H3C S7500 Series Operating instructions

Brand: H3C

Model: S7500 Series

Type: Operating instructions

H3C S7500 Series: Enterprise-grade Ethernet switches, part of H3C's S7500 family, designed for high-performance networking in data centers and large enterprise campus networks. Key capabilities include:

Advanced Layer 2 and Layer 3 Switching: Provides comprehensive Layer 2 and Layer 3 switching features, including VLANs, QoS, and routing protocols, allowing for flexible network segmentation, traffic prioritization, and efficient routing.
High Scalability: Supports stacking technology, enabling multiple switches to be interconnected and managed as a single logical unit, providing scalability and redundancy.

Advanced Layer 2 and Layer 3 Switching: Provides comprehensive Layer 2 and Layer 3 switching features, including VLANs, QoS, and routing protocols, allowing for flexible network segmentation, traffic prioritization, and efficient routing.
High Scalability: Supports stacking technology, enabling multiple switches to be interconnected and managed as a single logical unit, providing scalability and redundancy.

Operation Manual – DLDP

H3C S7500 Series Ethernet Switches Table of Contents

Table of Contents

Chapter 1 DLDP Configuration ....................................................................................................1-1

1.1 Overview............................................................................................................................1-1

1.1.1 Introduction..............................................................................................................1-1

1.2 DLDP Fundamentals .........................................................................................................1-2

1.2.1 DLDP Implementation.............................................................................................1-2

1.2.2 DLDP Status............................................................................................................1-6

1.2.3 DLDP Timers...........................................................................................................1-7

1.2.4 DLDP Operating Mode............................................................................................1-8

1.2.5 DLDP Neighbor State.............................................................................................. 1-8

1.2.6 Link Auto-recovery Mechanism...............................................................................1-9

1.3 DLDP Configuration.........................................................................................................1-10

1.3.1 Configuring DLDP.................................................................................................1-10

1.3.2 Resetting DLDP Status.........................................................................................1-12

1.3.3 Precautions During DLDP Configuration ..............................................................1-13

1.4 DLDP Network Example..................................................................................................1-14

Operation Manual – DLDP

H3C S7500 Series Ethernet Switches Chapter 1

DLDP Configuration

1-1

Chapter 1 DLDP Configuration

When configuring Device Link Detection Protocol (DLDP), go to these sections for

information you are interested in:

z Overview

z DLDP Fundamentals

z DLDP Configuration

z DLDP Network Example

1.1 Overview

1.1.1 Introduction

You may have encountered unidirectional links in networking. When a unidirectional

link occurs, the local device can receive packets from the peer device through the link

layer, but the peer device cannot receive packets from the local device. Unidirectional

link can cause problems such as Spanning Tree Protocol (STP) loops.

Unidirectional links can be caused by

z Fiber cross-connection, as shown in Figure 1-1

z Fibers that are not connected or disconnected, as shown in Figure 1-2, the hollow

lines in which refer to fibers that are not connected or disconnected.

DLDP can detect the link status of an optical fiber cable or copper twisted pair (such as

super category 5 twisted pair). If DLDP finds a unidirectional link, it disables the related

port automatically or prompts you to disable it manually according to the configurations,

to avoid network problems.

SwitchB

SwitchA

GE2/0/3

GE2/0/4

SwitchB

SwitchA

GE2/0/3

GE2/0/4

Figure 1-1 Fiber cross-connection

Operation Manual – DLDP

H3C S7500 Series Ethernet Switches Chapter 1

DLDP Configuration

1-2

SwitchB

SwitchA

GE2/0/3

GE2/0/4

SwitchB

SwitchA

GE2/0/3

GE2/0/4

Figure 1-2 Fiber broken or not connecte

DLDP provides the following features:

z As a link layer protocol, it works together with the physical layer protocols to

monitor the link status of a device.

z The auto-negotiation mechanism at the physical layer detects physical signals and

faults. DLDP identifies peer devices and unidirectional links, and disables

unreachable ports.

z Even if both ends of links can work normally at the physical layer, DLDP can detect

whether these links are connected correctly and whether packets can be

exchanged normally at both ends. However, the auto-negotiation mechanism

cannot implement this detection.

 Note:

z In order for DLDP to detect fiber disconnection in one direction, you need to

configure the port to work in mandatory full duplex mode at a mandatory rate.

z When the port determines the duplex mode and speed through auto-negotiation,

even if DLDP is enabled, it does not take effect when the fiber in one direction is

disconnected. In this case, the port is considered down.

