Rate Limiting of RPF Failure Traffic
When you enable rate limiting of packets that fail the RPF check (non-RPF packets), most non-RPF packets are dropped in hardware. According to the multicast protocol specification, the router needs to receive the non-RPF packets for the PIM assert mechanism to function properly, so all non-RPF packets cannot be dropped in hardware. When a non-RPF packet is received, a NetFlow entry is created for each non-RPF flow. When the first non-RPF packet arrives, the PFC bridges the pa..
The ultimate solution to rapidly growing Internet routing tables and IPv4 address depletion was the development of IPv6, which defines 128-bit source and destination addresses. At the risk of being derided 20 years from now, I’ll venture a guess that IPv6 has more addresses than we’ll ever need. IPv6 can support over a trillion, trillion IP addresses per person on the planet—with plenty of publicly routable addresses for everyone. Plus, the structure is well established..
Load Balancing Across PortChannels
When a switch decides to forward a frame out a PortChannel, the switch must also decide which physical link to use to send each frame. To use the multiple links, Cisco switches load balance the traffic over the links in an EtherChannel based on the switch’s global load-balancing configuration. Load-balancing methods differ depending on the model of switch and software revision. Generally, load balancing is based on the contents of the Layer 2, 3, and/or 4 headers. If load ..
Integrated Services Digital Network (ISDN) is used by telephone companies to carry digitized voice and data over the existing telephone system. ISDN has emerged as one of the leading technologies for telecommuting and remote office connection into the corporate headquarters. On the seven layer model, ISDN operates at the physical, data link, and network layers. ISDN basic rate interface (BRI) provides two barrier channels (commonly referred as B channels). Each of these B ch..
Extended IP access-lists can also filter based on application information, such as protocol and port numbers: Router1#configure terminalEnter configuration commands, one per line. End with CNTL/Z.Router1(config)#access-list 151 permit tcp any any eq wwwRouter1(config)#access-list 151 deny tcp any any gt 1023Router1(config)#access-list 151 permit icmp any anyRouter1(config)#access-list 151 permit udp any any eq ntpRouter1(config)#access-list 151 deny ip any anyRouter1(co..
