I recently had a case in which customer found trouble in configuring an L2TP over IPSEC tunnel between a second generation AR , AR 19-10 and a USG.
As you probably know, AR19-10 is at the end of production and the product documentation cannot be found so easily. Given the fact that the configuration on this router is slightly different than on AR G3 I would like to post a configuration example for the scenario described in the title.
As shown in the picture bellow,Enterprise branch and HQ are connected one USG and one AR19-10. The networking requirements are as follows:
An L2TP tunnel can be established between USG2000 and AR-10, and the data is between the two networks is encrypted by IPSec.
Enterprise branch netowrk (192.168.10.0/24) is connected to vlanif 1 on AR19-10.
HQ network (192.168.2.0/24) is connected to vlanif 1 on firewall.
USG 2000 and AR19-10 are reachable to each other.