1.2 DLDP Fundamentals

1.2.1 DLDP Implementation

DLDP detects link status by exchanging the following types of packets.

Operation Manual – DLDP

H3C S7500 Series Ethernet Switches Chapter 1

DLDP Configuration

1-3

Table 1-1 DLDP packet types

DLDP packet type Function

Notifies the neighbor devices of the existence of the local

device. An advertisement packet carries only the local port

information, and it does not require response from the peer

end.

RSY-Advertisement

packets (referred to

as RSY packets

hereafter)

Advertisement packet with the RSY flag set to 1. RSY

advertisement packets are sent to request synchronizing the

neighbor information when neighbor information is not

locally available or a neighbor information entry ages out.

Flush-Advertisement

packets (referred to

as flush packets

hereafter)

Advertisement packet with the flush flag set to 1. A flush

packet carries only the local port information (instead of the

neighbor information) and is used to trigger neighbors to

remove the information about the local device.

Probe

Probe packets are used to probe the existence of a neighbor.

Echo packets are required from the corresponding neighbor.

Probe packets carry the local port information. Neighbor

information is optional for probe packets. A probe packet

carrying neighbor information probes the specified

neighbors; A probe packet carrying no neighbor information

probes all the neighbors.

Echo

Response to probe packets. An echo packet carries the

information about the response port and the neighbor

information it maintains. Upon receiving an echo packet, a

port checks whether the neighbor information carried in the

echo packet is consistent with that of itself. If yes, the link

between the local port and the neighbor is regarded as

bidirectional.

Disable

Disable packets are used to notify the peer end that the local

end is in the disable state. Disable packets carry only the

local port information instead of the neighbor information.

When a port detects a unidirectional link and enters the

disable state, the port sends disable packets to the neighbor.

A port enters the disable state upon receiving a disable

packet.

Operation Manual – DLDP

H3C S7500 Series Ethernet Switches Chapter 1

DLDP Configuration

1-4

DLDP packet type Function

LinkDown

Linkdown packets are used to notify unidirectional link

emergencies (a unidirectional link emergency occurs when

the local port is down and the peer port is up). Linkdown

packets carry only the local port information instead of the

neighbor information. In some conditions, a port is

considered to be physically down if the link connecting to the

port is physically abnormal (for example, the Rx line of the

fiber on the port is disconnected, while the Tx line operates

properly). But for the peer end, as Rx signals can still be

received on the physical layer, the port is still considered to

be normal. Such a situation is known as unidirectional link

emergency.

When a unidirectional link emergency occurs, DLDP sends

linkdown packets immediately to inform the peer of the link

abnormality. Without linkdown packets, the peer can detect

the link abnormality only after a period when the

corresponding neighbor information maintained on the

neighbor device ages out, which is three times the

advertisement interval. Upon receiving a linkdown packet, if

the peer end operates in the enhanced mode, it enters the

disable state, and sets the receiving port to the DLDP down

state (auto shutdown mode) or gives an alarm to the user

(manual shutdown mode).

Recover Probe

Recover probe packets are used to detect whether a link

recovers to implement the port auto-recovery mechanism.

Recover probe packets carry only the local port information

instead of the neighbor information. They request for recover

echo packets as the response. A port in the DLDP down

state sends a recover probe packet every two seconds.

Recover Echo

Recover echo packets are response to recover probe

packets in the port auto-recovery mechanism. A link is

considered to restore to the bidirectional state if a port on

one end sends a recover probe packet, receives a recover

echo packet, and the neighbor information contained in the

recover echo packet is consistent with that of the local port.

1) If the DLDP-enabled link is up, DLDP sends DLDP packets to the peer device, and

analyzes/processes the DLDP packets received from the peer device. DLDP

packets sent in different DLDP states are of different types.

Table 1-2 DLDP state and DLDP packet type

DLDP state Type of the DLDP packets sent

Active Advertisement packets, with the RSY flag set or not set.

Advertisement Advertisement packets

Probe Probe packets

Operation Manual – DLDP

H3C S7500 Series Ethernet Switches Chapter 1

DLDP Configuration

1-5

2) A DLDP packet received is processed as follows:

z In authentication mode, the DLDP packet is authenticated and is then dropped if it

fails the authentication.

z The packet is further processed, as described in Table 1-3.

