Specifications

6
WWW.EXTREMENETWORKS.COM
Switching: Network Resiliency and
Forwarding Control
Layer 2+
For network resiliency, ExtremeXOS oers a choice
between standard protocols and more advanced Layer 2+
protocols, optimized for faster resiliency, larger scaling and
simpler operation.
Spanning Tree Protocol: ExtremeXOS supports IEEE
802.1D STP, 802.1w RSTP and 802.1s MSTP. In Extreme
Multiple Instance STP mode, ExtremeXOS allows a port or
VLAN to belong to multiple STP domains and therefore
adds flexibility to STP network design, further increasing
resiliency. The implementation is also compatible with
PVST+ and IEEE 802.1Q.
Ethernet Automatic Protection Switching (EAPS, RFC 3619)
allows the IP network to provide the level of resiliency
and uptime that users expect from their traditional voice
network. EAPS is more adaptable than Spanning Tree or
Rapid Spanning Tree protocols and can achieve sub-second
recovery that delivers consistent failover regardless of the
number of VLANs, network nodes or network topology in
Extreme Networks-recommended configurations. EAPS
functionality increases network recovery time, which results
in significant reduction in Voice-over IP call drop rates and
improvement in digital video performance in supported
solution configuration.
Resiliency Features: the Virtual Router Redundancy
Protocol (VRRP) enables a group of routers to function
as a single virtual default gateway. Extreme Standby
Router Protocol™ (ESRP) can be implemented at both
Layers 2 and 3. ESRP tracks link connectivity, VLANs,
learned routes and ping responses. ESRP can be used as
an STP and VRRP substitute, providing simplicity via a
single protocol for Layer 2 and Layer 3 redundancy. Multiple
instances of ESRP in the same VLAN allow direct host
attachment to standby switches.
Virtual Private LAN Services (VPLS, RFC 4762) are used for
signaling and provisioning subscriber VLANs and vMANs
over the IP network core. Extreme’s VPLS implementation
interoperates with EAPS, ESRP, and STP to provide a
connectivity option for delivering fault-tolerant Layer 2
services over a Layer 3 network core.
To further harden the network resiliency protocols of
ExtremeXOS, Extreme Link Status Monitoring (ELSM)
protects the network and resiliency protocols from the
eects of unidirectional links to protocols. For bandwidth
scaling, link aggregation (static and dynamic via LACP)
utilizes the bandwidth of multiple links. IGMP Snooping and
Multicast VLAN Registration preserve network bandwidth
by forwarding only to ports and to VLANs with subscribers
from a single multicast VLAN. If desired, static IGMP
membership allows the force-forwarding of trac through
the network for high subscription response, and filters
provide control over transmitted content.
IPv4
ExtremeXOS also oers a set of Layer 3 switching features
to increase control and management on very large
networks. The switching software implements static routes,
RIP, OSPFv2, IS-IS and BGP4 for External BGP (EBGP) and
Internal BGP (IBGP).
ExtremeXOS fields a rich set of IP multicast routing
protocols, including PIM Dense Mode (PIM-DM), PIM Sparse
Mode (PIM-SM) and PIM Source Specific Multicast (PIM-
SSM), which work hand in hand with the built-in IGMPv1/v2/
v3 support. Multicast source routes can be shared between
sites using MSDP and MBGP, for example, to share sources
of distance learning multicast streams in a university
backbone network. IGMP v2/v3 SSM mapping allows both
IGMPv2 and IGMPv3 in the network, upgrading to the more
powerful and secure IGMPv3 where needed.
Designed for IPv6
IPv6 oers improved network intelligence and a
considerable number of new capabilities over IPv4.
However, there are specific challenges regarding whether
to choose to actively participate in the transition to IPv6 or
hold o to further evaluate. Extreme has taken a ground-up
approach to addressing these challenges by designing IPv6
intelligence into ExtremeXOS from the beginning.
Extreme Networks has designed an architecture for the
performance, flexibility and security requirements of IPv6
without compromising operational simplicity.
Features include Layer 2 and Layer 3 IPv6 forwarding,
Quality of Service (QoS) to provide dierent level of service
to dierent groups of IPv6 trac, routing protocols and
tunnels. ExtremeXOS provides investment protection and
allows a safe and smooth transition by tunneling IPv6 trac
across non-IPv6- aware parts of the network.
ExtremeXOS platforms oer wire-speed ACLs – providing
defense and control over the next generation of IP. Even
when operating with IPv4, ExtremeXOS can harden the
network to attacks using IPv6 transport.