Data Sheet

Virtual Router Redundancy Protocol (VRRP) provides
backup for any statically allocated next-hop router
address going down, based on RFC 3768 (IPv4)
• VRRP is based on the concept of having more than one router recognize the same router IP address
• VRRP increases the availability of the default path without requiring conguration of dynamic routing, or
router discovery protocols on end stations
• Multiple virtual routers can be dened on any single router interface
• One of the routers is elected the master router and handles all trafc sent to the specied virtual router IP
address
• When the master router fails, one of the backup routers is elected in its place and starts handling trafc sent
to the address
As an enhancement to RFC 3768, VRRP Interface
can be congured as pingable to help troubleshoot
network connectivity issues
• In that case, VRRP master responds to both fragmented and unfragmented ICMP echo requests packets
destined to VRRP address(es)
• VRRP master responds with VRRP address as the source IPv4 address and VRMAC as the source MAC address
• A virtual router in backup state discards these ICMP echo requests
VRRP Route/Interface Tracking feature extends the
capability of the Virtual Router Redundancy Protocol
(VRRP)
• Allows tracking of specic route/interface IP states, within the router, that can alter the priority level of a
virtual router for a VRRP group
• It ensures the best VRRP router is master for the group
Router Discovery Protocol is an extension to ICMP
and enables hosts to dynamically discover the IP ad-
dress of routers on local IP subnets
• Based on RFC 1256 for IPv4
• Routers periodically send router discovery messages to announce their presence to locally-attached hosts
• The router discovery message advertises one or more IP addresses on the router that hosts can use as their
default gateway
• Hosts can send a router solicitation message asking any router that receives the message to immediately
send a router advertisement
• Router discovery eliminates the need to manually congure a default gateway on each host
• It enables hosts to switch to a different default gateway if one goes down
Loopback interfaces are available as dynamic, stable IP addresses for other devices on the network, and for routing protocols
Tunnel interfaces are available for IPv4 and IPv6 • Each router interface (port, or VLAN interface) can have multiple associated tunnel interfaces
• Support for Congured 6to4 (RFC 4213) and Automatic 6to4 tunneling (RFC 3056) for IPv6 trafc
encapsulation into IPv4 packets
• 6to4 tunnels are automatically formed for IPv4 tunnels carrying IPv6 trafc
• M4300 can act as a 6to4 border router that connects a 6to4 site to a 6to4 domain
Support of Routing Information Protocol (RIPv2) as
a distance vector protocol specied in RFC 2453 for
IPv4
• Each route is characterized by the number of gateways, or hops, a packet must traverse to reach its intended
destination
• Categorized as an interior gateway protocol, RIP operates within the scope of an autonomous system
Route Redistribution feature enables the exchange
of routing information among different routing
protocols all operating within a router
• Congurable when different routing protocols use different ways of expressing the distance to a destination
or different metrics and formats
• For instance, when OSPF redistributes a route from RIP, and needs to know how to set each of the route’s
path attributes
Open Shortest Path First (OSPF) link-state protocol for
IPv4 and IPv6
• For IPv4 networks, OSPF version 2 is supported in accordance with RFC 2328, including compatibility mode
for the RFC 1583 older specication
• For IPv6 networks, OSPF version 3 is fully supported
• OSPF can operate within a hierarchy, the largest entity within the hierarchy is the autonomous system (AS)
• An AS is a collection of networks under a common administration sharing a common routing strategy
(routing domain)
• An AS can be divided into a number of areas or groups of contiguous networks and attached hosts
• Two different types of OSPF routing occur as a result of area partitioning: Intra-area and Inter-area
• Intra-area routing occurs if a source and destination are in the same area
• Inter-area routing occurs when a source and destination are in different areas
• An OSPF backbone distributes information between areas
Intelligent Edge Managed Switches
Data Sheet | M4300 series
PAGE 12 of 60