Table 1-3 The procedure to process a received DLDP packet

Packet type Processing procedure

If the corresponding neighbor entry does not

exist on the local device, DLDP creates the

neighbor entry, triggers the entry aging timer,

and switches to the probe state.

packet

Extracts

neighbor

information

If the corresponding neighbor entry already

exists on the local device, DLDP resets the

aging timer of the entry.

Flush packet Removes the neighbor entry from the local device

Creates the neighbor entry if it does not exist

on the local device.

Probe packet

Sends echo

packets

containing both

neighbor and its

own information

to the peer

Resets the aging timer of the entry if the

neighbor entry already exists on the local

device.

No Drops the echo packet

Sets the flag bit of the

neighbor to bidirectional

link

Echo packet

Checks

to see if

the local

device is

in the

probe

state

Yes

Checks to

see if the

neighbor

information

contained

in the

packet is

the same

as that on

the local

device

Yes

If all neighbors are in the

bidirectional link state,

DLDP switches from the

probe state to the

advertisement state, and

sets the echo waiting

timer to 0.

3) If no echo packet is received from the neighbor, DLDP performs the following

processing:

Operation Manual – DLDP

H3C S7500 Series Ethernet Switches Chapter 1

DLDP Configuration

1-6

Table 1-4 Processing procedure when no echo packet is received from the neighbor

No echo packet received from the

neighbor

Processing procedure

In normal mode, no echo packet is

received when the echo waiting timer

expires.

In enhanced mode, no echo packet is

received when the enhanced timer

expires

DLDP switches to the disable state,

outputs log and tracking information, and

sends flush packets. Depending on the

user-defined DLDP down mode, DLDP

disables the local port automatically or

prompts you to disable the port

manually. DLDP sends RSY messages

and removes the corresponding

neighbor entries.

1.2.2 DLDP Status

A link can be in one of these DLDP states: initial, inactive, active, advertisement, probe,

disable, and delaydown.

Table 1-5 DLDP status

Status Description

Initial Initial status before DLDP is enabled.

Inactive DLDP is enabled but the corresponding link is down

Active

DLDP is enabled, and the link is up or an neighbor entry is

cleared

All neighbors communicate normally in both directions, or

DLDP remains in active state for more than five seconds and

enters this status. It is a stable state where no unidirectional link

is found

Probe

DHCP sends packets to check whether the link is a

unidirectional. It enables the probe sending timer and an echo

waiting timer for each target neighbor.

Disable

DLDP detects a unidirectional link, or finds (in enhanced mode)

that a neighbor disappears. In this case, DLDP sends and

receives only recover probe packets and recover echo packets.

DelayDown

When a device in the active, advertisement, or probe DLDP

state receives a port down message, it does not removes the

corresponding neighbor immediately, neither does it changes

to the inactive state. Instead, it changes to the delaydown state

first.

When a device changes to the delaydown state, the related

DLDP neighbor information remains, and the DelayDown timer

is triggered. After the DelayDown timer expires, the DLDP

neighbor information is removed.

Operation Manual – DLDP

H3C S7500 Series Ethernet Switches Chapter 1

DLDP Configuration

1-7

1.2.3 DLDP Timers

Table 1-6 DLDP timers

Timer Description

sending timer

Interval between sending advertisement packets, which can be

configured on a command line interface.

By default, the timer length is 5 seconds.

Probe sending

timer

The interval is 0.5 seconds. In the probe state, DLDP sends two

probe packets in a second.

Echo waiting

timer

It is enabled when DLDP enters the probe state. The echo waiting

timer length is 10 seconds.

If no echo packet is received from the neighbor when the Echo

waiting timer expires, the state of the local end is set to

unidirectional link (one-way audio) and the state machine turns

into the disable state. DLDP outputs log and tracking information,

sends flush packets. Depending on the user-defined DLDP down

mode, DLDP disables the local port automatically or prompts you

to disable the port manually. At the same time, DLDP deletes the

neighbor entry.

Entry aging

timer

When a new neighbor joins, a neighbor entry is created and the

corresponding entry aging timer is enabled

When an advertisement packet is received from a neighbor, the

neighbor entry is updated and the corresponding entry aging

timer is updated

In the normal mode, if no packet is received from the neighbor

when the entry aging timer expires, DLDP sends an

advertisement packet with an RSY tag, and deletes the neighbor

entry.

In the enhanced mode, if no packet is received from the neighbor

when the entry aging timer expires, DLDP enables the enhanced

timer

The entry aging timer length is three times the advertisement

timer length.

