There is a three node cluster .While connecting through telnet to logical ip address not connecting

We have a 3 node Suncluster configured with nodes named M4000, M50001 & M50002, The resource group named "k-sybase-rg" is designed to run and failover between nodes M4000 and M50002

root@M4000 # clrg status k-sybase-rg
=== Cluster Resource Groups ===
Group Name Node Name Suspended Status
---------- --------- --------- ------
k-sybase-rg M4000 No Online
M50002 No Offline

The resources defined in this resource group are :
root@M4000 # clrs list -g kplus-sybase-rg
k-lh
k-hastp-rs
k-sybase-rs
k-app-rs

Issue :
Whenever there is a failover of this resource group (k-sybase-rg ) from M4000 to M50002 and again failback to M4000, all the listening ports on 10.x.x.156 stops responding from M50002 node