VPN over Internal Network & Private address

[J_Vansen_S]

Setup: ISR 1841(remote)---Router---Internet---ASA 5510(HQ)

Requirement: HQ (centralize call processing) extends to Remote Site

I have a ISR1841 connected to inside interface of my customer's Router. ISR1841 will have private IP on its inside & outside interface. Only Router outside interface connected to internet will have Public IP Address.

My doubt is whether the ISR1841 can build VPN tunnel from its private outside IP address.

Is this possible and how? to have this remote site router(ISR 1841) to VPN back to HQ for centralized call-processing service

[Collin Clark]

It can be done, you will need to enable NAT Transparency and you should use UDP if possible. Search for NAT-T on cisco.com for config examples.

HTH and please rate.