Enhanced timer

In the enhanced mode, if no packet is received from the neighbor

when the entry aging timer expires, DLDP enables the enhanced

timer for the neighbor. The enhanced timer length is 10 seconds

The enhanced timer then sends one probe packet every second

and eight packets successively to the neighbor.

If no echo packet is received from the neighbor when the

enhanced timer expires, the state of the local end is set to

unidirectional communication state and the state machine turns

into the disable state. DLDP outputs log and tracking information

and sends flush packets. Depending on the user-defined DLDP

down mode, DLDP disables the local port automatically or

prompts you to disable the port manually. Meanwhile, DLDP

deletes the neighbor entry.

Operation Manual – DLDP

H3C S7500 Series Ethernet Switches Chapter 1

DLDP Configuration

1-8

Timer Description

DelayDown

timer

When a device in the active, advertisement, or probe DLDP state

receives a port down message, it does not removes the

corresponding neighbor immediately, neither does it changes to

the inactive state. Instead, it changes to the delaydown state first.

When a device changes to the delaydown state, the related DLDP

neighbor information remains, and the DelayDown timer is

triggered. The DelayDown timer is configurable and ranges from

1 to 5 seconds.

A device in the delaydown state only responds to port up

messages.

A device in the delaydown state resumes its original DLDP state if

it receives a port up message before the delaydown timer expires.

Otherwise, it removes the DLDP neighbor information and

changes to the inactive state.

1.2.4 DLDP Operating Mode

DLDP can operate in two modes: normal and enhanced.

Table 1-7 DLDP operating mode and neighbor entry aging

DLDP

operating

mode

DLDP detects whether

neighbors exist or not

when neighbor tables

are aging

The entry aging

timer is enabled or

not during neighbor

entry aging

The enhanced

timer is enabled

or not when the

entry aging timer

expires

Normal

mode

Yes (The neighbor

entry ages out after

the entry aging timer

expires)

Enhanced

mode

Yes

Yes (The enhanced

timer is enabled after

the entry aging timer

expires)

Yes (When the

enhanced timer

expires, the state

of the local end is

set to

unidirectional link,

and the neighbor

entry is aged out.)

1.2.5 DLDP Neighbor State

A DLDP neighbor can be in one of these two states: two way and unknown. You can

check the state of a DLDP neighbor by using the display dldp command.

Operation Manual – DLDP

H3C S7500 Series Ethernet Switches Chapter 1

DLDP Configuration

1-9

Table 1-8 Description on the two DLDP neighbor states

DLDP neighbor state Description

two way The link to the neighbor operates properly.

unknown

The device is detecting the neighbor and the neighbor

state is unknown.

1.2.6 Link Auto-recovery Mechanism

If the shutdown mode of a port is set to auto shutdown, the port is set to the DLDP down

state when DLDP detects the link connecting to the port is a unidirectional link. A port in

DLDP down state does not forward service packets or receive/send protocol packets

except DLDPDUs.

A port in the DLDP down state recovers when the corresponding link recovers. A port in

the DLDP down state sends recover probe packets periodically. On receiving a correct

recover echo packet (which means that the unidirectional link is restored to a

bidirectional link), it is brought up by DLDP. The detailed process is as follows.

1) A port in the DLDP down state sends a recover probe packet every 2 seconds.

Recover probe packets carry only the local port information.

2) Upon receiving a recover probe packet, the peer end responds with a recover

echo packet.

3) Upon receiving a recover echo packet, the local end checks to see if the neighbor

information carried in the recover echo packet is consistent with that of the local

port. If yes, the link between the local port and the neighbor is considered to be

recovered to bidirectional, the port changes from the disable state to the active

state, and neighboring relationship is reestablished between the local port and the

neighbor.

 Note:

Only ports in the DLDP down state can send and process recover probe packets and

recover echo packets. The auto-recovery mechanism does apply to ports that are shut

down manually.

Operation Manual – DLDP

H3C S7500 Series Ethernet Switches Chapter 1

DLDP Configuration

1-10

1.3 DLDP Configuration

1.3.1 Configuring DLDP

 Note:

For a port with DLDP enabled, you are not recommended to execute the port monitor

last command on the port. If it is necessary, the value argument in this command must

be less than 10.

Follow these steps to configure DLDP:

To do… Use the command… Remarks

Enter system view

system-view

—

Enable DLDP

globally

dldp enable

Enter

Ethernet

port view

interface interface-type

interface-number

Enable

DLDP

Enable

DLDP

on a

port

Enable

DLDP on

a port

dldp enable

Required.

