We have installed linux redhat 5 server to for intranet mail service. I am facing a problem while pinging my router i.e. 18.104.22.168. on the other hand I am able to ping this ip from my laptop and other machine and also able to telnet. But when accessing from REDHAT5 we are not able to ping and status is "destination host unreachable..". this router is a getway to our second plant i.e. plant2 and we have got vpn between two network. From plant2 user is able to ping the router IP i.e. 22.214.171.124 and also able to ping my laptop ip ie. 126.96.36.199. our subnet mask is 255.255.255.0 Pl. help me to resolve this issue, thanks.