Cisco Simple GRE Tunnels (With IPSEC)
KB ID 0000951 Problem I’ve spent years setting up VPN tunnels between firewalls. The only time I’ve ever dealt with GRE is for letting VPN client software though firewalls. GRE’s job is to ‘encapsulate’ other protocols and transport those protocols inside a virtual point to point link. Below is the topology, I’m going to use. The tunnel will run form Router R1 to Router R3, once complete I should be...
Cisco – Configuring Dynamic Multipoint Virtual Private Networks DMVPN
KB ID 0000954 Problem A while back I uploaded a run through on how to deploy GRE tunnels and protect those tunnels with IPsec. That point-to-point GRE tunnel is a good solution, but if you have a lot of sites it’s not a solution that scales very well. Yes you can have 2147483647 tunnel interfaces, but good luck manually configuring all those tunnels and even if you did, if you want each of your remote sites to talk to each other...
Cisco ASA – Configuring for NTP
KB ID 0000608 Problem With NTP, there will be two things you want to do, 1) Allow a device behind the ASA to take its time from a public NTP server, and 2) Set the ASA to take its system time from a public NTP sever (for accurate date stanps on the logs, and for time critical things like Kerberos authentication.) Solution Allow internal host(s) to get system time though the firewall. 1. Connect to the ASA, go to “enable...