MVPN Configuration Guidelines and Restrictions
When configuring MVPN, follow these guidelines and restrictions: • All PE routers in the multicast domain need to be running a Cisco IOS software image that supports the MVPN feature. There is no requirement for MVPN support on the P and CE routers. • Support for IPv4 multicast traffic must also be enabled on all backbone routers. • The Border Gateway Protocol (BGP) routing protocol must be configured and operational on all routers supporting multicast traffic. In add..
Frame Relay and ATM support a single bit that can be set for QoS purposes, but these single bits are intended for a very strict use related to drop probability. Frames or cells with these bits set to 1 are considered to be better candidates to be dropped than frames or cells without the bit set to 1. Named the Frame Relay Discard Eligibility (DE) bit and the ATM Cell Loss Priority (CLP) bit, these bits can be set by a router, or by an ATM or Frame Relay switch. Router and sw..
Routing Policy and the BGP Decision Algorithm
A BGP router may receive paths for the same route from many neighbors. How the best path is selected is a matter of local policy. The policy within an AS must be consistent; otherwise, routing loops could occur. Conceptually, the policy and decision process is shown in Figure 11-16. Figure 11-16. BGP's Policy and Decision Process An incoming Routing Information Base is maintained for each peer. Incoming policy is applied to each RIB, and complying routes are p..
Four-Step STP Decision Sequence
When creating a loop-free logical topology, Spanning Tree always uses the same four-step decision sequence: • Lowest Root BID • Lowest Path Cost to Root Bridge • Lowest Sender BID • Lowest Port ID Bridges pass Spanning Tree information between themselves using special frames known as bridge protocol data units (BPDUs). A bridge uses this four-step decision sequence to save a copy of the best BPD..
Setting the Router As the NTP Master for the Network
There is no need for a dedicated NTP server; you can pick one or two routers to act as authoritative NTP servers for the whole network. (The router should have a calendar function): Router#configure terminal Enter configuration commands, one per line. End with CNTL/Z. Router(config)#clock timezone EST 5 Router(config)#clock summer-time EDT recurring Router(config)#clock calendar-valid Router(config)#ntp master 8 Router(config)#end Router# When no authoritative time s..
