Network is unreachable after applying kernel patches to Red Hat Enterprise Linux 5 server?

Issue

• Server is not accessible via SSH but able to ping in the network after applying following patches:

RHBA-2012:
1.  1155-1  initscripts bug fix update
2.  1323-1  Important:  kernel security and bug fix update
3.  1335-1  xorg-x11-server bug fix update
4.  1140-1  Moderate: dhcp security update
5.  1271-1  linuxwacom bug fix update
6.  1191-1  xorg-x11-server bug fix update   <not installed>
7.  1149-1  Moderate: sudo security and bug fix update
8.  1361-1  Critical: xulrunner security update
9.  1174-1  Low:kernel security and bug fix update
10. 1270-1  sudo bug fix update
11. 1267-1  Important: bind security and bug fix update
12. 1288-1  Moderate:  libxml2 security update
13. 1224-1  cyrus-sasl bug fix update
14. 1249-1  ipsec-tools bug fix update
15. 1255-1  Moderate: libexif security update
16. 1272-1  kexec-tools bug fix update
17. 1363-1  Important: bind security update
18. 1090-1  Moderate: nss and nspr security, bug fix, and enhancement
19. 1350-1  Critical: firefox security and bug fix update
20. 1265-2  Important: libxslt security update
21. 1101-1  tzdata enhancement update
22. 1097-1  Moderate: glibc security and bug fix update
23. 1123-1  Important: bind security update <not intalled>
24. 1338-1  tzdata enhancement update
25. 1160-1  sudo bug fix update
26. 1207-1  Moderate: glibc security and bugfix update
27. 1256-1  Moderate: ghostscript security update