I have a PPTP connection to a remote site that has has a tunnel to another site. I am unable to reach some endpoints on the tunneled-to site, and get a duplicate ACK error when I try to.
I have the main site with two bridges, for voice and data. Each satellite office has two bridges as well, in the same configuration. Voice is carried on VLAN 20 for all offices. L2TP is used to connect the offices, with EOIP tunnels terminating in the voice bridge at each location, along with a VLAN 20 interface. DHCP for the voice network is then done entirely from the main office, and the whole voice network is a flat 10.100.x.x/16. The data network for each office is one of 192.168.n.x/24, where ‘n’ increments for each new office. This works fine.
When I VPN to the main office, I am unable to reach some devices on the satellite office’s voice bridges. In wireshark, I see a duplicate ACK. Attached is a capture demonstrating this. Let me know if you need to see any configs. I have proxy-arp enabled on the voice bridge at the main office, where the VPN connection resides. Satellite offices do not have proxy-arp enabled. I do not know if I can reach these devices while on site, but I am going to be attempting this soon.
ackdup.cap.zip (2.32 KB)