Enable DLDP

globally and

then enable

DLDP on the

specified port.

Set the authentication mode and

password

dldp authentication-mode

{ none | simple

simple-password | md5

md5-password }

Optional

By default, the

authentication

mode is none,

that is,

authentication

is not

performed.

Set the interval of sending DLDP

packets

dldp interval value

Optional. By

default, the

interval of

sending DLDP

packets is 5

seconds.

Set the delaydown timer

dldp delaydown-timer

delaydown-time

Optional

By default, the

delaydown

timer expires

after 1 second

it is triggered.

Operation Manual – DLDP

H3C S7500 Series Ethernet Switches Chapter 1

DLDP Configuration

1-11

To do… Use the command… Remarks

Set the DLDP handling mode

when an unidirectional link is

detected

dldp

unidirectional-shutdown

{ auto | manual }

Optional

By default, the

handling mode

is auto

Set the operating mode of DLDP

dldp work-mode { enhance

| normal }

Optional

By default,

DLDP works in

normal mode.

Enter Ethernet port view

interface interface-type

interface-number

—

Force the duplex attribute

duplex full

Required

If you want to

use DLDP to

detect which

fiber of the two

fibers is not

connected or

fails, you must

configure the

ports to work in

the mandatory

full duplex

mode.

Force the speed value

speed speed-value

Required

Display the configuration

information about the

DLDP-enabled ports

display dldp [ interface-type

interface-number ]

—

Operation Manual – DLDP

H3C S7500 Series Ethernet Switches Chapter 1

DLDP Configuration

1-12

 Note:

z When you use the dldp enable/dldp disable command in system view to

enable/disable DLDP globally on all optical ports of the switch, this command is only

valid for existing optical ports on the device, however, it is not valid for those added

subsequently.

z DLDP can operate normally only when the same authentication mode and

password are set for local and peer ports.

z When the DLDP protocol works in normal mode, the system can identify only one

type of unidirectional links: cross-connected fibers.

z When the DLDP protocol works in enhanced mode, the system can identify two

types of unidirectional links: the first type is the cross-connected fiber, and the

second type is one of the two fibers is not connected or fails.

z When the device is busy with services and the CPU utilization is high, DLDP may

issue mistaken reports. You are recommended to configure the operating mode of

DLDP as manual after unidirectional links are discovered.

z For the dldp interval integer command, make sure that the same interval for

transmitting advertisement packets is set on the ports used to connected both

devices; otherwise DLDP will not operate properly.

1.3.2 Resetting DLDP Status

 Note:

Only after the ports are DLDP down due to the detection of unidirectional links can you

use the dldp reset command to reset the DLDP status of these ports to retrieve DLDP

probes.

Follow these steps to reset DLDP status:

To do… Use the command… Remarks

Enter system view

system-view

—

Reset the status of DLDP globally

dldp reset

Optional

Operation Manual – DLDP

H3C S7500 Series Ethernet Switches Chapter 1

DLDP Configuration

1-13

To do… Use the command… Remarks

Enter Ethernet port

view

interface interface-type

interface-number

—

Reset the status of

DLDP on 100 M

Ethernet ports

dldp reset

Reset the

status of

DLDP on a

port

Reset the status of

DLDP on Gigabit

Ethernet ports

dldp reset

Optional

Caution:

z This command only applies to the ports in DLDP down status.

z If a port is DLDP down, it can return to the up state automatically. You do not need to

reset DLDP on the port.

1.3.3 Precautions During DLDP Configuration

z DLDP does not work on a port where you configure duplex and rate forcibly, such

as 10 GE port.

z DLDP works only when the link is up.

z To insure that DLDP neighbors can be established properly and unidirectional

links can be detected, you must make sure: DLDP is enabled on both ends, and

the interval of sending DLDP advertisement packets, authentication mode and

password are consistent on both ends.

z You can adjust the interval of sending DLDP advertisement packets (which is 5

seconds by default and in the range of 1 seconds to 100 seconds) in different

network circumstances, so that DLDP can respond rapidly to link failure. The

interval must be shorter than one-third of the STP convergence time, which is

generally 30 seconds. If too long an interval is set, an STP loop may occur before

DLDP shut down unidirectional links. On the contrary, if too short an interval is set,

network traffic increases, and port bandwidth is reduced.

