We have a customer who has 3 sites. Two sites have a Cisco 877-SEC-K9 and the other site has a Draytek 2800. All three sites have full-meshed VPNs. The sites that have Cisco routers are configured to use a GRE VPN tunnel whereas when connecting to the Draytek router site, an IOS IPSEC tunnel has been configured. These VPNs are all working.
However, recently the client has requested to have remote access into one of the sites that have a Cisco 877. Therefore we decided to implement Cisco VPN client configuration onto the router. Once the configuration was uploaded, the GRE tunnels continued to be active whereas the IOS IPsec tunnels to the Draytek were showing as DOWN-NEGOTIATING. Once the Cisco VPN client configuration was removed, these VPNs became active again.
I have attached the configurations both before and after adding the Cisco VPN client commands on the Cisco 877-SEC-K9 router.
I would be grateful for any feedback on what might be going wrong!!