To create access on Cisco router that only allow outgoing tcp connection, and block all incoming traffic, except traffic initiated by incoming users, you need to allow established connection initiated by inside host.

Cisco router can be used as VPN server, using L2TP and IPSec, for client from internet accesing private network.

Cisco router can be used as VPN server, using PPTP, for client from internet accesing private network.

As using route reflector is a way simplifying and scaling iBGP configuration, it is recommended to use if you have many routers in your AS.

Cisco has support EIGRP as PE CPE routing protocol in MPLS VPN.  It is just like another routing protocol using for PE CPE roituing protocol.  The mechanism is common.  EIGRP in PE talk with EIGRP in CPE to exchange routing, then routing receive from CPE is redistribute to MP BGP (multi protocol BGP) running under address family configuration.  EIGRP receive all VPN routing from reditributing form MP BGP (multi protocol BGP) running under address family configuration.

This procedure is used for recover switch 2900, 3500, and 3750 series.
1. Connect to switch with console
2. Unplug power cable
3. Hold down mode button when reconnect the power cable to bring to switch: mode

Sometimes you lost your router password, or you work as network administrator in new places, that no one knows the password of your new company router. Here the procedure for recover the password.

Configuring nat and without nat is pretty simple. It's just configuring nat and global configuration. Nat id correspond with with same global id. For example, you want all traffic from inside interface will be been nat to outside interface ip address when going to internet through outside interface, then you need configure this.

Configuring RIP for routing protocol between PE and CPE on MPLS VPN cover three steps.
1. Configure RIP on CPE
2. Configure RIP on address-family level on MPLS PE
3. Redistribute RIP to BGP vice versa on MPLS PE

Configuring BGP on Cisco router is simple enough. Before start configuring BGP, you need two consideration :
1. BGP only advertise routing entry that exist in IGP routing table
2. BGP is classfull routing protocol, you must include netmask in network statement BGP configuration if the network is not classfull.