I'm trying to know, how can I do NAT portmap-based for a group of Asterisk-based VoIP servers, on the inside interfaces of the router, with multiple Internet links.
I have a dual-ISP connection, on a Cisco 2821 with the IOS 14.4(15)T and two HWIC-4ESW. Two default routes are applied. Services (WEB, VOIP, DNS) have been isolated in different vlans.
Each server will have two public IP address and one private address. So, external clients on Internet will have two paths for each server. In the event that one fails, the other takes the entire load. In this case, how BGP4 can improve the efficiency and redundancy of the network? What attributes help?
what type of QoS I can put on the router, in order to ensure SIP and RTP traffic flows?
and What routing best practices can be implemented?
If I install a DNS Server with local IP address, on the inside zone of the network, that serves queries for external clients, the DNS response must be to a Global IP address or may be to a local IP address?
Thanks for all.