Operation Manual – Telnet ProtectionH3C S7500 Series Ethernet Switches Chapter 1 Telnet Protection Configuration1-1Chapter 1 Telnet Protection ConfigurationWhen configuring Telnet protection, go to these sections for information you areinterested in:z Introductionz Telnet Protection Configuration1.1 IntroductionThe Telnet protection function is used to protect Telnet packets, SNMP packets, andICMP packets from the specific source IP addresses in the case of attacks against thenetwork or high CPU utilization.Telnet protection comes in global Telnet protection, special ARP Telnet protection, anddefault-route Telnet protection. Global Telnet protection is the highest in priority; thencomes special ARP Telnet protection and default-route Telnet protection is the lowest inpriority.After you configure global Telnet protection, all the Layer-3 interfaces are protected.You can also configure special ARP Telnet protection to protect specified Layer-3interfaces. If the default route exists, you can enable special ARP Telnet protection onthe gateway of the network segment where the next hop of the default route residesthrough enabling default-route Telnet protection. By default, default-route Telnetprotection is disabled.Before configuring Telnet protection, you need to enable Telnet, SNMP, and ICMPprotection respectively. You can configure Telnet protection, SNMP protection, andICMP protection for only the packets of the specific source IP addresses.Caution:After the network address translation (NAT) function is enabled,z You cannot configure global Telnet protection.z You cannot configure special ARP Telnet protection for the Layer-3 interface whereNAT resides.z You cannot configure default-route Telnet protection.