z DLDP is also applicable to STP Discarding ports. Ports discarded by STP can set

up normal DLDP neighbors and detect unidirectional links.

z DLDP does not process any LACP event, and treats each link in the aggregation

group as independent.

z The mandatory duplex mode must be enabled on both ends of the DLDP link. In

this way, unidirectional links will be reported and the ports can be shut down as

required; if the auto-negotiation duplex mode is configured on both ends,

Operation Manual – DLDP

H3C S7500 Series Ethernet Switches Chapter 1

DLDP Configuration

1-14

unidirectional links will not be reported and ports will not be shut down, while only

the state of DLDP neighbors changes.

z If DLDP is enabled after unidirectional links appear, DLDP cannot detect

unidirectional links.

z DLDP cannot be used together with similar protocols of other companies, that is,

you cannot enable DLDP on one end and enable one of the similar protocols of

other companies.

For XGbus products, pay attention to the following points:

z When interface boards are hot swapped, if the plugged interface board is of the

same type as the pulled interface board, DLDP restores automatically.

z When active/standby switchover is performed on an SRPU, the standby SRPU

detects unidirectional links instead of the SRPU. DLDP parameters remain the

same and unidirectional links are detected again on each port.

1.4 DLDP Network Example

I. Network requirements

As shown in Figure 1-3:

z Switch A and Switch B are connected through two pairs of fibers. Both of them

support DLDP;

z Suppose the fibers between Switch A and Switch B are cross-connected. DLDP

disconnects the unidirectional links after detecting them;

z When the network administrator connects the fiber correctly, the ports taken down

by DLDP are restored.

II. Network diagram

Switch

Switc

GE2/0/3

GE2/0/4

Switch

Switc

GE2/0/3

GE2/0/4

Figure 1-3 Fiber cross-connection

III. Configuration procedure

1) Configure Switch A

# Configure the ports to work in mandatory full duplex mode at the speed of 1000 Mbps.

Operation Manual – DLDP

H3C S7500 Series Ethernet Switches Chapter 1

DLDP Configuration

1-15

<H3CA> system-view

[H3CA] interface gigabitethernet 2/0/3

[H3CA-GigabitEthernet2/0/3] duplex full

[H3CA-GigabitEthernet2/0/3] speed 1000

[H3CA-GigabitEthernet2/0/3] quit

[H3CA] interface gigabitethernet 2/0/4

[H3CA-GigabitEthernet2/0/4] duplex full

[H3CA-GigabitEthernet2/0/4] speed 1000

[H3CA-GigabitEthernet2/0/4] quit

# Enable DLDP globally

[H3CA] dldp enable

# Set the interval of sending DLDP packets to 15 seconds

[H3CA] dldp interval 15

# Configure DLDP to work in enhanced mode

[H3CA] dldp work-mode enhance

# Set the DLDP handling mode to auto after unidirectional links are detected

[H3CA] dldp unidirectional-shutdown auto

# Display the DLDP status

[H3CA] display dldp

 Note:

If the fibers are correctly connected between the two switches, the system displays the

connections with the neighbor as bidirectional links.

When the fibers are not correctly connected:

z When the fibers are cross-connected, both ends are unidirectional links and the two

ends are displayed as in Disable status;

z When one end is correctly connected and the other end is not connected, one end is

in Advertisement status and the other is in Inactive status.

# Restore the ports taken down by DLDP

[H3CA] dldp reset

2) Configure Switch B

The configuration of Switch B is the same to that of Switch A.

Operation Manual – DLDP

H3C S7500 Series Ethernet Switches Chapter 1

DLDP Configuration

1-16

 Note:

Suppose the port works in the mandatory full duplex mode and the connection at both

ends of the link is normal. After DLDP is enabled, if the optical fiber in one end is not

connected, DLDP will report that the link is a unidirectional link.

H3C S7500 Series Operating instructions

Brand: H3C

Model: S7500 Series

Type: Operating instructions

Advanced Layer 2 and Layer 3 Switching: Provides comprehensive Layer 2 and Layer 3 switching features, including VLANs, QoS, and routing protocols, allowing for flexible network segmentation, traffic prioritization, and efficient routing.
High Scalability: Supports stacking technology, enabling multiple switches to be interconnected and managed as a single logical unit, providing scalability and redundancy.

Download PDF

report

H3C S7500 Series Operating instructions

H3C S7500 Series Operating instructions

Related papers

Other documents