Configuring Resilient Ethernet Protocol

Resilient Ethernet Protocol (REP) is a Cisco propietary protocol which allows you to build redundant Ethernet rings. It’s an alternative to Spanning-Tree protocol and also avoids bridging loops or responds to link failures.
Compared to STP, it offers a faster convergence time (< 300ms) and gives you a simple VLAN load-balancing method.
In our example, we interconnect [...]

Well-known multicast addresses

A lot of dynamic routing protocols uses ip multicast for neighbor discovery, hellos and other things.
Here are some well known multicast adresses:

224.0.0.1 all hosts on a subnet
224.0.0.2 all routers on a subnet
224.0.0.4 Distance Vector Multicast Routing Protocols (DVMRP)
224.0.0.5 OSPF routers
224.0.0.6 OSPF designated routers
224.0.0.9 RIP Version 2 routers
224.0.0.10 EIGRP routers
224.0.0.13 Protocol independent Multicast (PIM) routers