Juniper EX3300 Hardware Guide

For more information about strict unicast RPF, see RFC 3704, Ingress Filtering for
Multihomed Networks at http://www.ietf.org/rfc/rfc3704.txt.
Unicast RPF Implementation
This section includes:
•
Unicast RPF Packet Filtering on page 20
•
Bootstrap Protocol (BOOTP) and DHCP Requests on page 20
•
Default Route Handling on page 20
Unicast RPF Packet Filtering
When you enable unicast RPF on the switch, the switch handles traffic in the following
manner:
•
If the switch receives a packet on the interface that is the best return path to the unicast
source address of that packet, the switch forwards the packet.
•
If the best return path from the switch to the packet's unicast source address is not
the receiving interface, the switch discards the packet.
•
If the switch receives a packet that has a source IP address that does not have a routing
entry in the forwarding table, the switch discards the packet.
Bootstrap Protocol (BOOTP) and DHCP Requests
Bootstrap protocol (BOOTP) and DHCP request packets are sent with a broadcast MAC
address and therefore the switch does not perform unicast RPF checks on them. The
switch forwards all BOOTP packets and DHCP request packets without performing
unicast RPF checks.
Default Route Handling
If the best return path to the source is the default route (0.0.0.0) and the default route
points to reject, the switch discards the packets. If the default route points to a valid
network interface, the switch performs a normal unicast RPF check on the packets.
When to Enable Unicast RPF
Enable unicast RPF when you want to ensure that traffic arriving on a network interface
comes from a source that resides on a network that that interface can reach. You can
enable unicast RPF on untrusted interfaces to filter spoofed packets. For example, a
common application for unicast RPF is to help defend an enterprise network from
DoS/DDoS attacks coming from the Internet.
Enable unicast RPF only on symmetrically routed interfaces. A symmetrically routed
interface uses the same route in both directions between the source and the destination,
as shown in Figure 3 on page 21. Symmetrical routing means that if an interface receives
a packet, the switch uses the same interface to send a reply to the packet source (the
receiving interface matches the forwarding-table entry for the best return path to the
source).
Copyright © 2015, Juniper Networks, Inc.20
Network Interfaces for EX4300 Switches

Juniper EX3300 Specifications

General

Ethernet LAN	Yes
Authentication method	RADIUS, TACACS+
Connectivity technology	Wired
Ethernet interface type	Gigabit Ethernet
Number of VLANs	4096
Networking standards	IEEE 802.1ab, IEEE 802.1D, IEEE 802.1Q, IEEE 802.1s, IEEE 802.1w, IEEE 802.1x, IEEE 802.3, IEEE 802.3ab, IEEE 802.3ad, IEEE 802.3x, IEEE 802.3z
Ethernet LAN data rates	10, 100, 1000 Mbit/s
Copper ethernet cabling technology	1000BASE-T, 100BASE-TX, 10BASE-T
Console port	-
ExpressCard slot	No
Fiber ports quantity	4
USB 2.0 ports quantity	0
Basic switching RJ-45 Ethernet ports quantity	48
Throughput	130 Mpps
Number of queues	8
MAC address table	16000 entries
Maximum data transfer rate	176 Gbit/s
Supported data transfer rates	10, 100, 1000Mbps
Switch type	Managed
Switch layer	L2
Security algorithms	SSH-2
Power source	AC
AC input voltage	100 - 240 V
Power consumption (typical)	100 W
Form factor	1U
Product color	Black
Flash memory	1024 MB
Processor frequency	1000 MHz
Compatible operating systems	Junos
Operating altitude	0 - 3049 m
Non-operating altitude	0 - 4877 m
Storage temperature (T-T)	-40 - 70 °C
Operating temperature (T-T)	0 - 45 °C
Storage relative humidity (H-H)	0 - 95 %
Operating relative humidity (H-H)	10 - 85 %
Supported network protocols	IPv6

Weight and Dimensions

Depth	310 mm
Width	437 mm
Height	44 mm
Weight	4900 g