ping lab machine fail but internet ok
 

My FC3 machine cannot ping nor nslookup the lab machine lab12 (Red Hat Linux 3.3.3-7) fail but the FC3 machine can ping lab12's numerical IP addresses and can access internet successfully.
How to fix this problem?

# ping www.google.com
PING www.l.google.com (64.233.167.147) 56(84) bytes of data.
64 bytes from 64.233.167.147: icmp_seq=0 ttl=246 time=32.2 ms
64 bytes from 64.233.167.147: icmp_seq=1 ttl=246 time=31.3 ms

--- www.l.google.com ping statistics ---
2 packets transmitted, 2 received, 0% packet loss, time 999ms
rtt min/avg/max/mdev = 31.303/31.769/32.235/0.466 ms, pipe 2

# ping lab12
ping: unknown host lab12

# ping 172.29.1.101
PING 172.29.1.101 (172.29.1.101) 56(84) bytes of data.
64 bytes from 172.29.1.101: icmp_seq=0 ttl=63 time=29.1 ms
64 bytes from 172.29.1.101: icmp_seq=1 ttl=63 time=1.49 ms
64 bytes from 172.29.1.101: icmp_seq=2 ttl=63 time=1.44 ms

# nslookup lab12
Server: 172.28.0.5
Address: 172.28.0.5#53

** server can't find lab12: NXDOMAIN

# route
Kernel IP routing table
Destination Gateway Genmask Flags Metric Ref Use Iface
172.28.0.0 * 255.255.0.0 U 0 0 0 eth0
169.254.0.0 * 255.255.0.0 U 0 0 0 eth0
default 172.28.0.2 0.0.0.0 UG 0 0 0 eth0

Add lab12 to the fc3's /etc/hosts, or add lab12 to the dns server.