I have about 10 linux boxes in my network & I am able to ping each other
except for 2 boxes A and B. These boxes can ping other boxes but cannot
ping each other.

I checked the /etc/hosts.deny file & there are no entries in this file on both
boxes A and B. What are the things that I should be checking to fix this ?

I am a software developer & not a linux/network administrator.

How is your network topology?

Have you tried to link 2 box with cross wire ?
and then ping each aother if it's ok the problem
may not invlove with your linux box.

What are the ipaddress for all of the computers on your network as well as the subnets?

I ask this because if your IP addresses for machines A and B have a different number for the any of the numbers sets other then that last AND your subnet is set to 255.255.255.0, you will NOT be able to ping. For example, if A has an ip of 10.0.1.2 and B has 10.0.1.3 and both have a subnet of 255.255.255.0 they will be able to ping each other; however, if C has ip: 10.0.2.3 then C will not beable to ping A nor B and vice versa. To fix this, change the subnet to 255.255.0.0 then it will allow a different number in the third number in the ipaddress.

All my boxes have the IP addresses from <X>.<Y>.<Z>.54 to <X>.<Y>.<Z>.61

A and B are not able to ping each other.

C is able to ping A and vice-versa.
C is able to ping B and vice-versa.

Found the following by running /sbin/ifconfig.

A: inet addr:10.205.20.56 Bcast:10.205.21.255 Mask:255.255.254.0
B: inet addr:10.205.20.57 Bcast:10.205.20.56 Mask:255.255.254.0
C: inet addr:10.205.20.54 Bcast:10.205.20.54 Mask:255.255.254.0

It looks like Bcast for all my machines is the same as the box's inet addr except for machines A and B.
Is this a problem and if it is a problem how can it be fixed ?

Hi

How about /etc/host file ?? . There must be an entry in this file for both machines .
Also this entry must be included in host.equiv .