Cisco 3825 Software Configuration Guide - Page 17

Chapter 1 Overview of the Cisco 3825 Mobile Wireless Edge Router Cisco IOS Software Features Software Features Standard Cisco IOS software features supported in the Cisco 3825 router for the RAN-O implementation include: Simple Services • DHCP • PPP • NAT • OSPF • RIP Intelligent Services • QoS • VPN • IP Multicast • Mobile IP/FA • content caching • MPLS • L2TPv3 Other Services • ACFC and PFC Handling During PPP Negotiation • HSRP • NTP • SNMP Redundancy Support In a RAN-O application, to ensure availability, the backhaul links to a Cisco 3825 router are redundantly cabled to the Cisco 2-port T1/E1-RAN card. This card, designed specifically for the Cisco MWR 1941-DC-A router and Cisco 3825 router includes relays that activate the T1/E1 ports. These relays allow "Y" cabling for router redundancy where the T1/E1 link is not redundant and default to open. The relays are controlled by HSRP/redundancy protocol between the two routers connected to the same T1/E1. HSRP Note If you choose to use the Cisco 3825 router in a non-redundant configuration, you must close the relays on the card using the standalone subcommand. Also, redundancy parameters are processed when the router is booted up. These parameters cannot be changed "on the fly." Cisco's HSRP is used to control which router is active and which is standby. HSRP uses a priority scheme to determine which HSRP-configured router is to be the default active router. Priority is determined first by the configured priority value, then by the IP address. In each case, a higher value is of greater priority. OL-15667-03 Cisco 3825 Mobile Wireless Edge Router Software Configuration Guide 1-7