Hosts Can Ping The Public Network, But The Network Speed Is Low; When The Device Functions As A Pppoe Client, It Cannot Dynamically Obtain The Dns Server Address - Huawei AR530 Series Configuration Manual

Huawei AR530&AR550 Series Industrial Switch Routers
Configuration Guide - WAN
3.8.1 Hosts Can Ping the Public Network, But the Network Speed
is Low
Fault Description
When a host dials up to the Internet, the host can ping the public network, but network speed is
low and web pages cannot be opened.
Fault Analysis
The maximum transmission unit (MTU) of the PPPoE-enabled interface is 1492 bytes. When
the packet to be forwarded by the interface is larger than the MTU and the packet is configured
as non-fragmented, the packet is discarded and the network speed is low. Configure the MSS
negotiated in the TCP negotiation phase using the tcp adjust-mss command on the dialer
interface. In this way, the length of packets is smaller than the MTU and packets can be properly
processed, which resolves the problem of low network speed.
The recommended value of tcp adjust-mss is 1200 for PPPoE applications.
Procedure
Step 1 Run the tcp adjust-mss value command in the dialer interface view to set the MSS of TCP
packets on the interface.
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3.8.2 When the Device Functions as a PPPoE Client, It Cannot
Dynamically Obtain the DNS Server Address
Fault Description
When the device functions as a PPPoE client, it cannot dynamically obtain the DNS server
address.
Procedure
Step 1 Configure the PPPoE client to receive the DNS server address assigned by the remote device
using either or both of the following commands:
l In the dialer interface view, run the ppp ipcp dns request command to configure the
l In the dialer interface view, run the ppp ipcp dns admit-any command to configure the
Issue 01 (2014-11-30)
industrial switch router to proactively request the remote device to specify the DNS server
address.
By default, the industrial switch router is disabled from requesting a DNS server address
from the remote device.
industrial switch router to passively receive the DNS server address specified by the remote
device.
By default, the industrial switch router does not accept the DNS server IP address specified
by the remote device.
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