H3C S5810 Series, Руководство по эксплуатации

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Disadvantages of sending ICMP error packets
Although sending ICMP error packets facilitates network control and management, it still has the
following disadvantages:
z
Sending a lot of ICMP packets will increase network traffic.
z
If a device receives a lot of malicious packets that cause it to send ICMP error packets, its
performance will be reduced.
z
As the redirection function increases the routing table size of a host, the host’s performance will be
reduced if its routing table becomes very large.
z
If a host sends malicious ICMP destination unreachable packets, end users may be affected.
To prevent such problems, you can disable the device from sending ICMP error packets.
Follow these steps to enable sending of ICMP error packets:
To do… Use the command… Remarks
Enter system view system-view —
Enable sending of ICMP redirect packets ip redirects enable
Required
Disabled by default.
Enable sending of ICMP timeout packets ip ttl-expires enable
Required
Disabled by default.
Enable sending of ICMP destination
unreachable packets
ip unreachables enable
Required
Disabled by default.
The device stops sending “TTL timeout” ICMP error packets after sending ICMP timeout packets is
disabled. However, “reassembly timeout” error packets will be sent normally.
Displaying and Maintaining IP Performance Optimization
To do… Use the command… Remarks
Display current TCP connection
state
display tcp status Available in any view
Display TCP connection statistics display tcp statistics Available in any view
Display UDP statistics display udp statistics Available in any view
Display statistics of IP packets display ip statistics Available in any view
Display ICMP statistics display icmp statistics Available in any view
Display socket information
display ip socket [ socktype
sock-type ] [ task-id socket-id ]
Available in any view
Display FIB information
display fib [ | { begin | include |
exclude } regular-expression | acl
acl-number | ip-prefix
ip-prefix-name ]
Available in any view