There are some anomalies on a Virtuozzo virtualized Debian 4 (I know, I'm gonna upgrade this one asap, but there dependences). We run some Websites on this one. And a view Days ago exmi4 wasnt able to send mails to SOME people. I'll use live.com as exampledomain!

So some of this people got mails and some didn't.
Some of the mails got stuck in the queue, and after 2 days they went out!!
My Nagios never showed problems with the internet connection or disk space

Now i wanted to install "dig" to look how he's solving the dns request. And this Debian tells me he doesn't know dig..

Long story made short, Debian is able to download sites with exact IP or even with wget live.com, but it is not able to ping live.com.

I'm 99% sure that the networking is right and the routing too!

Some examples of my tring below:

wget live.com

downloads the site

ping live.com
ping http://www.live.com
ping http://live.com

returns:

ping: unknown host live.com

EDIT:

i now use heise.de not live.com any more.
and i found out i can ping the heise.de server by using it's IP-address.

myserver:~# ping 193.99.144.85
PING 193.99.144.85 (193.99.144.85) 56(84) bytes of data.
64 bytes from 193.99.144.85: icmp_seq=1 ttl=248 time=12.7 ms
64 bytes from 193.99.144.85: icmp_seq=2 ttl=248 time=12.6 ms
64 bytes from 193.99.144.85: icmp_seq=3 ttl=248 time=12.9 ms
64 bytes from 193.99.144.85: icmp_seq=4 ttl=248 time=13.1 ms
64 bytes from 193.99.144.85: icmp_seq=5 ttl=248 time=13.1 ms

--- 193.99.144.85 ping statistics ---
5 packets transmitted, 5 received, 0% packet loss, time 4001ms
rtt min/avg/max/mdev = 12.671/12.924/13.163/0.238 ms

EDIT 2:

myserver:/etc/apt# dig heise.de

; <<>> DiG 9.3.4-P1.2 <<>> heise.de
;; global options:  printcmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 40551
;; flags: qr rd ra; QUERY: 1, ANSWER: 1, AUTHORITY: 5, ADDITIONAL: 3

;; QUESTION SECTION:
;heise.de.                      IN      A

;; ANSWER SECTION:
heise.de.               2266    IN      A       193.99.144.80

;; AUTHORITY SECTION:
heise.de.               1622    IN      NS      ns.pop-hannover.de.
heise.de.               1622    IN      NS      ns.s.plusline.de.
heise.de.               1622    IN      NS      ns.plusline.de.
heise.de.               1622    IN      NS      ns2.pop-hannover.net.
heise.de.               1622    IN      NS      ns.heise.de.

;; ADDITIONAL SECTION:
ns.plusline.de.         265     IN      A       212.19.48.14
ns.pop-hannover.de.     5113    IN      A       193.98.1.200
ns2.pop-hannover.net.   15150   IN      A       62.48.67.66

;; Query time: 2 msec
;; SERVER: 193.200.112.80#53(193.200.112.80)
;; WHEN: Tue Oct  9 13:03:50 2012
;; MSG SIZE  rcvd: 216