40
LAN configuration
Spanning Tree
The Spanning Tree Protocol (STP) can be used to detect and disable network loops, and to
provide backup links between switches and routers. Enabling STP allows the router to interact
with other STP-compliant switches and routers on the network to ensure that only one route
exists between any two stations on the network, and provide backup links which automatically
take over when a primary link goes down. The router supports STP (IEEE 802.1D) and Rapid
STP (IEEE 802.1w).
•
Spanning Tree Protocol: STP uses a distributed algorithm to select a switch or router that
serves as the root of the spanning tree network. It selects a root port on each device (except
for the root device) that incurs the lowest path cost when forwarding a packet from that
device to the root device. Then it selects a designated device from each LAN that incurs the
lowest path cost when forwarding a packet from that LAN to the root device. All ports
connected to designated devices are assigned as designated ports. After determining the
lowest cost spanning tree, it enables all root ports and designated ports, and disables all
other ports. Network packets are therefore only forwarded between root ports and
designated ports, eliminating any possible network loops.
Once a stable network topology has been established, all devices listen for Hello BPDUs
(Bridge Protocol Data Units) transmitted from the root device (Root Bridge). If a device does
not get a Hello BPDU after a predefined interval (Maximum Age), the device assumes that
the link to the Root Bridge is down. This device will then initiate negotiations with other
devices to reconfigure the network to re-establish a valid network topology.
•
Rapid Spanning Tree Protocol: RSTP is designed as a general replacement for the slower,
legacy STP. RSTP achieves much faster reconfiguration (around 1 to 3 seconds, compared
to 30 seconds or more for STP) by reducing the number of state changes before active ports
start learning, predefining an alternate route that can be used when a node or port fails,
and retaining the forwarding database for ports insensitive to changes in the tree structure
when reconfiguration occurs.
Note
The router includes some fixed (not configurable) STP parameters, including the Hello Time (set
to 2 seconds) and Forward Delay (set to 4 seconds).
DHCP client list
The DHCP Clients List displays the IP address, host name, MAC address, and client type for
each client that has requested an IP address since the last reboot of the router, and for clients
with static leases.
Click
Manual Assignment
to reserve the dynamically assigned IP address for a specific
computer as a static lease. A maximum of 32 leases can be defined.
Содержание R100-Series
Страница 6: ...6 ...
Страница 10: ...10 Deploying the HP R110 R120 ...
Страница 44: ...44 LAN configuration ...
Страница 80: ...80 VPN configuration ...
Страница 88: ...88 Routing configuration ...
Страница 98: ...98 Firewall configuration ...
Страница 130: ...130 Tools ...
Страница 134: ...134 ...
Страница 142: ...142 ...