Switching

69

The spanning tree algorithm ensures that the extended LAN contains no loops and that all LANs are connected by:

Detecting the presence of loops and automatically computing a logical loop-free portion of the topology, called a spanning tree. The topology is dynamically pruned to a spanning tree by declaring the ports on a switch redundant, and placing the ports into a ‘Blocking’ state.

Automatically recovering from a switch failure that would partition the extended LAN by reconfiguring the spanning tree to use redundant paths, if available.

Spanning Tree and Rapid Spanning Tree Port States

If STP is running in STANDARD mode, then each port can be in one of five Spanning Tree states, and one of two switch states. If STP is running in RAPID mode, then each port can be in one of four states. The state of a switch port is taken into account by STP. To be involved in STP negotiations, STP must be enabled on the switch, the port must be enabled on the switch, and enabled for the STP it belongs to.

IP Switching

The switch performs IP routing at wire speed between VLANs that have been configured as IP interfaces. For example, to add the admin VLAN as an IP interface, giving it an IP address of 192.168.163.39 in the subnet 192.168.163.0, first enable IP using the command:

ENABLE IP

Then use either of the following commands:

ADD IP INTERFACE=vlan-admin IPADDRESS=192.168.163.39

MASK=255.255.255.0

ADD IP INTERFACE=vlan11 IPADDRESS=192.168.163.39

MASK=255.255.255.0

The command:

SHOW IP INTERFACE

displays the interfaces enabled for IP routing (Figure 12).

For detailed information about configuring IP, see the Internet Protocol (IP) chapter in the AT-8700XL Series Software Reference.

Figure 12: Example output from the SHOW IP INTERFACE command.

Interface

Type

IP Address

Bc Fr PArp

Filt

RIP Met.

SAMode

IPSc

Pri. Filt

Pol.Filt

Network Mask

MTU VJC

GRE

OSPF Met.

DBcast

Mul.

--------------------------------------------------------------------------------

LOCAL

-

Not Set

-

n

-

---

-

-

--

---

----

-

-

 

-

---

-

-

---

vlan11

Static

192.168.163.39

1

y

On

---

01

Pass

--

---

---

255.255.255.0

1500

-

---

0000000001

No

On

--------------------------------------------------------------------------------

Software Release 2.6.1 C613-02030-00 REV B

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Image 69
Allied Telesis at-8700xl series switch manual IP Switching, Spanning Tree and Rapid Spanning Tree Port States

at-8700xl series switch specifications

Allied Telesis AT-8700XL Series Switches are sophisticated networking devices designed to meet the demanding requirements of modern enterprise environments. These managed Ethernet switches are optimized for reliability, performance, and scalability, making them ideal for various applications, from small businesses to large-scale networks.

One of the standout features of the AT-8700XL series is its robust Layer 2 and Layer 3 capabilities. This versatility allows the switches to perform both basic switching and advanced routing functions, facilitating efficient data traffic management. The series supports a wide range of standard protocols, including VLANs, STP, and RSTP, ensuring smooth and flexible network segmentation.

Another critical characteristic is the series' high-speed connectivity options. With multiple Gigabit Ethernet ports, the AT-8700XL series can handle significant data loads, ensuring seamless communication between connected devices. Furthermore, some models within the series offer 10 Gigabit uplink ports, providing the necessary bandwidth to connect to core networks or high-speed servers.

The AT-8700XL series incorporates advanced Quality of Service (QoS) features that enable network administrators to prioritize traffic effectively. This is particularly crucial for applications sensitive to latency, such as VoIP and video conferencing. By ensuring that time-sensitive data packets are transmitted promptly, the switches help maintain optimal performance across the entire network.

Power over Ethernet (PoE) support is yet another advantage of the AT-8700XL series. This feature allows the switches to deliver power to connected devices, such as IP cameras and wireless access points, via the Ethernet cable. This capability simplifies installations by reducing the need for additional power sources, ultimately saving on costs and improving efficiency.

Security is paramount in any network, and the AT-8700XL series does not disappoint. The switches employ robust security protocols, including Access Control Lists (ACLs), MAC address filtering, and DHCP snooping, to protect against unauthorized access and ensure network integrity.

In summary, Allied Telesis AT-8700XL Series Switches offer a comprehensive solution for various networking needs. With their Layer 2 and Layer 3 capabilities, high-speed connectivity, QoS features, PoE support, and security measures, these switches are well-equipped to enhance network efficiency and reliability, making them an excellent choice for organizations looking to future-proof their infrastructure. The AT-8700XL series exemplifies Allied Telesis's commitment to delivering high-quality networking solutions that cater to the evolving demands of businesses today.