Cisco Simple GRE with IPSEC Tunnels
GRE 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...
Cisco – Configuring Dynamic Multipoint Virtual Private Networks DMVPN
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...
Implementing GDOI into DMVPN
GDOI into DMVPN KB ID 0000956 Problem Just recently I covered DMVPN, which is a great scalable system for adding new sites to your network infrastructure and have them join an existing VPN solution without the need to add extra config at the ‘hub’ site. One of the advantages of DMVPN is it maintains VPN connections from your ‘Spoke’ sites back to the ‘Hub’ site, but if a spoke site needs to speak...
Cisco ASA – Remote VPN Client Internet Access
VPN Client Internet Access KB ID 0000977 Problem I have answered a lot of questions in forums, that are worded something like, “When I have a remote client connected to my firewall VPN they lose Internet access!” Traditionally that’s exactly what the ‘default’ remote VPN Internet access (IPSEC or AnyConnect) gave you. To ensure your remote VPN clients can access the Internet you have two options. The...
Cisco ASA Remote Management via VPN
ASA Remote Management KB ID 0000984 Problem It’s been ages since I has to do this, I usually just manage firewalls via SSH from outside. But I was out on a client site last week and needed to connect to to my ASA, so I simply connected in via AnyConnect; Note: The same procedure is applicable if you are an IPSEC VPN client, L2TP VPN client, or simply coming in over a site to site VPN link. And attempted to SSH, no joy, I tried...