Here's a nifty way of figuring out if you have IP conflicts on a network ( yum search arp-scan ) :

[root@mbpc-pc ~]# arp-scan -I bond0 -l
Interface: bond0, datalink type: EN10MB (Ethernet)
Starting arp-scan 1.9 with 512 hosts (http://www.nta-monitor.com/tools/arp-scan/)
192.168.0.1     f8:11:11:bc:47:8a       TP-LINK TECHNOLOGIES CO., LTD.
192.168.0.2     54:e6:fc:fb:ad:06       TP-LINK TECHNOLOGIES CO., LTD.
192.168.0.11    90:e6:b4:c6:7d:35       ASUSTek COMPUTER INC.
192.168.0.12    00:21:dc:cc:64:f4       Flextronics International
192.168.0.13    94:de:80:73:b1:78       GIGA-BYTE TECHNOLOGY CO.,LTD.
192.168.0.15    14:da:19:19:95:b5       ASUSTek COMPUTER INC.
192.168.0.10    28:5d:60:ca:44:1c       Azurewave Technologies, Inc.

8 packets received by filter, 0 packets dropped by kernel
Ending arp-scan 1.9: 512 hosts scanned in 3.460 seconds (147.98 hosts/sec). 7 responded
[root@mbpc-pc ~]#

Cheers,
Tom