Disadvantage of VPNs

The disadvantages of VPN  are related to implementation troubleshooting  trust and  internet  availability.

a.Implementation  can be time consuming: Implementation a VPN  can  sometimes be difficult  and time  consuming. Configuration planning, management  of keys, and troubleshooting  can easily turn  what seen to be a simple task into weeks of labour.

b.Troubleshooting Problems Because in a VPN data enters a gateway  unlevered  and leaves the gateway encrypted it can be very  difficult to troubleshoot a VPN  problems  such  as key  resynchronization  failures in authentication dropped  packets and gateway load  and stress can all make pinpointing problems  in the VPN  a difficult task.

To make your VPN reliable  make sure the VPN  administrators clearly understand  the underlying software  architecture and  a thorough understanding  of internet  protocols.

c.Vendor Interoperability: Many  vendors offering VPN  solutions long with the complex  nature  of VPN  protocols  such as IP sec  it can  be difficult to get different  vender  solution to interoperate. The  first step in attempting to connect two  vendors. VPN  devices  is to checks  the  VVPN    web site and check  for your  vendor  interoperability. The  second  thing to do is to  make sure you have  the configuration right  between the two.