem: Destination Host Unreachable

#5 2010-03-24 20:03:34

Re: Network Problem: Destination Host Unreachable

#6 2010-03-25 17:46:46

Re: Network Problem: Destination Host Unreachable

#7 2010-03-26 09:37:07

Re: Network Problem: Destination Host Unreachable

#8 2010-03-26 10:52:13

Re: Network Problem: Destination Host Unreachable

#9 2010-03-26 22:02:15

Re: Network Problem: Destination Host Unreachable

#10 2010-03-27 13:05:20

Re: Network Problem: Destination Host Unreachable

#11 2010-03-27 17:11:10

Re: Network Problem: Destination Host Unreachable

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